Parent Company Financial Statements (Statements of Cash Flows) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Activities
Net Income	$ 24,570	$ 22,783	$ 23,428
Depreciation and amortization expense	3,051	3,004	2,500
Stock-based compensation expense	599	596	538
(Increase) decrease in other assets	(3,380)	193	1,556
Net cash provided by operating activities	29,886	29,732	42,329
Investing Activities
Purchase of premises and equipment	(1,316)	(1,490)	(3,403)
Net cash (used) provided by investing activities	(170,512)	(166,911)	32,138
Financing Activities
Exercise of stock options and issuance of restricted stock, net of repurchase for tax withholdings and tax benefit	(328)	(300)	212
Common stock repurchase	(7,475)	(2,460)	(2,097)
Cash dividends paid on common stock	(8,085)	(8,121)	(7,667)
Net cash provided (used) by financing activities	150,084	130,244	(55,502)
Net increase (decrease) in cash and cash equivalents	9,458	(6,935)	18,965
Cash and cash equivalents at beginning of year	51,355	58,290	39,325
Cash and cash equivalents at end of year	60,813	51,355	58,290
Common stock repurchased not yet settled	0	320	0
Parent Company [Member]
Operating Activities
Net Income	24,570	22,783	23,428
Equity in undistributed earnings of subsidiaries	(13,799)	(11,233)	(11,647)
Depreciation and amortization expense	0	1,197	1,196
Stock-based compensation expense	0	596	538
Decrease (increase) in amount receivable from subsidiaries	2,037	498	(983)
(Increase) decrease in other assets	165	(845)	(1,334)
(Decrease) increase in accrued expenses	(2,106)	459	636
Net cash provided by operating activities	10,867	13,455	11,834
Investing Activities
Proceeds from sale of assets	5,237	0	0
Purchase of premises and equipment	0	(896)	(1,009)
Net cash (used) provided by investing activities	5,237	(896)	(1,009)
Financing Activities
Exercise of stock options and issuance of restricted stock, net of repurchase for tax withholdings and tax benefit	(328)	(300)	212
Capital contribution from subsidiaries	599	0	0
Common stock repurchase	(7,475)	(2,460)	(2,097)
Cash dividends paid on common stock	(8,085)	(8,121)	(7,667)
Net cash provided (used) by financing activities	(14,633)	(10,281)	(9,976)
Net increase (decrease) in cash and cash equivalents	1,471	2,278	849
Cash and cash equivalents at beginning of year	21,788	19,510	18,661
Cash and cash equivalents at end of year	23,259	21,788	19,510
Common stock repurchased not yet settled	$ 0	$ 320	$ 0