Parent Company Financial Information (Condensed Statements Of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Net income	$ 33,526	$ 31,931	$ 28,337
Depreciation and amortization	6,177	5,958	5,429
Share-based compensation	1,174	845	674
(Increase) decrease in other assets	(24,505)	2,027	(545)
Decrease in other liabilities	4,016	257	376
Net cash provided by operating activities	46,279	46,694	43,089
Purchases of premises and equipment	(7,740)	(7,619)	(7,493)
Net cash paid for acquisition	676	868
Net cash used in investing activities	(372,614)	(326,677)	(305,874)
Issuance of long-term debt, net of issuance costs			40,000
Proceeds from stock options exercised	413	964	359
Net cash provided by financing activities	354,253	291,139	264,755
Net increase in cash and cash equivalents	27,918	11,156	1,970
Cash and cash equivalents, beginning of period	71,277	60,121	58,151
Cash and cash equivalents, end of period	99,195	71,277	60,121
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net income	33,526	31,931	28,337
Equity in undistributed earnings of subsidiary	(23,946)	(19,418)	(14,008)
Depreciation and amortization	149	148	97
Share-based compensation	1,174	845	674
(Increase) decrease in other assets	(1,673)	1,772	(1,069)
Decrease in other liabilities	(1,211)	(389)	(258)
Net cash provided by operating activities	8,019	14,889	13,773
Capital investment in Five Star Bank	(38,405)		(34,000)
Purchases of premises and equipment	(44)	(1,290)
Net cash paid for acquisition		(918)
Net cash used in investing activities	(38,449)	(2,208)	(34,000)
Issuance of long-term debt, net of issuance costs			38,940
Proceeds from issuance of common shares	38,303
Purchase of preferred and common shares	(157)		(202)
Proceeds from stock options exercised	413	964	359
Dividends paid	(13,958)	(12,946)	(12,721)
Other		30	79
Net cash provided by financing activities	24,601	(11,952)	26,455
Net increase in cash and cash equivalents	(5,829)	729	6,228
Cash and cash equivalents, beginning of period	16,516	15,787	9,559
Cash and cash equivalents, end of period	$ 10,687	$ 16,516	$ 15,787