Supplemental Information	3 Months Ended
Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplemental Information	Supplemental Information Accounts Payable, Accruals and Other Liabilities At March 31, 2019 and December 31, 2018, accruals and other liabilities included accrued media of $137,975 and $180,586, respectively; and also included amounts due to noncontrolling interest holders for their share of profits. See Note 9 of the Notes to the Unaudited Condensed Consolidated Financial Statements included herein for additional information regarding noncontrolling interest holders share of profits. Goodwill and Indefinite Lived Intangibles Goodwill and indefinite life intangible assets (trademarks) acquired as a result of a business combination which are not subject to amortization are tested for impairment annually as of October 1st of each year, or more frequently if indicators of potential impairment exist. For goodwill, impairment is assessed at the reporting unit level. For the three months ended March 31, 2019 and the year ended December 31, 2018, goodwill was $742,775 and $740,955, respectively. Income Taxes Our tax provision for interim periods is determined using an estimated annual effective tax rate, adjusted for discrete items arising in the quarter. Income tax expense for the three months ended March 31, 2019 was $748 (on income of $981 resulting in an effective tax rate of 76.3%) compared to a benefit of $8,330 (on a loss of $36,935 resulting in an effective tax rate of 22.6%) for the three months ended March 31, 2018. The effective tax rate of 76.3% was primarily related to the impact of certain discrete items recognized for the three months ended March 31, 2019.

Supplemental Information

Accounts Payable, Accruals and Other Liabilities

At March 31, 2019 and December 31, 2018, accruals and other liabilities included accrued media of $137,975 and $180,586, respectively; and also included amounts due to noncontrolling interest holders for their share of profits. See Note 9 of the Notes to the Unaudited Condensed Consolidated Financial Statements included herein for additional information regarding noncontrolling interest holders share of profits.

Goodwill and Indefinite Lived Intangibles

Goodwill and indefinite life intangible assets (trademarks) acquired as a result of a business combination which are not subject to amortization are tested for impairment annually as of October 1st of each year, or more frequently if indicators of potential impairment exist. For goodwill, impairment is assessed at the reporting unit level. For the three months ended March 31, 2019 and the year ended December 31, 2018, goodwill was $742,775 and $740,955, respectively.

Income Taxes

Our tax provision for interim periods is determined using an estimated annual effective tax rate, adjusted for discrete items arising in the quarter.

Income tax expense for the three months ended March 31, 2019 was $748 (on income of $981 resulting in an effective tax rate of 76.3%) compared to a benefit of $8,330 (on a loss of $36,935 resulting in an effective tax rate of 22.6%) for the three months ended March 31, 2018. The effective tax rate of 76.3% was primarily related to the impact of certain discrete items recognized for the three months ended March 31, 2019.