Income Taxes - Schedule of Reconciliation between Statutory Income Tax Rate and Company's Effective Income Tax Provision (Benefit) Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Income tax at federal statutory rates	21.00%	35.00%	35.00%
Federal net operating loss adjustment			(13.18%)
State taxes, net of federal benefit	7.40%	2.02%	(58.42%)
Nondeductible equity-based compensation	1.07%	(1.01%)	(275.10%)
Tax credits	(1.95%)	0.25%	58.75%
Goodwill impairment		(6.12%)
Remeasurement of deferred income tax liabilities resulting from Tax Cuts and Jobs Act		0.63%
Nondeductible settlement	1.34%
Valuation allowance		(0.59%)	27.55%
Other	(0.29%)	(0.60%)	(66.07%)
Income tax provision (benefit) rate	28.57%	29.58%	(291.47%)
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax at federal statutory rates	$ 13,167	$ (100,587)	$ (1,120)
Federal net operating loss adjustment			(422)
State taxes, net of federal benefit	4,640	(5,800)	1,870
Nondeductible equity-based compensation	668	2,901	8,806
Tax credits	(1,221)	(730)	(1,881)
Goodwill impairment		17,584
Remeasurement of deferred income tax liabilities resulting from Tax Cuts and Jobs Act		(1,808)
Nondeductible settlement	840
Valuation allowance		1,688	(882)
Other	(179)	1,746	2,115
Total income tax provision (benefit)	$ 17,915	$ (85,006)	$ 9,330