Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Net income available to common stockholders	$ 42,424	$ 16,996	$ (7,640)	$ 36,173	$ 14,805	$ (762)	$ 51,780	$ 50,216
Weighted average common shares outstanding, basic (in shares)	48,141			48,070			48,121	48,058
Weighed average common shares outstanding, dilutive (in shares)	48,141			48,070			48,121	48,058
Earnings per share - basic (in dollars per share)	$ 0.88			$ 0.75			$ 1.08	$ 1.04
Earnings per share - diluted (in dollars per share)	$ 0.88			$ 0.75			$ 1.08	$ 1.04