Parent Company Financial Statements (Condensed Statements of Income and Comprehensive Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
EXPENSES
Salaries and Employee Benefits	$ 68,570	$ 68,112	$ 63,885
Professional Fees	5,009	3,998	4,674
Interest Expense	9,549	19,126	31,249
INCOME BEFORE INCOME TAXES AND EQUITY IN UNDISTRIBUTED INCOME OF SUBSIDIARIES	102,785	75,044	71,239
Income Tax Benefit	(18,648)	(12,834)	(12,017)
NET INCOME	84,137	62,210	59,222
Other Comprehensive Income:
Changes in Unrecognized Loss in Postretirement Benefit Obligation, Net	0	0	(229)
Parent Company
INCOME
Interest Income	109	118	102
Other Income (Loss)	11	25	(2)
Total Income	66,590	41,723	46,500
EXPENSES
Salaries and Employee Benefits	537	498	530
Professional Fees	1,256	564	1,685
Occupancy and Equipment Expense	10	7	7
Interest Expense	2,763	2,907	2,781
Other Expenses	1,200	1,286	975
Total Expenses	5,766	5,262	5,978
INCOME BEFORE INCOME TAXES AND EQUITY IN UNDISTRIBUTED INCOME OF SUBSIDIARIES	60,824	36,461	40,522
Income Tax Benefit	1,607	1,922	1,712
INCOME BEFORE EQUITY IN UNDISTRIBUTED INCOME OF SUBSIDIARIES	62,431	38,383	42,234
Equity in Undistributed Income of Subsidiaries	21,706	23,827	16,988
NET INCOME	84,137	62,210	59,222
Other Comprehensive Income:
Changes in Unrealized Gain (Loss) on Securities, Available-for-Sale	(19,891)	20,270	22,432
Changes in Unrecognized Loss in Postretirement Benefit Obligation, Net	0	0	(229)
COMPREHENSIVE INCOME	64,246	82,480	81,425
Parent Company | Bank
INCOME
Dividends from Subsidiaries	65,000	40,000	45,000
Parent Company | Non-bank
INCOME
Dividends from Subsidiaries	$ 1,470	$ 1,580	$ 1,400