Net Income Per Common Share - Basic and Diluted Net Income Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Basic
Net income applicable to common stock	$ 40,867	$ 20,130	$ 98,775	$ 22,138
Average common shares outstanding (shares)	56,325,717	56,165,452	56,283,195	56,350,134
Net income per common share - basic (usd per share)	$ 0.73	$ 0.36	$ 1.75	$ 0.39
Diluted
Net income applicable to common stock	$ 40,867	$ 20,130	$ 98,775	$ 22,138
Average common shares outstanding (shares)	56,325,717	56,165,452	56,283,195	56,350,134
Effect of dilutive stock-based compensation (shares)	310,181	160,024	295,385	164,465
Average common shares outstanding - diluted (shares)	56,635,898	56,325,476	56,578,580	56,514,599
Net income per common share - diluted (usd per share)	$ 0.72	$ 0.36	$ 1.75	$ 0.39