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, 2021	Mar. 31, 2020
Basic
Net income applicable to common stock	$ 57,908	$ 2,008
Average common shares outstanding (shares)	56,240,201	56,534,816
Net income per common share - basic (usd per share)	$ 1.03	$ 0.04
Diluted
Net income applicable to common stock	$ 57,908	$ 2,008
Average common shares outstanding (shares)	56,240,201	56,534,816
Effect of dilutive stock-based compensation (shares)	278,998	171,473
Average common shares outstanding - diluted (shares)	56,519,199	56,706,289
Net income per common share - diluted (usd per share)	$ 1.02	$ 0.04