Investments in Unconsolidated Funds - Selected Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Balance Sheet
Total assets	$ 9,313,054		$ 9,349,301
Total liabilities	5,183,347		4,978,367
Total equity	2,541,762		2,712,072
Statement of Operations
Total revenues	251,350	$ 224,186
Operating income	64,218	63,477
Net income	26,923	28,701
Unconsolidated Funds
Balance Sheet
Total assets	135,547		136,479
Total liabilities	114,056		113,330
Total equity	21,491		$ 23,149
Statement of Operations
Total revenues	4,602	20,159
Operating income	1,522	5,395
Net income	$ 886	$ 1,332