Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended		3 Months Ended
Dec. 31, 2012	Mar. 31, 2013	Mar. 31, 2013 Core Deposit Intangibles	Dec. 31, 2012 Core Deposit Intangibles
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 21,582	$ 21,582
Goodwill impairment charge	0
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life			10 years
Core deposit intangibles			1,367	1,367
Less: accumulated amortization			806	773
Carrying value of core deposit intangibles	$ 594	$ 561	$ 561	$ 594

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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+ Details

- Definition

Loss recognized during the period that results from the write-down of goodwill after comparing the implied fair value of reporting unit goodwill with the carrying amount of that goodwill. Goodwill is assessed at least annually for impairment.

+ References

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+ Details