Segment Information - Reconciliation of Segment Gross Contribution to Net Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Costs and expenses:
Cost of services and product development	$ 341,278	$ 346,645
Selling, general and administrative	496,639	518,770
Acquisition and integration charges	1,560	2,772
Operating income	124,718	48,799
Interest expense and other, net	(27,864)	(25,671)
Loss from divested operations	0	(2,075)
Less: Provision for income taxes	21,757	258
Net income	75,097	20,795
Reportable segments
Costs and expenses:
Operating income	$ 676,791	622,762
Reportable segments | Maximum
Costs and expenses:
Percent of target bonus allocated to segments	100.00%
Corporate and other expenses
Costs and expenses:
Cost of services and product development	$ (822)	(1,037)
Selling, general and administrative	496,639	518,770
Depreciation and amortization	54,696	53,458
Acquisition and integration charges	1,560	2,772
Operating income	$ (552,073)	$ (573,963)