Earnings Per Common Share - Schedule of Computation (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Class of Stock [Line Items]
Net income attributable to common stockholders	$ 108,087	$ 130,418	$ 307,685	$ 313,827
Earnings and dividends allocated to participating securities	(165)	(219)	(508)	(550)
Earnings for basic computations	107,922	130,199	307,177	313,277
Earnings and dividends allocated to participating securities	165	0	0	550
Income allocated to noncontrolling interest - Preferred Operating Partnership Units and Operating Partnership Units	6,100	7,336	17,539	17,191
Fixed component of income allocated to noncontrolling interest - Preferred Operating Partnership (Series A Units)	(572)	(572)	(1,716)	(1,716)
Net income for diluted computations	$ 113,615	$ 136,963	$ 323,000	$ 329,302
Weighted average common shares outstanding:
Average number of common shares outstanding - basic (in shares)	128,776,549	126,466,837	127,830,272	125,959,926
OP Units (in shares)	6,050,028	5,636,845	6,032,656	5,650,599
Unvested restricted stock awards included for treasury stock method (in shares)	209,963	0	0	250,630
Shares related to exchangeable senior notes and dilutive stock options (in shares)	1,406,455	269,390	1,425,891	279,055
Average number of common shares outstanding - diluted (in shares)	137,318,475	134,240,290	136,164,299	133,015,690
Earnings per common share
Basic (in dollars per share)	$ 0.84	$ 1.03	$ 2.40	$ 2.49
Diluted (in dollars per share)	$ 0.83	$ 1.02	$ 2.37	$ 2.48
Series A Units
Weighted average common shares outstanding:
Preferred series units (in shares)	875,480	875,480	875,480	875,480
Series D Units
Weighted average common shares outstanding:
Preferred series units (in shares)	0	991,738	0	0