Assets Acquired In FDIC-Assisted Acquisitions - Changes in FDIC Shared Loss Receivable (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Beginning balance	$ 242,394	$ 177,187
Indemnification asset recorded in acquisitions	52,654	94,973
Payments received from FDIC	(128,730)	(36,813)
Effect of change in expected cash flows on covered assets	(6,594)	7,047
Balance, end of year	$ 159,724	$ 242,394

The amount of indemnification assets (amounts to be reimbursed if and when certain assumed liabilities are paid) recognized at the acquisition date of a business combination.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant