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
Numerator:
Net income (loss) attributable to common shareholders	$ 21,752	$ 25,769	$ 71,482	$ 100,234
Less: dividends paid on unvested share-based compensation	(74)	(83)	(220)	(249)
Undistributed earnings attributable to share-based compensation	0	0	0	(67)
Net income (loss) available to common shareholders	$ 21,678	$ 25,686	$ 71,262	$ 99,918
Denominator:
Weighted-average number of common shares — basic (in shares)	130,484,956	68,912,185	130,467,193	68,900,402
Effect of dilutive share-based compensation (in shares)	137,174	343,673	223,149	366,696
Weighted-average number of common shares — diluted (in shares)	130,622,130	69,255,858	130,690,342	69,267,098
Net income (loss) per share available to common shareholders — basic (in usd per share)	$ 0.17	$ 0.37	$ 0.55	$ 1.45
Net income (loss) per share available to common shareholders — diluted (in usd per share)	$ 0.17	$ 0.37	$ 0.55	$ 1.44
Antidilutive securities excluded from computation of earnings per share (in shares)	128,563	0	37,137	4,212