Income Taxes - Components of Deferred Tax Liabilities and Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax liabilities:
Real estate and real estate partnership basis differences	$ 12,058	$ 32,032
Deferred tax assets:
Net operating, capital and other loss carryforwards	7,022	9,523
Accruals and expenses	7,432	6,575
Tax credit carryforwards	67,530	73,450
Management contracts and other	2,064	200
Total deferred tax assets	84,048	89,748
Valuation allowance	(4,930)	(25,489)
Net deferred tax assets	$ 67,060	$ 32,227