Unaudited Condensed Consolidated Statement of Operations Statement - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Unaudited Condensed Consolidated Statement of Operations [Abstract]
Revenue	$ 721,467	$ 714,453	$ 2,222,083	$ 2,216,761
Costs and expenses	(580,722)	(572,774)	(1,756,425)	(1,729,974)
Gross profit	140,745	141,679	465,658	486,787
General and administrative expenses	(26,916)	(27,895)	(102,668)	(96,947)
Gains (losses) on divestitures and impairment charges, net	557	10,764	(30,432)	3,403
Operating income	114,386	124,548	332,558	393,243
Interest expense	(39,508)	(43,921)	(121,988)	(129,842)
Loss on early extinguishment of debt	(25)	(6,918)	(22,503)	(6,918)
Other income (expense), net	110	336	(697)	169
Income before income taxes	74,963	74,045	187,370	256,652
Provision for income taxes	(27,422)	(26,118)	(76,482)	(93,778)
Net income from continuing operations	47,541	47,927	110,888	162,874
Net loss from discontinued operations, net of tax	0	0	0	(390)
Net income	47,541	47,927	110,888	162,484
Net loss (income) attributable to noncontrolling interests	186	(479)	(96)	(1,066)
Net income attributable to common stockholders	$ 47,727	$ 47,448	$ 110,792	$ 161,418
Basic earnings per share:
Net income attributable to common stockholders, basic	$ 0.25	$ 0.24	$ 0.57	$ 0.80
Basic weighted average number of shares	193,274	199,310	193,999	201,729
Diluted earnings per share:
Net income attributable to common stockholders, diluted	$ 0.24	$ 0.23	$ 0.56	$ 0.78
Diluted weighted average number of shares	196,567	203,444	197,175	205,950
Dividends declared per share	$ 0.13	$ 0.12	$ 0.38	$ 0.32