Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Rental income		$ 1,443,360	$ 1,588,400	$ 1,380,422
Total revenues		4,605,967	5,121,306	4,700,499
Expenses:
Property operating expenses		2,597,823	2,690,042	2,433,017
Depreciation and amortization		1,038,437	1,027,073	950,459
Interest expense		514,388	555,559	526,592
General and administrative expenses		128,394	126,549	126,383
Loss (gain) on derivatives and financial instruments, net		11,049	(4,399)	(4,016)
Loss (gain) on extinguishment of debt, net		47,049	84,155	16,097
Provision for loan losses		94,436	18,690	0
Impairment of assets		135,608	28,133	115,579
Other expenses		70,335	52,612	112,898
Total expenses		4,637,519	4,578,414	4,277,009
Income (loss) from continuing operations before income taxes and other items		(31,552)	542,892	423,490
Income tax (expense) benefit		(9,968)	(2,957)	(8,674)
Income (loss) from unconsolidated entities		(8,083)	42,434	(641)
Gain (loss) on real estate dispositions, net		1,088,455	748,041	415,575
Income (loss) from continuing operations		1,038,852	1,330,410	829,750
Net income		1,038,852	1,330,410	829,750
Less:  Preferred stock dividends		0	0	46,704
Less: Net income (loss) attributable to noncontrolling interests	[1]	60,008	97,978	24,796
Net income (loss) attributable to common stockholders		$ 978,844	$ 1,232,432	$ 758,250
Average number of common shares outstanding:
Basic (in shares)		415,451	401,845	373,620
Diluted (in shares)		417,387	403,808	375,250
Basic:
Income (loss) from continuing operations (in USD per share)		$ 2.50	$ 3.31	$ 2.22
Net income (loss) attributable to common stockholders (in USD per share)		2.36	3.07	2.03
Diluted:
Income (loss) from continuing operations (in USD per share)		2.49	3.29	2.21
Net income (loss) attributable to common stockholders (in USD per share)	[2]	$ 2.33	$ 3.05	$ 2.02
Resident fees and services
Revenues:
Revenue from contract with customer		$ 3,074,022	$ 3,448,175	$ 3,234,852
Interest income
Revenues:
Revenue from contract with customer		69,156	63,830	55,814
Other income
Revenues:
Revenue from contract with customer		$ 19,429	$ 20,901	$ 29,411

[1] Includes amounts attributable to redeemable noncontrolling interests

[2] Includes adjustment to the numerator for income (loss) attributable to OP unitholders