Summary of Significant Accounting Policies - Schedule of Computation of Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Net income attributable to common stockholders	$ 112,282	$ 108,087	$ 104,828	$ 94,770	$ 101,462	$ 130,418	$ 95,153	$ 88,256	$ 419,967	$ 415,289	$ 479,013
Earnings and dividends allocated to participating securities									(680)	(723)	(975)
Earnings for basic computations									419,287	414,566	478,038
Earnings and dividends allocated to participating securities									680	723	0
Income allocated to noncontrolling interest - Preferred Operating Partnership Units and Operating Partnership Units									23,727	22,831	30,088
Fixed component of income allocated to noncontrolling interest - Preferred Operating Partnership (Series A Units)									(2,288)	(2,288)	(3,119)
Net income for diluted computations									$ 441,406	$ 435,832	$ 505,007
Weighted average common shares outstanding:
Average number of common shares outstanding - basic (in shares)									128,203,568	126,087,487	125,967,831
OP Units (in shares)									6,006,114	5,675,547	5,590,831
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Unvested restricted stock awards included for treasury stock method (in shares)									212,402	244,215	0
Shares related to exchangeable senior notes and dilutive stock options (in shares)									1,136,205	276,304	640,068
Average number of common shares outstanding - diluted (in shares)									136,433,769	133,159,033	134,155,771
Earnings per common share
Basic (in dollars per share)	$ 0.87	$ 0.84	$ 0.82	$ 0.74	$ 0.80	$ 1.03	$ 0.75	$ 0.70	$ 3.27	$ 3.29	$ 3.79
Diluted (in dollars per share)	$ 0.86	$ 0.83	$ 0.81	$ 0.74	$ 0.80	$ 1.02	$ 0.75	$ 0.70	$ 3.24	$ 3.27	$ 3.76
Series A Units
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Series A&D Units (in shares)									875,480	875,480	875,480
Series D Units
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Series A&D Units (in shares)									0	0	1,081,561