Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
BASIC
Net income attributable to common shareholders	$ 141,560	$ 216,190	$ 189,657	$ 197,010
Weighted-average number of common shares outstanding - basic	236,285,216	237,354,669	233,833,340	237,577,198
Income (loss) per common share:
Net income (loss) attributable to common shares outstanding - basic (in dollars per share)	$ 0.60	$ 0.91	$ 0.81	$ 0.83
DILUTED
Impact of assumed conversions	$ 1,573	$ 4,159	$ 0	$ 2,505
Net income attributable to common shareholders	$ 143,133	$ 220,349	$ 189,657	$ 199,515
Effect of dilutive securities:
Unvested share-based payment awards (in shares)	359,503	382,956	178,303	463,922
Preferred shares - Series C (in shares)	4,710,570	4,710,570	0	0
OP Units (in shares)	0	3,610,103	0	3,619,468
Weighted-average common shares outstanding - diluted (in shares)	241,355,289	246,058,298	234,011,643	241,660,588
Net income (loss) attributable to common shareholders - per common share diluted (in dollars per share)	$ 0.59	$ 0.90	$ 0.81	$ 0.83