Condensed Financial Information (parent company only) - Statements of Income and Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income
Other income	$ 3,008	$ 1,898	$ 2,068
Expenses
Interest expense	35,952	66,381	108,745
Salaries and employee benefits	166,995	155,937	144,037
Other expenses	19,300	18,001	17,804
Income tax benefit	(35,259)	(21,375)	(29,325)
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	205,531	148,600	164,460
Net income	205,531	148,600	164,460
Other comprehensive income (loss)	(19,723)	46,962	49,296
Comprehensive income	185,808	195,562	213,756
Parent
Income
Dividends from subsidiaries	161,825	70,100	125,775
Other income	(50)	(62)	172
Total income	161,775	70,038	125,947
Expenses
Interest expense	6,642	6,777	8,309
Salaries and employee benefits	3,917	3,426	3,540
Net occupancy and equipment expenses	825	745	802
Other outside services	1,001	731	1,889
Professional services	263	218	303
Other expenses	1,687	1,266	1,587
Total expenses	14,335	13,163	16,430
Income before income tax benefit and equity in undistributed income of subsidiaries	147,440	56,875	109,517
Income tax benefit	2,929	2,260	3,575
Income before equity in undistributed income of subsidiaries	150,369	59,135	113,092
Equity in undistributed income of subsidiaries	55,162	89,465	51,368
NET INCOME AVAILABLE TO COMMON STOCKHOLDERS	205,531	148,600	164,460
Net income	205,531	148,600	164,460
Other comprehensive income (loss)	(19,723)	46,962	49,296
Comprehensive income	$ 185,808	$ 195,562	$ 213,756