Goodwill and Other Intangible Assets - Components of Intangible Assets (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Amortized intangible assets
Gross Carrying Amount	$ 16,931	$ 16,516
Accumulated Amortization and Fair Value Adjustments	10,475	11,646
Net Carrying Amount	6,456	4,870
Covenants not to compete [Member]
Amortized intangible assets
Gross Carrying Amount		320
Accumulated Amortization and Fair Value Adjustments		320
Branch acquisitions [Member]
Amortized intangible assets
Gross Carrying Amount		2,951
Accumulated Amortization and Fair Value Adjustments		2,951
Core deposit intangibles [Member]
Amortized intangible assets
Gross Carrying Amount	2,201	2,201
Accumulated Amortization and Fair Value Adjustments	2,201	2,148
Net Carrying Amount		53
Customer related intangibles [Member]
Amortized intangible assets
Gross Carrying Amount	6,250	5,291
Accumulated Amortization and Fair Value Adjustments	3,946	3,213
Net Carrying Amount	2,304	2,078
Mortgage servicing rights [Member]
Amortized intangible assets
Gross Carrying Amount	8,480	5,753
Accumulated Amortization and Fair Value Adjustments	4,328	3,014
Net Carrying Amount	$ 4,152	$ 2,739