Supplemental Information	9 Months Ended
Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplemental Information	Supplemental Information Accounts Payable, Accruals and Other Liabilities At September 30, 2019 and December 31, 2018, accruals and other liabilities included accrued media of $163,777 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. Goodwill balances as of each of September 30, 2019 and December 31, 2018, were $740,955. Income Taxes Our tax provision for interim periods is determined using an estimated annual effective tax rate, adjusted for discrete items arising in interim periods. Income tax expense for the three months ended September 30, 2019 was $3,457 (on income of $8,907 resulting in an effective tax rate of 38.8%) compared to an expense of $2,986 (on loss of $10,981 resulting in an effective tax rate of 27.2%) for the three months ended September 30, 2018. Income tax expense for the nine months ended September 30, 2019 was $6,292 (on income of $19,102 resulting in an effective tax rate of 32.9%) compared to a benefit of $3,367 (on a loss of $39,960 resulting in an effective tax rate of 8.4%) for the nine months ended September 30, 2018. The income tax expense and benefit for the three and nine months of 2018, respectively, were impacted by impairments and non-deductible stock compensation for which a tax benefit was not recognized.

Supplemental Information

Accounts Payable, Accruals and Other Liabilities

At September 30, 2019 and December 31, 2018, accruals and other liabilities included accrued media of $163,777 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. Goodwill balances as of each of September 30, 2019 and December 31, 2018, were $740,955.

Income Taxes

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

Income tax expense for the three months ended September 30, 2019 was $3,457 (on income of $8,907 resulting in an effective tax rate of 38.8%) compared to an expense of $2,986 (on loss of $10,981 resulting in an effective tax rate of 27.2%) for the three months ended September 30, 2018.

Income tax expense for the nine months ended September 30, 2019 was $6,292 (on income of $19,102 resulting in an effective tax rate of 32.9%) compared to a benefit of $3,367 (on a loss of $39,960 resulting in an effective tax rate of 8.4%) for the nine months ended September 30, 2018.

The income tax expense and benefit for the three and nine months of 2018, respectively, were impacted by impairments and non-deductible stock compensation for which a tax benefit was not recognized.