Co-investments - Combined Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Equity Method Investment, Summarized Financial Information, Assets [Abstract] (Deprecated 2020-01-31)
Rental properties and real estate under development	$ 364,875		$ 364,875			$ 546,075
Total assets	13,401,042		13,401,042			12,705,405
Debt	7,102,841		7,102,841			6,264,491
Other liabilities	39,636		39,636			36,565
Cumulative effect upon adoption of ASU No. 2016-13	6,267,482	$ 6,415,004	6,267,482	$ 6,415,004	$ 6,352,881	6,403,504	$ 6,345,116	$ 6,393,844
Total liabilities and equity	13,401,042		13,401,042			12,705,405
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract] (Deprecated 2020-01-31)
Property revenues	370,811	366,932	1,133,675	1,084,790
Interest expense	(55,430)	(54,896)	(165,024)	(162,651)
General and administrative	(13,310)	(11,345)	(42,244)	(38,731)
Net income	78,842	105,700	497,683	329,266
Total co-investment | Affiliated Entity
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract] (Deprecated 2020-01-31)
Company's share of net income	2,200	2,000	6,400	5,500
Equity Method Investment, Nonconsolidated Investee or Group of Investees | Total co-investment
Equity Method Investment, Summarized Financial Information, Assets [Abstract] (Deprecated 2020-01-31)
Rental properties and real estate under development	4,391,064		4,391,064			4,733,762
Other assets	216,357		216,357			139,562
Total assets	4,607,421		4,607,421			4,873,324
Debt	2,692,418		2,692,418			2,442,213
Other liabilities	179,121		179,121			117,160
Cumulative effect upon adoption of ASU No. 2016-13	1,735,882		1,735,882			2,313,951
Total liabilities and equity	4,607,421		4,607,421			4,873,324
Company's share of equity	1,018,235		1,018,235			$ 1,335,339
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract] (Deprecated 2020-01-31)
Property revenues	76,581	84,071	226,125	249,628
Property operating expenses	(28,047)	(29,214)	(79,621)	(85,768)
Net operating income	48,534	54,857	146,504	163,860
Interest expense	(19,369)	(16,089)	(59,700)	(47,284)
General and administrative	(5,161)	(2,603)	(12,636)	(6,774)
Depreciation and amortization	(29,732)	(30,411)	(86,947)	(89,283)
Net income	(5,728)	5,754	(12,779)	20,519
Company's share of net income	$ 14,960	$ 21,700	$ 53,514	$ 54,935