Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
DEFERRED TAX ASSETS:
Accounting reserves and accruals	$ 17,545	$ 15,931
Defined benefit plan	3,924	4,194
Deferred management rights proceeds	42,424	43,420
Federal and State net operating loss carryforwards	110,869	45,794
Tax credits and other carryforwards	1,114	499
Other assets	5,022	4,605
Net deferred tax assets		25,959
Total deferred tax assets	180,898	114,443
Valuation allowance	(97,700)	(12,387)
Total deferred tax assets, net of valuation allowance	83,198	102,056
DEFERRED TAX LIABILITIES:
Property and equipment, net	70,856	61,970
Investment in joint ventures	11,048	12,639
Intangibles	1,084	717
Other liabilities	875	771
Total deferred tax liabilities	83,863	76,097
Net deferred tax liabilities	$ (665)
Deferred income tax assets, net		$ 25,959