Condensed Parent Company Information - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows From Operating Activities
Net income	$ 81,477	$ 92,046	$ 89,289
Decrease (increase) in other assets	(991)	(3,171)	6,059
Increase (decrease) in other liabilities	9,805	(391)	(8,230)
Net cash provided by operating activities	57,075	51,238	46,410
Cash Flows From Financing Activities
Repurchases of common stock	(31,868)	(10,000)	0
Stock withheld for payment of taxes	(307)	(702)	(406)
Net cash provided by financing activities	1,039,194	141,852	240,277
Increase (decrease) in Cash and Cash Equivalents	135,988	(231,596)	(26,592)
Cash and Cash Equivalents, Beginning of Year	231,302	462,898	489,490
Cash and Cash Equivalents, End of Year	367,290	231,302	462,898
Parent Company
Cash Flows From Operating Activities
Net income	81,477	92,046	89,289
Equity in undistributed earnings of subsidiaries	(20,899)	(65,555)	(77,050)
Decrease (increase) in other assets	5,806	(5,850)	(13)
Increase (decrease) in other liabilities	(3)	64	146
Net cash provided by operating activities	66,381	20,705	12,372
Cash Flows From Financing Activities
Payment of common stock cash dividends	(20,936)	(13,662)	(11,281)
Repurchases of common stock	(31,868)	(10,000)	0
Proceeds from issuance of common stock	0	129	324
Stock withheld for payment of taxes	(307)	(702)	(406)
Net cash provided by financing activities	(53,111)	(24,235)	(11,363)
Increase (decrease) in Cash and Cash Equivalents	13,270	(3,530)	1,009
Cash and Cash Equivalents, Beginning of Year	2,014	5,544	4,535
Cash and Cash Equivalents, End of Year	$ 15,284	$ 2,014	$ 5,544