Assets Acquired In FDIC-Assisted Acquisitions (Changes In FDIC Shared Loss Receivable) (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Balance	$ 242,394	$ 177,187	$ 177,187
Indemnification asset recorded in acquisitions	52,654	94,973	94,973
Payments received from FDIC	(97,399)	(22,107)	(36,813)
Effect of change in expected cash flows on covered assets	791	(10,334)	7,047
Ending balance	$ 198,440	$ 239,719	$ 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