Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net Income
Net income	$ 16,739	$ 10,467	$ 47,452	$ 34,355
Dividends on preferred stock	(833)	(833)	(2,498)	(2,497)
Net Income Allocated to Common Shareholders	$ 15,906	$ 9,634	$ 44,954	$ 31,858
Weighted-Average Shares
Weighted average shares - Basic	28,694,036	21,310,199	28,692,591	21,180,384
Effect of dilutive securities-restricted stock awards	33,786	18,038	27,149	13,473
Weighted average shares - diluted	28,727,822	21,328,237	28,719,740	21,193,857
Per Share Amount
Basic earnings per share	$ 0.55	$ 0.45	$ 1.57	$ 1.50
Diluted earnings per share	$ 0.55	$ 0.45	$ 1.57	$ 1.50