Schedule III - Real Estate and Accumulated Depreciation and Amortization - Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Abstract]
Total cost basis for federal income tax purposes	$ 4,200,000
Reconciliation of real estate owned:
Balance at the beginning of year	3,514,564	$ 3,320,574	$ 3,090,134
Additions during year	860,311	580,861	663,742
Properties sold and impaired during the year	(653,247)	(354,218)	(496,730)
Other reclassifications	(137,650)	(32,653)	63,428
Balance at end of year	3,583,978	3,514,564	3,320,574
Reconciliation of accumulated depreciation and amortization:
Balance at the beginning of year	684,468	675,596	722,644
Depreciation and amortization expense	138,879	127,504	118,525
Accumulated depreciation and amortization of properties sold, impaired and held for sale during year	(244,751)	(102,261)	(177,709)
Other reclassifications	(73,897)	(16,371)	12,136
Balance at end of year	$ 504,699	$ 684,468	$ 675,596