Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Operating revenues	$ 443,885	$ 417,708
Cost of services (excluding depreciation and amortization shown below)	215,565	219,061
Selling, general and administrative expenses	114,406	128,224
Depreciation and amortization	46,843	49,219
Total operating expenses	376,814	396,504
Operating income	67,071	21,204
Interest expense:
Interest income	414	978
Interest expense	18,193	19,703
Total interest expense, net	(17,779)	(18,725)
(Loss)/gain on investments and other, net	(3,047)	734
Income from continuing operations before equity in earnings/(losses) of affiliates and income taxes	46,245	3,213
Provision for income taxes	12,951	1,058
Income from continuing operations before equity in earnings/(losses) of affiliates	33,294	2,155
Equity in earnings/(losses) of affiliates, net of tax	512	(422)
Net income from continuing operations	33,806	1,733
Income/(loss) from discontinued operations, net of tax	13	(46)
Net income	$ 33,819	$ 1,687
Basic income per share:
Net income from continuing operations (usd per share)	$ 0.43	$ 0.02
Loss from discontinued operations, net of tax (usd per share)	0	0
Net (loss)/income (usd per share)	0.43	0.02
Diluted income per share:
Net income from continuing operations (usd per share)	0.42	0.02
Loss from discontinued operations, net of tax (usd per share)	0	0
Net (loss)/income (usd per share)	$ 0.42	$ 0.02
Weighted-average common shares outstanding:
Basic (in shares)	79,028	80,179
Diluted (in shares)	80,525	81,277