Supplemental Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued media	$ 163,777		$ 163,777		$ 180,586
Goodwill	740,955		740,955
Income tax expense (benefit)	3,457	$ 2,986	6,292	$ (3,367)
Income (loss) before income taxes and equity in earnings of non-consolidated affiliates	$ 8,907	$ (10,981)	$ 19,102	$ (39,960)
Effective tax rate (percent)			38.80%	27.20%

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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