Subsequent Event - Additional Information (Detail) - Subsequent Event [Member] - Bank of Commerce $ in Millions	Jul. 14, 2015 USD ($)
Subsequent Event [Line Items]
Assets and liabilities purchased	$ 202
Loans	139
Deposits	180
Equity capital	$ 21

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration