Supplemental Guarantor Financial Information - I/S (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Consolidated Statements of Comprehensive Income (Loss)
Ownership, as a percent	100.00%
Revenues	$ 357,572	$ 303,247
Operating expenses	353,465	273,214
Income from operations	4,107	30,033
Interest expense (income), net, including amortization of deferred financing costs and note discount	9,533	7,274
Other (income) expense	(1,580)	(555)
(Loss) income before income taxes	(3,846)	23,314
Income tax (benefit) expense	(2,952)	7,955
Net (loss) income	(894)	15,359
Net income (loss) attributable to noncontrolling interests	7	(25)
Net (loss) income attributable to controlling interests and available to common shareholders	(901)	15,384
Other comprehensive income (loss), attributable to controlling interest	8,652	(16,077)
Comprehensive income (loss) attributable to controlling interests	7,751	(693)
Consolidation Eliminations
Condensed Consolidated Statements of Comprehensive Income (Loss)
Revenues	(2,442)	(3,188)
Operating expenses	(1,410)	(3,183)
Income from operations	(1,032)	(5)
Equity in earnings of subsidiaries	56,849	37,408
Other (income) expense	36,323
(Loss) income before income taxes	(94,204)	(37,413)
Net (loss) income	(94,204)	(37,413)
Net income (loss) attributable to noncontrolling interests	7	(25)
Net (loss) income attributable to controlling interests and available to common shareholders	(94,211)	(37,388)
Other comprehensive income (loss), attributable to controlling interest	(8,653)	15,955
Comprehensive income (loss) attributable to controlling interests	(102,864)	(21,433)
Parent
Condensed Consolidated Statements of Comprehensive Income (Loss)
Operating expenses	5,899
Income from operations	(5,899)
Equity in earnings of subsidiaries	(4,744)	(15,359)
Other (income) expense	64
(Loss) income before income taxes	(1,219)	15,359
Income tax (benefit) expense	(325)
Net (loss) income	(894)	15,359
Net (loss) income attributable to controlling interests and available to common shareholders	(894)	15,359
Other comprehensive income (loss), attributable to controlling interest	8,652	(16,077)
Comprehensive income (loss) attributable to controlling interests	7,758	(718)
Issuer
Condensed Consolidated Statements of Comprehensive Income (Loss)
Operating expenses	9,718	7,502
Income from operations	(9,718)	(7,502)
Interest expense (income), net, including amortization of deferred financing costs and note discount	6,091	6,368
Equity in earnings of subsidiaries	(7,376)	(24,302)
Other (income) expense	(56)	(346)
(Loss) income before income taxes	(8,377)	10,778
Income tax (benefit) expense	(6,144)	(5,275)
Net (loss) income	(2,233)	16,053
Net (loss) income attributable to controlling interests and available to common shareholders	(2,233)	16,053
Other comprehensive income (loss), attributable to controlling interest	1,443	(1,287)
Comprehensive income (loss) attributable to controlling interests	(790)	14,766
Guarantors
Condensed Consolidated Statements of Comprehensive Income (Loss)
Revenues	207,359	209,167
Operating expenses	192,872	180,835
Income from operations	14,487	28,332
Interest expense (income), net, including amortization of deferred financing costs and note discount	5,952	358
Equity in earnings of subsidiaries	(44,729)	2,253
Other (income) expense	7,291	(1,109)
(Loss) income before income taxes	45,973	26,830
Income tax (benefit) expense	3,873	11,466
Net (loss) income	42,100	15,364
Net (loss) income attributable to controlling interests and available to common shareholders	42,100	15,364
Other comprehensive income (loss), attributable to controlling interest	2,631	(8,743)
Comprehensive income (loss) attributable to controlling interests	44,731	6,621
Non-Guarantors
Condensed Consolidated Statements of Comprehensive Income (Loss)
Revenues	152,655	97,268
Operating expenses	146,386	88,060
Income from operations	6,269	9,208
Interest expense (income), net, including amortization of deferred financing costs and note discount	(2,510)	548
Other (income) expense	(45,202)	900
(Loss) income before income taxes	53,981	7,760
Income tax (benefit) expense	(356)	1,764
Net (loss) income	54,337	5,996
Net (loss) income attributable to controlling interests and available to common shareholders	54,337	5,996
Other comprehensive income (loss), attributable to controlling interest	4,579	(5,925)
Comprehensive income (loss) attributable to controlling interests	$ 58,916	$ 71