Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Redemption of units for stock Series D Units	Redemption of units for cash	Redemption of units for cash Series B Units	Preferred Operating Partnership	Preferred Operating Partnership Redemption of units for stock Series D Units	Preferred Operating Partnership Redemption of units for cash Series B Units	Operating Partnership	Operating Partnership Redemption of units for stock	Operating Partnership Redemption of units for cash	Other	Common Stock	Common Stock Redemption of units for stock	Common Stock Redemption of units for stock Series D Units	Additional Paid-in Capital	Additional Paid-in Capital Redemption of units for stock	Additional Paid-in Capital Redemption of units for stock Series D Units	Additional Paid-in Capital Redemption of units for cash	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance at Dec. 31, 2017	$ 2,723,807				$ 159,636			$ 213,301			$ 119	$ 1,260			$ 2,569,485				$ 33,290	$ (253,284)
Beginning balance (in shares) at Dec. 31, 2017												126,007,091
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon the exercise of options	$ 1,169														1,169
Issuance of common stock upon the exercise of options (in shares)	54,575											54,575
Restricted stock grants issued	$ 1											$ 1
Restricted stock grants issued (in shares)												85,066
Restricted stock grants cancelled (in shares)												(11,771)
Issuance of common stock, net of offering costs	90,231											$ 10			90,221
Issuance of common stock, net of offering costs (in shares)												933,789
Compensation expense related to stock-based awards	11,176														11,176
Repayment of receivable for preferred operating units pledged as collateral on loan	495				495
Issuance of Operating Partnership units in conjunction with acquisitions	1,877							1,877
Redemption of noncontrolling interests	0		$ (2,558)						$ (1,337)	$ (1,126)						$ 1,337		$ (1,432)
Redemption of noncontrolling interests (in shares)													35,000
Conversion of Preferred C Units in the Operating Partnership for Common Operating Partnership Units	0				(6,851)			6,851
Noncontrolling interest in consolidated joint venture	122										122
Repurchase of equity portion of 2013 exchangeable senior notes	(31,251)														(31,251)
Net income (loss)	447,080				13,995			17,797			(1)									415,289
Other comprehensive income (loss)	1,430				12			58											1,360
Distributions to Operating Partnership units held by noncontrolling interests	(33,250)				(14,191)			(19,059)
Dividends paid on common stock	(424,907)																			(424,907)
Ending balance at Dec. 31, 2018	2,785,422				153,096			218,362			240	$ 1,271			2,640,705				34,650	(262,902)
Ending balance (in shares) at Dec. 31, 2018												127,103,750
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon the exercise of options	$ 3,063											$ 3			3,060
Issuance of common stock upon the exercise of options (in shares)	211,057											211,057
Restricted stock grants issued	$ 2											$ 2
Restricted stock grants issued (in shares)												109,081
Restricted stock grants cancelled (in shares)												(8,863)
Issuance of common stock, net of offering costs	198,827											$ 19			198,808
Issuance of common stock, net of offering costs (in shares)												1,779,200
Compensation expense related to stock-based awards	13,051														13,051
Repayment of receivable for preferred operating units pledged as collateral on loan	1,211							1,211
Issuance of Operating Partnership units in conjunction with acquisitions	28,022				28,022
Redemption of noncontrolling interests	0								(13,057)							13,057
Redemption of noncontrolling interests (in shares)													340,182
Conversion of Preferred C Units in the Operating Partnership for Common Operating Partnership Units	0				(4,374)			4,374
Noncontrolling interest in consolidated joint venture	173										173
Net income (loss)	451,123				12,492			18,711			(47)									419,967
Other comprehensive income (loss)	(66,843)				(407)			(2,820)											(63,616)
Distributions to Operating Partnership units held by noncontrolling interests	(34,243)				(12,881)			(21,362)
Dividends paid on common stock	(458,114)																			(458,114)
Ending balance at Dec. 31, 2019	$ 2,921,694				175,948			205,419			366	$ 1,295			2,868,681				(28,966)	(301,049)
Ending balance (in shares) at Dec. 31, 2019	129,534,407											129,534,407
Increase (Decrease) in Stockholders' Equity
Issuance of common stock upon the exercise of options	$ 4,759											$ 1			4,758
Issuance of common stock upon the exercise of options (in shares)	134,930											134,930
Issuance of common stock in connection with share based compensation (in shares)												143,187
Issuance of common stock in connection with share based compensation	$ 16,281											$ 1			16,280
Restricted stock grants cancelled (in shares)												(5,083)
Issuance of common stock, net of offering costs	103,468											$ 9			103,459
Issuance of common stock, net of offering costs (in shares)												899,048
Buyback of common stock, net of offering costs	(67,873)											$ (8)								(67,865)
Buyback of common stock, net of offering costs (in shares)												(826,797)
Repayment of receivable for preferred operating units pledged as collateral on loan	16,213							16,213
Redemption of noncontrolling interests	0	$ 0		$ (1,000)		$ (2,724)	$ (1,000)		$ (4,572)				$ 1	$ 1		4,571	$ 2,723
Redemption of noncontrolling interests (in shares)				40,000									123,993	30,495
Repurchase of equity portion of 2015 exchangeable senior notes	0												$ 14			$ (14)
Repurchase of equity portion of 2015 exchangeable senior notes (in shares)													1,323,781
Noncontrolling interest in consolidated joint venture	66										66
Net income (loss)	517,582				12,882			22,952			(31)									481,779
Other comprehensive income (loss)	(73,686)				(456)			(3,103)											(70,127)
Distributions to Operating Partnership units held by noncontrolling interests	(33,615)				(12,598)			(21,017)
Dividends paid on common stock	(467,765)																			(467,765)
Ending balance at Dec. 31, 2020	$ 2,936,124				$ 172,052			$ 215,892			$ 401	$ 1,314			$ 3,000,458				$ (99,093)	$ (354,900)
Ending balance (in shares) at Dec. 31, 2020	131,357,961											131,357,961