Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator:
Net income attributable to common shareholders	$ 13,387	$ 5,034	$ 16,233	$ 9,647
Dividends paid on unvested shares and units	(85)	(65)	(170)	(127)
Undistributed earnings allocated to unvested shares and units	0	0	0	0
Net income attributable to common shareholders	$ 13,302	$ 4,969	$ 16,063	$ 9,520
Denominator:
Weighted average number of common shares - basic (in shares)	45,867,625	38,525,306	45,811,023	38,443,663
Unvested shares (in shares)	217,063	224,355	195,538	215,526
Weighted average number of common shares - diluted (in shares)	46,084,688	38,749,661	46,006,561	38,659,189
Basic income per Common Share:
Net income attributable to common shareholders per weighted average basic common share (in dollars per share)	$ 0.29	$ 0.13	$ 0.35	$ 0.25
Diluted income per Common Share:
Net income attributable to common shareholders per weighted average diluted common share (in dollars per share)	$ 0.29	$ 0.13	$ 0.35	$ 0.25