Parent Company Financial Information (Condensed Statements Of Cash Flows) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Flows From Operating Activities:
Net income		$ 46,932	$ 43,089	$ 41,203
Adjustments to reconcile net income to net cash provided by operating activities:
Deferred income tax provision		670	(56)	(1,331)
Stock-based compensation expense		2,466	1,635	1,788
Other increases		(2,501)	3,093	(531)
Net cash provided by operating activities		51,424	50,781	46,035
Cash Flows From Financing Activities:
Repurchase of common stock		(17,889)	(14,501)	(7,935)
Proceeds from exercise of stock options		133	526
Proceeds from issuance of common stock, net of shares withheld		263	607	(188)
Cash dividends paid		(18,591)	(18,261)	(17,421)
Net cash provided by (used in) financing activities		212,850	(34,294)	(72,616)
Net increase (decrease) in cash and cash equivalents		30,503	(167,507)	172,214
Cash and cash equivalents, beginning of year		43,675	211,182	38,968
Cash and cash equivalents, end of period		74,178	43,675	211,182
Supplemental Schedule of Noncash Financing Activities:
Cash dividends payable		4,713	4,648	4,519
Parent Company [Member]
Cash Flows From Operating Activities:
Net income		46,932	43,089	41,203
Adjustments to reconcile net income to net cash provided by operating activities:
Undistributed earnings of subsidiary bank		(12,546)	(12,001)	(17,722)
Deferred income tax provision		(199)	533	495
Stock-based compensation expense		2,466	1,635	1,788
Decrease (increase) in other assets		(1)
Increase (decrease) in other liabilities		5	1	(1)
Other increases		(530)	(1,112)	(941)
Net cash provided by operating activities		36,127	32,145	24,822
Cash Flows From Investing Activities:
Capital contributions to Bank subsidiary
Cash Flows From Financing Activities:
Repurchase of common stock		(17,889)	(14,501)	(7,935)
Proceeds from issuance of common stock, net of shares withheld		263	607	(188)
Cash dividends paid		(18,591)	(18,261)	(17,421)
Net cash provided by (used in) financing activities		(36,217)	(32,155)	(25,544)
Net increase (decrease) in cash and cash equivalents	[1]	(90)	(10)	(722)
Cash and cash equivalents, beginning of year		987	997	1,719
Cash and cash equivalents, end of period		897	987	997
Supplemental Schedule of Noncash Financing Activities:
Cash dividends payable		$ 4,713	$ 4,648	$ 4,519

[1] Cash and cash equivalents is defined as cash and due from banks and includes the checking and money market accounts with the Corporation’s wholly-owned bank subsidiary.