Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Statutory rate applied to pre-tax (loss) income from continuing operations	$ (246,495)	$ 7,202	$ (57,589)
Effective Income Tax Rate Reconciliation, Amount [Abstract]
State income taxes, net of federal benefit	(913)	21	(1,273)
Foreign	53	442	287
Revaluation of contingent purchase price	(5,366)	(10,244)	10,272
Tax credits	(3,539)	(967)	(305)
Lobbying costs	0	0	35
Meals and entertainment	372	605	810
Uncertain tax positions	(1,635)	(2,064)	61
Bargain purchase	0	0	(7,310)
Loss on extinguishment of debt	0	1,403	0
Loss on ACC goodwill	0	11,834	0
Excess stock option benefit	(4,589)	0	0
Change in federal tax rate due to the Tax Cuts and Jobs Act	126,502	0	0
Other	785	(485)	1,239
Tax benefit of operating loss carryforwards	11,509	(105,045)	0
Valuation allowances	26,740	97,365	24,040
Income tax benefit	$ (96,576)	$ 67	$ (29,733)