Goodwill and Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Amortizable intangible assets:
Customer lists	$ 678	$ 678	$ 678
Customer Lists Accumulated Amortization	428	417	372
Core deposit premiums	8,560	7,974	7,867
Core Deposit premiums accumulated amortization	5,316	5,128	4,499
[FiniteLivedIntangibleAssetsGross]	9,238	8,652	8,545
FiniteLivedIntangibleAssetsAccumulatedAmortization	5,744	5,545	4,871
Unamortizable intangible assets:
Goodwill	$ 65,835	$ 65,835	$ 65,835