Parent Company Financial Statements (Statements of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 76,870	$ 69,829	$ 69,118
Adjustments to reconcile net income to net cash provided by operating activities:
Tax (expense) benefit from stock option exercises and other equity awards	182	(103)	248
Deferred income tax expense (benefit)	2,155	(3,130)	(1,491)
(Increase) decrease in other assets	38,935	(57,730)	(27,961)
Net cash provided by (used in) operating activities	100,812	36,478	73,435
Cash flows from investing activities:
Purchases of other equity investments, net	(650)	0	0
Net cash provided by (used in) investing activities	(240,899)	(264,240)	(160,115)
Cash flows from financing activities:
Treasury stock purchased	0	(4,322)	0
Net proceeds from stock option exercises and issuance of other equity awards, net of awards surrendered	(177)	(470)	273
Cash dividends paid	(36,349)	(35,499)	(34,189)
Net cash provided by (used in) financing activities	116,312	291,575	131,660
Cash and cash equivalents at beginning of year	202,268	138,455	93,475
Cash and cash equivalents at end of year	178,493	202,268	138,455
Parent Company [Member]
Cash flows from operating activities:
Net income	76,870	69,829	69,118
Adjustments to reconcile net income to net cash provided by operating activities:
Tax (expense) benefit from stock option exercises and other equity awards	182	(103)	248
Deferred income tax expense (benefit)	(24)	0	0
(Increase) decrease in dividend receivable	(1,128)	(2,261)	(1,813)
(Increase) decrease in other assets	50	109	(43)
Increase (decrease) in accrued expenses and other liabilities	31	(31)	(15)
Other, net	(182)	193	(195)
Net cash provided by (used in) operating activities	43,808	40,111	33,842
Cash flows from investing activities:
Purchases of other equity investments, net	(650)	0	0
Net cash provided by (used in) investing activities	(650)	0	0
Cash flows from financing activities:
Treasury stock purchased	0	(4,322)	0
Net proceeds from stock option exercises and issuance of other equity awards, net of awards surrendered	(177)	(470)	273
Cash dividends paid	(36,349)	(35,499)	(34,189)
Net cash provided by (used in) financing activities	(36,526)	(40,291)	(33,916)
Net increase (decrease) in cash and cash equivalents	6,632	(180)	(74)
Cash and cash equivalents at beginning of year	1,658	1,838	1,912
Cash and cash equivalents at end of year	8,290	1,658	1,838
Bank [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed earnings (losses) of subsidiaries	(32,045)	(27,603)	(33,445)
Non-bank [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed earnings (losses) of subsidiaries	$ 54	$ (22)	$ (13)