Goodwill and Other Intangible Assets (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Accumulated amortization of intangible assets
Gross Carrying Amount	$ 17,479	$ 17,479
Accumulated Amortization	(9,240)	(7,068)
Net Carrying Amount	8,239	10,411
Core deposit intangibles [Member]
Accumulated amortization of intangible assets
Gross Carrying Amount	16,759	16,760
Accumulated Amortization	(8,829)	(6,871)
Net Carrying Amount	7,930	9,889
Non-compete covenant [Member]
Accumulated amortization of intangible assets
Gross Carrying Amount	102	102
Accumulated Amortization	(51)	(25)
Net Carrying Amount	51	77
Lease intangible [Member]
Accumulated amortization of intangible assets
Gross Carrying Amount	618	617
Accumulated Amortization	(360)	(172)
Net Carrying Amount	$ 258	$ 445