Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Weighted average number of stock options excluded (in shares)									0	17,524	82,760
Income/(Loss) (numerator)
Net income applicable to earnings per share									$ 123,340	$ 60,100	$ 40,103
Basic earnings per share: Income available to common stockholders	$ 39,643	$ 28,392	$ 27,303	$ 28,002	$ 16,171	$ 20,232	$ 14,176	$ 9,521	123,340	60,100	40,103
Diluted earnings per share: Income available to common stockholders									$ 123,340	$ 60,100	$ 40,103
Shares (denominator)
Basic earnings per share: Income available to common stockholders (in shares)									53,963,047	37,705,556	26,931,634
Effect of dilutive securities: Warrants and stock option plans (in shares)									650,010	805,705	507,525
Diluted earnings per share: Income available to common stockholders (in shares)									54,613,057	38,511,261	27,439,159
Per Share Amount
Basic earnings per share: Income available to common stockholders (in dollars per share)	$ 0.64	$ 0.46	$ 0.59	$ 0.61	$ 0.37	$ 0.46	$ 0.36	$ 0.35	$ 2.29	$ 1.59	$ 1.49
Diluted earnings per share: Income available to common stockholders (in dollars per share)	$ 0.63	$ 0.46	$ 0.58	$ 0.60	$ 0.36	$ 0.46	$ 0.35	$ 0.34	$ 2.26	$ 1.56	$ 1.46