Unaudited Quarterly Financial Data - Statement of Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Selected Quarterly Financial Results (Unaudited)
Revenue	$ 393,586	$ 373,545	$ 390,849	$ 404,357	$ 399,643	$ 383,030	$ 410,382	$ 393,167	$ 795,206	$ 803,549	$ 1,168,751	$ 1,186,579	$ 1,562,337	$ 1,586,222	$ 1,145,891
Cost of revenue (exclusive of depreciation and amortization)	314,858	295,445	303,831	310,601	306,654	296,685	315,167	294,897	614,432	610,064	909,877	906,749	1,224,735	1,213,403	827,544
Selling, general and administrative expenses (exclusive of depreciation and amortization)	49,678	48,347	51,162	49,677	48,114	44,897	46,378	45,519	100,839	91,897	149,186	136,794	198,864	184,908	220,955
Depreciation and amortization	24,421	25,079	24,779	26,624	33,684	33,410	34,744	36,239	51,403	70,982	76,482	104,393	100,903	138,077	98,890
Impairment of goodwill and other intangible assets	252,399	97,158			48,127						97,158		349,557	48,127	69,437
Related party expense	1,742	1,430	5,331	998	3,664	775	6,783	1,181	6,329	7,964	7,759	8,739	9,501	12,403	33,431
Operating loss	(249,512)	(93,914)	5,746	16,457	(40,600)	7,263	7,310	15,331	22,203	22,642	(71,711)	29,904	(321,223)	(10,696)	(104,366)
Other expense (income), net:
Interest expense, net	43,216	40,573	39,959	39,701	38,999	39,087	39,229	38,676	79,660	77,905	120,235	116,992	163,449	155,991	129,676
Debt modification and extinguishment costs			1,404			1,067			1,404		1,404	1,067	1,404	1,067	35,512
Sundry expense (income),net	(600)	165	(1,311)	2,715	905	(2,283)	(2,122)	229	1,404	(1,893)	1,569	(4,176)	(969)	3,271	(2,295)
Other expense (income), net	10,003	406	2,527	1,493	2,567	(1,069)	(907)	(3,621)	4,020	(4,528)	4,424	(5,597)	14,429	(3,030)	(1,297)
Net loss before income taxes	(302,131)	(135,058)	(36,833)	(27,452)	(83,071)	(29,539)	(28,890)	(19,953)	(64,285)	(48,842)	(199,343)	(78,382)	(501,474)	(161,453)	(270,552)
Income tax (expense) benefit	(1,953)	3,769	(4,738)	(4,720)	(3,442)	733	(1,619)	(4,025)	(9,458)	(5,644)	(5,689)	(4,911)	(7,642)	(8,353)	61,068
Net loss	(304,084)	(131,289)	(41,571)	(32,172)	(86,513)	(28,806)	(30,509)	(23,978)	(73,743)	(54,486)	(205,032)	(83,293)	(509,116)	(169,806)	(209,484)
Cumulative dividends for Series A Preferred Stock	(597)	(884)	(914)	(914)	(914)	(914)	(914)	(914)	(1,828)	(1,828)	(2,712)	(2,742)	(3,309)	(3,655)	(2,489)
Net loss attributable to common stockholders	$ (304,681)	$ (132,173)	$ (42,485)	$ (33,086)	$ (87,427)	$ (29,720)	$ (31,423)	$ (24,892)	(75,571)	(56,314)	(207,744)	(86,035)	$ (512,425)	$ (173,461)	$ (228,348)
Weighted average outstanding common shares	146,161,353	145,636,749	145,466,193	145,572,221	147,773,089	147,092,936	147,688,855	147,569,383
Earnings per share:
(Understatement) / overstatement of loss per share	$ (2.09)	$ (0.91)	$ (0.29)	$ (0.23)	$ (0.59)	$ (0.20)	$ (0.21)	$ (0.17)					$ (3.52)	$ (1.17)	$ (2.18)
ITPS
Selected Quarterly Financial Results (Unaudited)
Revenue	$ 306,665	$ 292,607	$ 309,840	$ 325,172	$ 324,267	$ 307,313	$ 330,131	$ 311,936					$ 1,234,284	$ 1,273,647	$ 820,677
Cost of revenue (exclusive of depreciation and amortization)	250,927	241,867	249,589	259,272	255,191	247,021	262,066	246,042					1,001,655	1,010,320	619,694
HS
Selected Quarterly Financial Results (Unaudited)
Revenue	69,806	62,132	63,440	61,343	56,293	56,776	56,314	58,632					256,721	228,015	233,595
Cost of revenue (exclusive of depreciation and amortization)	53,634	42,717	43,353	40,341	40,008	37,139	39,538	35,192					180,045	151,877	152,290
LLPS
Selected Quarterly Financial Results (Unaudited)
Revenue	17,115	18,806	17,569	17,842	19,083	18,941	23,937	22,599					71,332	84,560	91,619
Cost of revenue (exclusive of depreciation and amortization)	$ 10,297	10,861	10,889	10,988	11,455	12,525	13,563	13,663					$ 43,035	51,206	55,560
As previously reported
Selected Quarterly Financial Results (Unaudited)
Revenue		372,917	390,160	403,765	399,643	383,030	410,382	393,167	793,924	803,549	1,166,841	1,186,579		1,586,222	1,152,324
Cost of revenue (exclusive of depreciation and amortization)		291,222	298,006	306,882	306,192	295,936	313,954	293,792	604,888	607,746	896,110	903,682		1,209,874	829,143
Selling, general and administrative expenses (exclusive of depreciation and amortization)		50,372	51,564	49,949	47,420	44,913	46,723	45,595	101,513	92,318	151,884	137,231		184,651	220,955
Depreciation and amortization		27,114	27,191	28,020	36,057	35,041	36,368	38,019	55,211	74,386	82,326	109,428		145,485	98,890
Impairment of goodwill and other intangible assets		99,682			48,127						99,682			48,127	69,437
Related party expense		1,405	1,055	994	1,068	759	1,402	1,105	2,049	2,507	3,454	3,267		4,334	33,431
Operating loss		(96,878)	12,344	17,920	(39,221)	6,381	11,935	14,656	30,263	26,592	(66,615)	32,971		(6,249)	(99,532)
Other expense (income), net:
Interest expense, net		39,747	39,132	38,899	38,212	38,339	38,527	38,017	78,031	76,544	117,778	114,883		153,095	128,489
Debt modification and extinguishment costs			1,404			1,067			1,404		1,404	1,067		1,067	35,512
Sundry expense (income),net		(10)	(1,493)	2,531	1,689	(2,571)	(2,325)	(64)	1,038	(2,389)	1,028	(4,961)		3,271	(2,295)
Other expense (income), net		581	2,709	1,677	1,783	(781)	(704)	(3,328)	4,386	(4,032)	4,965	(4,813)		(3,030)	(1,297)
Net loss before income taxes		(137,196)	(29,408)	(25,187)	(80,905)	(29,673)	(23,563)	(19,969)	(54,596)	(43,531)	(191,790)	(73,205)		(154,110)	(264,531)
Income tax (expense) benefit		3,769	(4,738)	(4,720)	(3,496)	733	(1,619)	(4,025)	(9,458)	(5,644)	(5,689)	(4,911)		(8,407)	60,246
Net loss		(133,427)	(34,146)	(29,907)	(84,401)	(28,940)	(25,182)	(23,994)	(64,054)	(49,175)	(197,479)	(78,116)		(162,517)	(204,285)
Cumulative dividends for Series A Preferred Stock		(884)	(914)	(914)	(914)	(914)	(914)	(914)	(1,828)	(1,828)	(2,712)	(2,742)		(3,655)	(2,489)
Net loss attributable to common stockholders		(134,311)	(35,060)	(30,821)	(85,315)	(29,854)	(26,096)	(24,908)	(65,882)	(51,003)	(200,191)	(80,858)		$ (166,172)	$ (223,149)
Earnings per share:
(Understatement) / overstatement of loss per share														$ (1.09)	$ (2.08)
Adjustment
Selected Quarterly Financial Results (Unaudited)
Revenue		628	689	592					1,282		1,910				$ (6,433)
Cost of revenue (exclusive of depreciation and amortization)		4,223	5,825	3,719	462	749	1,213	1,105	9,544	2,318	13,767	3,067		$ 3,529	(1,599)
Selling, general and administrative expenses (exclusive of depreciation and amortization)		(2,025)	(402)	(272)	694	(16)	(345)	(76)	(674)	(421)	(2,698)	(437)		257
Depreciation and amortization		(2,035)	(2,412)	(1,396)	(2,373)	(1,631)	(1,624)	(1,780)	(3,808)	(3,404)	(5,844)	(5,035)		(7,408)
Impairment of goodwill and other intangible assets		(2,524)									(2,524)
Related party expense		25	4,276	4	2,596	16	5,381	76	4,280	5,457	4,305	5,472		8,069
Operating loss		2,964	(6,598)	(1,463)	(1,379)	882	(4,625)	675	(8,060)	(3,950)	(5,096)	(3,067)		(4,447)	(4,834)
Other expense (income), net:
Interest expense, net		826	827	802	787	748	702	659	1,629	1,361	2,457	2,109		2,896	1,187
Sundry expense (income),net		175	182	184	(784)	288	203	293	366	496	541	785
Other expense (income), net		(175)	(182)	(184)	784	(288)	(203)	(293)	(366)	(496)	(541)	(784)
Net loss before income taxes		2,138	(7,425)	(2,265)	(2,166)	134	(5,327)	16	(9,689)	(5,311)	(7,553)	(5,177)		(7,343)	(6,021)
Income tax (expense) benefit					54									54	822
Net loss		2,138	(7,425)	(2,265)	(2,112)	134	(5,327)	16	(9,689)	(5,311)	(7,553)	(5,177)		(7,289)	(5,199)
Net loss attributable to common stockholders		$ 2,138	$ (7,425)	$ (2,265)	$ (2,112)	$ 134	$ (5,327)	$ 16	$ (9,689)	$ (5,311)	$ (7,553)	$ (5,177)		$ (7,289)	$ (5,199)
Earnings per share:
(Understatement) / overstatement of loss per share														$ (0.08)	$ (0.10)