Annual report pursuant to Section 13 and 15(d)

10. Share-Based Compensation (Details - Option activity)

v2.4.1.9
10. Share-Based Compensation (Details - Option activity) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Employee Stock Option [Member]    
Options outstanding, beginning balance 5,222,430us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
4,985,480us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Options granted 1,080,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
2,304,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Options exercised (1,984,080)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
(55,379)us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Options forfeited/expired (132,422)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
(2,011,671)us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Options outstanding, ending balance 4,185,928us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
5,222,430us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Options vested or expected to vest 4,185,928us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
 
Options exercisable 2,630,024us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
4,063,646us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Weighted-average exercise price outstanding, beginning balance $ 0.47us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
$ 0.42us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Weighted-average exercise price, granted $ 0.31us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
$ 1.22us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Weighted-average exercise price, exercised $ 0.05us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
$ 0.04us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Weighted-average exercise price, forfeited/expired $ 0.93us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
$ 1.22us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Weighted-average exercise price, ending balance $ 0.62us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
$ 0.47us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Weighted-average exercise price, vested or expected to vest $ 0.62us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
 
Weighted-average exercise price, exercisable $ 0.60us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
$ 0.30us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Weighted-average remaining life outstanding 6 years 10 months 10 days 4 years 8 months 5 days
Weighted-average remaining life, vested or expected to vest 6 years 10 months 10 days  
Weighted-average remaining life, exercisable 5 years 5 months 23 days 3 years 8 months 19 days
Aggregate intrinsic value, outstanding beginning balance $ 432,392us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
 
Aggregate intrinsic value, exercised 509,622us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
10,663us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Aggregate intrinsic value, outstanding ending balance 80,338us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
432,392us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Aggregate intrinsic value, vested or expected to vest 80,338us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
 
Aggregate intrinsic value, exercisable 80,338us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
432,392us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Non Employee Stock Options [Member]    
Options outstanding, beginning balance 415,520us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
415,520us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
Options granted 480,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
Options exercised 0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
0us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
Options forfeited/expired 0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
0us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
Options outstanding, ending balance 895,520us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
415,520us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
Options vested or expected to vest 895,520us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
 
Options exercisable 383,664us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
127,736us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
Weighted-average exercise price outstanding, beginning balance $ 0.52us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
$ 0.52us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
Weighted-average exercise price, granted $ 0.25us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
 
Weighted-average exercise price, ending balance $ 0.39us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
$ 0.52us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
Weighted-average exercise price, vested or expected to vest $ 0.39us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
 
Weighted-average exercise price, exercisable $ 0.42us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
$ 0.48us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
Weighted-average remaining life outstanding 7 years 7 months 6 days 5 years 10 months 24 days
Weighted-average remaining life, vested or expected to vest 7 years 7 months 6 days  
Weighted-average remaining life, exercisable 6 years 4 months 24 days 4 years 4 months 17 days
Aggregate intrinsic value, outstanding beginning balance 49us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
 
Aggregate intrinsic value, outstanding ending balance 159us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
49us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
Aggregate intrinsic value, vested or expected to vest 159us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableAggregateIntrinsicValue
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
 
Aggregate intrinsic value, exercisable $ 159us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember
$ 49us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1
/ us-gaap_AwardTypeAxis
= xbio_NonEmployeeStockOptionsMember