Accounting Policies - Summary of Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic earnings per share
Net income	$ 20,312	$ 20,537	$ 46,606	$ 47,995
Weighted average common shares outstanding (in shares)	43,862,435	45,038,021	44,099,862	42,995,082
Basic Earnings Per Share (in USD per share)	$ 0.46	$ 0.46	$ 1.06	$ 1.12
Diluted earnings per share
Net income	$ 20,312	$ 20,537	$ 46,606	$ 47,995
Effect of dilutive securities:
Weighted average common shares outstanding (in shares)	43,903,881	45,113,730	44,165,650	43,070,095
Diluted Earnings Per Share (in USD per share)	$ 0.46	$ 0.46	$ 1.06	$ 1.11
Restricted Stock
Effect of dilutive securities:
Effect of dilutive securities	8,246	0	32,574	0
Stock Options
Effect of dilutive securities:
Effect of dilutive securities	33,200	75,709	33,214	75,013