Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
DEFERRED TAX ASSETS:
Accounting reserves and accruals	$ 14,594	$ 14,830
Defined benefit plan	4,620	4,148
Deferred management rights proceeds	44,189	44,651
Federal and State net operating loss carryforwards	59,382	44,789
Tax credits and other carryforwards	870	640
Investment in joint ventures		317
Other assets	4,427	4,353
Total deferred tax assets	128,082	113,728
Valuation allowance	(14,210)	(14,616)
Total deferred tax assets, net of valuation allowance	113,872	99,112
DEFERRED TAX LIABILITIES:
Property and equipment, net	57,931	47,416
Investment in joint ventures	14,135
Goodwill and other intangibles	478	705
Other liabilities	771	874
Total deferred tax liabilities	73,315	48,995
Net deferred tax assets	$ 40,557	$ 50,117