Available-for-sale Securities Fair Value and Gross Realized Gains (Losses) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
Jun. 30, 2013
Investments, Debt and Equity Securities [Abstract]
Available-for-sale securities, gross realized gains	$ 1.2
Available-for-sale securities, gross realized losses	0
Fair value of sold available-for-sale securities	44.2
Other-than-temporary impairments	$ 0
Bank of America common stock owned	1,800,000

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

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The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period.

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This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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Balance held at close of period in number of shares.

+ References

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

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-Name Accounting Standards Codification

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-SubTopic 320

-Section S99

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- Definition

Amount before tax of other than temporary impairment (OTTI) on investment in available-for-sale debt security, recognized in other comprehensive loss.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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