Business Combinations Acquired Non-impaired Loans Fair Value at Acquisition Date (Details) (Citizens Republic Bancorp, USD $) In Thousands, unless otherwise specified	0 Months Ended
Apr. 12, 2013
Nonimpaired Loans Fair Value at Acquisition Date [Line Items]
Business Combination, Acquired Receivables, Fair Value	$ 4,617,004
non-impaired
Nonimpaired Loans Fair Value at Acquisition Date [Line Items]
Receivables Carrying Value at Acquisition Date	4,017,304
Goodwill, Purchase Accounting Adjustments	220,015
Business Combination, Acquired Receivables, Fair Value	$ 3,797,289

Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 25

-Paragraph 16

-URI http://asc.fasb.org/extlink&oid=21917927&loc=d3e961-128460

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