Employee Savings and Stock Ownership Plans (Detail 2) (USD $) In Millions, except Share data	12 Months Ended
Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Employee Savings and Stock Ownership Plans
Dividends on shares held by the ESOP		$ 31	$ 33
Company contributions to the ESOP		16	14
Interest incurred on ESOP notes		1	3
Amounts reported as employee benefit expense - expenses related to debt service		10	9
Amounts reported as employee benefit expense - expenses related to treasury shares		25	3
Amounts reported as employee benefit expense - expenses for Company contributions made in cash	$ 97	$ 6
ESOP Debt Shares
Allocated (in shares)		14,473,474	14,240,026
Committed to be released (in shares)			27,201
Unreleased (in shares)			1,333,692

The portion of plan compensation cost recognized during the period for expenses related to the Company's contributions to the ESOP made in cash.

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- Definition

The portion of plan compensation cost recognized during the period for expenses related to ESOP debt service.

+ Details

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- Definition

The portion of plan compensation cost recognized during the period for expenses related to treasury shares.

+ Details

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- Definition

An entity often discloses the amount of cash contributions paid to the ESOP.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 93-6
-Paragraph 53
-Subparagraph a

+ 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.

+ Details

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- Definition

Dividends paid on stock held by an employee stock option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 93-6
-Paragraph 53
-Subparagraph a

+ Details

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- Definition

An entity often discloses the amount of interest paid by the ESOP to a lender.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 93-6
-Paragraph 53

+ Details

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- Definition

The shares in an ESOP trust that have been assigned to individual participant accounts based on a known formula. IRS rules require allocations to be nondiscriminatory generally based on compensation, length of service, or a combination of both. For any particular participant such shares may be vested, unvested, or partially vested.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 93-6
-Paragraph 53
-Subparagraph d

+ Details

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- Definition

The shares that, although not legally released, will be released by a future scheduled and committed debt service payment and will be allocated to employees for service rendered in the current accounting period. The ESOP documents typically define the period of service to which the shares relate. ESOP shares are released to compensate employees directly, to settle employer liabilities for other employee benefits, and to replace dividends on allocated shares that are used for debt service.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 93-6
-Paragraph 53
-Subparagraph d

+ Details

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- Definition

Shares contributed to the ESOP that have not yet been released, committed to be released, or allocated to participant accounts. Suspense shares generally collateralize ESOP debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 93-6
-Paragraph 53
-Subparagraph d

+ Details

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