Goodwill and Intangibles (Details) (USD $)	3 Months Ended
	Mar. 31, 2013 Bonds		Mar. 31, 2013 Core Deposit Intangible Assets [Member]	Dec. 31, 2012 Core Deposit Intangible Assets [Member]
Changes to carrying amount of goodwill [Roll Forward]
Goodwill, beginning of period	$ 42,781,000	[1]
Adjustment to goodwill	(105,000)
Goodwill, end of period	42,676,000
Goodwill acquired during the year	415,000
Goodwill market value adjustment	254,000
Number of bonds held in investment portfolio at acquisition	2
Net of deferred taxes adjustment resulted in reduction to goodwill	105,000
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount			9,047,000	11,674,000
Less accumulated amortization			(276,000)	(2,627,000)
Net carrying amount			$ 8,771,000	$ 9,047,000

[1] Derived from audited financial statements