Consolidated Statement of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Product Information [Line Items]
Revenue	$ 3,230,785	$ 3,190,174	$ 3,095,031
Costs of revenue	(2,470,205)	(2,429,852)	(2,372,252)
Gross profit	760,580	760,322	722,779
Corporate general and administrative expenses	(126,886)	(145,596)	(158,651)
Gains on divestitures and impairment charges, net	32,919	15,933	7,015
Operating income	666,613	630,659	571,143
Interest expense	(185,843)	(181,556)	(169,125)
Losses on early extinguishment of debt, net	(16,637)	(10,131)	(274)
Other income (expense), net	299	2,760	(1,486)
Income before income taxes	464,432	441,732	400,258
(Provision for) benefit from income taxes	(94,661)	5,826	146,589
Net income	369,771	447,558	546,847
Net income attributable to noncontrolling interests	(175)	(350)	(184)
Net income attributable to common stockholders	$ 369,596	$ 447,208	$ 546,663
Basic earnings per share:
Net income attributable to common stockholders, basic	$ 2.03	$ 2.45	$ 2.91
Basic weighted average number of shares	182,246	182,447	187,630
Diluted earnings per share:
Net income attributable to common stockholders, diluted	$ 1.99	$ 2.39	$ 2.84
Diluted weighted average number of shares	185,523	186,972	192,246
Dividends declared per share	$ 0.68	$ 0.58
Product [Member]
Product Information [Line Items]
Revenue	$ 1,610,158	$ 1,584,242	$ 1,525,747
Costs of revenue	(829,158)	(811,574)	(794,725)
Service [Member]
Product Information [Line Items]
Revenue	1,379,001	1,374,380	1,356,665
Costs of revenue	(769,119)	(752,488)	(729,204)
Product and Service, Other [Member]
Product Information [Line Items]
Revenue	241,626	231,552	212,619
Costs of revenue	$ (871,928)	$ (865,790)	$ (848,323)