5. Goodwill and Indefinite-Lived Intangible Assets and Other Long-Term Assets (Tables)
|12 Months Ended|
Dec. 31, 2018
|Goodwill and Intangible Assets Disclosure [Abstract]|
|Reconciliation of Change in Carrying Value of Goodwill||
Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef