Investment Securities (Detail) $ in Billions	Mar. 31, 2016 USD ($) Security	Dec. 31, 2015 USD ($) Security
Net Investment Income
Carrying value of pledged securities \| $	$ 1.4	$ 1.4
Number of debt securities held	85	252
Unrealized losses on debt securities (percent of amortized cost)	0.87%	1.10%
Obligations of States and Political Subdivisions
Net Investment Income
Number of securities in a continuous loss position for over twelve months	1

Number of available for sale securities continuous unrealized loss position twelve months or longer.

No definition available.

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- Definition

The number of securities held in the investment portfolio with unrealized losses at the end of the current period.

+ References

No definition available.

+ Details

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- Definition

Unrealized losses on total debt securities, gross, as a percentage of the unamortized cost basis of the securities.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

The carrying amount (fair value) as of the balance sheet date of securities held that had been pledged by counterparties under financing and lending arrangements, pursuant to which the entity has the right by agreement or custom to sell or re-pledge such securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5086-111524

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