Goodwill and Intangible Assets - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2012	Dec. 31, 2011
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 21,582	$ 21,582
Goodwill impairment charge	$ 0
Cash flow period	5 years
Capitalization rate	10.00%
Discount rate	13.00%
Core Deposits [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated useful life	10 years

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