Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Net income available to common stockholders	$ 13,022	$ 18,531	$ 10,477	$ 19,663
Weighted average common shares outstanding, basic (in shares)	48,073	48,020	48,051	48,002
Weighed average common shares outstanding, dilutive (in shares)	48,073	48,020	48,051	48,002
Earnings per share - basic (in dollars per share)	$ 0.27	$ 0.39	$ 0.22	$ 0.41
Earnings per share - diluted (in dollars per share)	$ 0.27	$ 0.39	$ 0.22	$ 0.41