Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator:
Net income (loss) attributable to common shareholders	$ 52,234	$ 54,079	$ 49,730	$ 74,465
Less: dividends paid on unvested share-based compensation	(74)	(83)	(147)	(166)
Undistributed earnings attributable to share-based compensation	(3)	(88)	0	(69)
Net income (loss) available to common shareholders	$ 52,157	$ 53,908	$ 49,583	$ 74,230
Denominator:
Weighted-average number of common shares — basic (in shares)	130,484,956	68,912,185	130,458,164	68,894,413
Effect of dilutive share-based compensation (in shares)	110,898	292,386	204,243	332,685
Weighted-average number of common shares — diluted (in shares)	130,595,854	69,204,571	130,662,407	69,227,098
Net income (loss) per share available to common shareholders — basic (in usd per share)	$ 0.40	$ 0.78	$ 0.38	$ 1.08
Net income (loss) per share available to common shareholders — diluted (in usd per share)	$ 0.40	$ 0.78	$ 0.38	$ 1.07
Antidilutive securities excluded from computation of earnings per share (in shares)	163,100	83,130	37,137	4,212