- Earnings Per 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
BASIC
Net income attributable to common shareholders	$ 83,574	$ 141,560	$ 21,721	$ 26,405	$ 23,796	$ 216,190	$ (3,327)	$ (15,957)	$ 273,225	$ 220,838	$ 79,067
Weighted-average common shares outstanding - basic (in shares)									237,642,048	236,666,375	237,758,408
Net income attributable to common shareholders - basic (usd per share)	$ 0.34	$ 0.60	$ 0.09	$ 0.11	$ 0.10	$ 0.91	$ (0.01)	$ (0.07)	$ 1.15	$ 0.93	$ 0.33
DILUTED:
Impact of assumed conversions									$ 0	$ 2,528	$ 147
Net income attributable to common shareholders									$ 273,225	$ 223,366	$ 79,214
Weighted-average common shares outstanding - basic (in shares)									237,642,048	236,666,375	237,758,408
Effect of dilutive securities:
Unvested share-based payment awards and options (in shares)									292,467	528,495	86,285
Operating Partnership Units (in shares)									0	3,616,120	3,693,144
Weighted-average common shares outstanding (in shares)									237,934,515	240,810,990	241,537,837
Net income (loss) attributable to common shareholders - per common share diluted (usd per share)	$ 0.33	$ 0.59	$ 0.09	$ 0.11	$ 0.10	$ 0.90	$ (0.01)	$ (0.07)	$ 1.15	$ 0.93	$ 0.33