Income Taxes - Reconciliation of Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax at statutory rate	$ 22,899	$ 28,150	$ 24,432
State taxes, net of federal benefit	6,450	3,548	2,010
Effect of U.S. tax reform (the Tax Act)	0	13,074	0
Effect of net income (loss) attributable to noncontrolling interests	(171)	(1,017)	(91)
Change in valuation allowance	4,508	(2,613)	(5,125)
Other, net	(725)	(652)	(182)
Income tax expense (benefit)	$ 32,961	$ 40,490	$ 21,044
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Tax at statutory rate	21.00%	35.00%	35.00%
State taxes, net of federal benefit	6.00%	4.00%	3.00%
Effect of U.S. tax reform (the Tax Act)	0.00%	16.00%	0.00%
Effect of net income (loss) attributable to noncontrolling interests	(0.00%)	(1.00%)	(0.00%)
Change in valuation allowance	4.00%	(3.00%)	(7.00%)
Other, net	(1.00%)	(1.00%)	(1.00%)
Income tax expense (benefit)	30.00%	50.00%	30.00%