Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
BASIC
Net income attributable to common shareholders	$ 216,190	$ 3,916	$ 197,010	$ 49,832
Weighted-average number of common shares outstanding - basic	237,354,669	237,989,098	237,577,198	237,632,572
Income (loss) per common share:
Net income (loss) attributable to common shares outstanding - basic (in dollars per share)	$ 0.91	$ 0.02	$ 0.83	$ 0.21
DILUTED
Impact of assumed conversions	$ 4,159	$ (173)	$ 2,505	$ (192)
Net income attributable to common shareholders	$ 220,349	$ 3,743	$ 199,515	$ 49,640
Effect of dilutive securities:
Unvested share-based payment awards (in shares)	382,956	66,748	463,922	95,788
Preferred shares - Series C (in shares)	4,710,570	0	0	0
OP Units (in shares)	3,610,103	3,646,869	3,619,468	3,713,867
Weighted-average common shares outstanding (in shares)	246,058,298	241,702,715	241,660,588	241,442,227
Net income (loss) attributable to common shareholders - per common share diluted (in dollars per share)	$ 0.90	$ 0.02	$ 0.83	$ 0.21