Consolidated Statements of Operations - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2018	Dec. 31, 2016
Income Statement [Abstract]
Net service revenues	$ 1,713,579	$ 1,673,029	$ 2,353,603	$ 2,185,302
Cost of services provided	1,259,822	1,208,233	1,727,524	1,578,141
Gross profit	453,757	464,796	626,079	607,161
Selling, general and administrative expense	311,817	344,361	481,183	468,042
Amortization expense	92,863	98,671	104,943	131,562
Income from operations	49,077	21,764	39,953	7,557
Other (expense) income	1,425	1,882	(23,506)	2,236
Interest expense	73,742	70,285	97,782	94,660
Loss before income taxes	(23,240)	(46,639)	(81,335)	(84,867)
Income tax benefit	9,285	17,769	66,248	32,503
Net loss	$ (13,955)	$ (28,870)	$ (15,087)	$ (52,364)
Loss per share:
Basic and Diluted	$ (0.18)	$ (0.37)	$ (0.18)	$ (0.67)