Long-Term Commitments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commitments and Contingencies Disclosure [Abstract]
Net rental costs	$ 403	$ 416	$ 430
Rentals from subleases	$ 13	$ 10	$ 9
Office Building [Member] \| Lease Concentration Risk [Member] \| Lease Obligations [Member]
Concentration Risk [Line Items]
Lease obligations for office space	98.00%

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

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- Definition

Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income.

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-Name Accounting Standards Codification

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- Definition

The total amount of sublease rental income recognized during the period that reduces the entity's rent expense incurred under operating leases.

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