Earnings per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	40,111
Numerator:
Net income (loss) attributable to common shareholders	$ 20,004	$ 16,591	$ 20,659	$ 14,588
Less: dividends paid on unvested share-based compensation	(107)	(125)	(215)	(250)
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	0	(14)	0	0
Net income (loss) available to common shareholders	$ 19,897	$ 16,452	$ 20,444	$ 14,338
Denominator:
Weighted-average number of common shares-basic	71,735,129	63,764,929	71,696,294	63,763,935
Effect of dilutive share-based compensation	690,823	360,128	767,125	386,331
Weighted-average number of common shares-diluted	72,425,952	64,125,057	72,463,419	64,150,266
Net income (loss) per share available to common shareholders-basic (in dollars per share)	$ 0.28	$ 0.26	$ 0.29	$ 0.22
Net income (loss) per share available to common shareholders-diluted (usd per share)	$ 0.27	$ 0.26	$ 0.28	$ 0.22