REAL ESTATE OWNED (UNITED DOMINION REALTY, L.P.) - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Real estate owned
Land	$ 2,163,055	$ 2,164,032
Depreciable property - held and used:
Land improvements	225,850	224,964
Building, improvements, and furniture, fixtures and equipment	10,178,547	10,102,758
Real estate owned	12,817,998	12,602,101
Accumulated depreciation	(4,272,471)	(4,131,353)
Total real estate owned, net of accumulated depreciation	8,545,527	8,470,748
United Dominion Realty L.P.
Real estate owned
Land	711,256	711,256
Depreciable property - held and used:
Land improvements	97,807	96,864
Building, improvements, and furniture, fixtures and equipment	3,077,550	3,067,040
Real estate owned	3,886,613	3,875,160
Accumulated depreciation	(1,831,814)	(1,796,568)
Total real estate owned, net of accumulated depreciation	$ 2,054,799	$ 2,078,592