Net Income Per Common Share - Basic and Diluted Net Income Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Basic
Net income applicable to common stock	$ 2,008	$ 45,110
Average common shares outstanding (shares)	56,534,816	58,585,517
Net income per common share - basic (usd per share)	$ 0.04	$ 0.77
Diluted
Net income applicable to common stock	$ 2,008	$ 45,110
Average common shares outstanding (shares)	56,534,816	58,585,517
Effect of dilutive stock-based compensation (shares)	171,473	145,018
Average common shares outstanding - diluted (shares)	56,706,289	58,730,535
Net income per common share - diluted (usd per share)	$ 0.04	$ 0.77