Parent Company Financial Statements (Statements of Income) (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]                      
Interest on borrowings                 $ 3,329 $ 3,137 $ 5,363
Salaries and employee benefits                 32,669 32,609 29,689
Furniture, equipment and data processing                 7,316 7,051 5,079
Net occupancy                 5,055 5,449 4,365
Income before income tax 8,611 9,605 9,317 8,477 7,984 9,318 9,283 8,330 36,010 34,915 34,310
Income tax benefit (2,523) (3,154) (3,001) (2,762) (3,560) (2,952) (2,952) (2,668) (11,440) (12,132) (10,882)
Net income 6,088 6,451 6,316 5,715 4,424 6,366 6,331 5,662 24,570 22,783 23,428
Parent Company [Member]                      
Condensed Financial Statements, Captions [Line Items]                      
Dividend income from subsidiaries                 12,800 13,500 13,400
Fees from subsidiaries                 0 20,930 20,070
Other income                 104 270 170
Total operating income                 12,904 34,700 33,640
Interest on borrowings                 2,532 2,532 2,546
Fees to Bank                 160 0 0
Salaries and employee benefits                 0 13,354 13,007
Furniture, equipment and data processing                 0 4,570 3,971
Depreciation and amortization                 0 1,197 1,196
Compensation expense                 0 596 538
Net occupancy                 0 523 492
Other operating expenses                 453 1,454 1,056
Total operating expenses                 3,145 24,226 22,806
Income before equity in undistributed earnings of subsidiaries and income taxes                 9,759 10,474 10,834
Equity in undistributed earnings of subsidiaries                 13,799 11,233 11,647
Income before income tax                 23,558 21,707 22,481
Income tax benefit                 1,012 1,076 947
Net income                 $ 24,570 $ 22,783 $ 23,428