Quarterly Results of Operations (Unaudited) (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended	3 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Jun. 30, 2010 Bank and trust services	Jun. 30, 2010 Residential mortgage loan loss provision Bank and trust services
Error corrections
Increase (decrease) to net income resulting from correction of an error that is material to quarterly results of operations					$ (21.4)
Provision: Mortgage loan valuation allowance	$ 44.2	$ 152.9	$ 148.5	$ 41.9

Amount of the item included in the interim period that affected period-to-period comparability (excluding restatement adjustments).

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 28

-Paragraph 31

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 270

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6952194&loc=d3e1570-108306

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