Impact of Recent Accounting Pronouncements (Additional Information) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses	$ 75,143	$ 55,525	$ 55,525	$ 55,353	$ 55,562
Provision for credit losses for off-balance sheet credit exposure		0
Retained earnings	$ 686,397		$ 695,273
Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		7,900
Provision for credit losses for off-balance sheet credit exposure		3,200
Retained earnings		8,300
Construction | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		$ 1,300