Average Investment Term, Alternative Investments

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Number of days notice required to redeem an investment.

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Maximum percentage of funds permitted to be invested.

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- Definition

Number of Real Estate and Private Equity Partnerships

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- Definition

For defined benefit pension plans, the actuarial present value of benefits (whether vested or nonvested) attributed by the pension benefit formula to employee service rendered before a specified date and based on employee service and compensation (if applicable) before that date. The accumulated benefit obligation differs from the projected benefit obligation in that it includes no assumption about future compensation levels. For plans with flat-benefit or nonpay-related pension benefit formulas, the accumulated benefit obligation and the projected benefit obligation are the same.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Accumulated Benefit Obligation

-URI http://asc.fasb.org/extlink&oid=6503844

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

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- Definition

Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

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- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

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- Definition

States the frequency (for example, annually, semi-annually, quarterly) with which the entity can redeem its investment, or portion thereof, for each of those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments), by major category.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 6A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=SL6742756-110258

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- Definition

The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 6A

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=SL6742756-110258

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Retirement Benefits (Details 12) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 partnership	Dec. 31, 2013	Dec. 31, 2012
Defined Contribution Plans Disclosure (Amounts in paragraphs)
Maximum percentage of employee compensation eligible for cash matching of employee contributions	4.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 282	$ 285	$ 293
Pension and post-retirement benefits disclosures (Amounts in paragraphs)
Accumulated benefit obligation for all defined benefit pension plans	30,300	25,700
Information About Plan Assets (Amounts in paragraphs) [Abstract]
Maximum percentage of funds permitted to be invested in trust accounts	5.00%
Number of real estate and private equity partnerships	164
Entities that calculate net asset value per share, unfunded commitments	833	899
Average investment term, alternative investments	10 years
Entities that calculate net asset value per share, investment redemption frequency	quarterly
Notice period for alternative investments redemptions, days	90 days
OPEB contributions
Defined Contribution Plans Disclosure (Amounts in paragraphs)
Expected 2015 employer contributions	68
Pension employer required minimum contributions
Defined Contribution Plans Disclosure (Amounts in paragraphs)
Expected 2015 employer contributions	77
Voluntary Contributions
Defined Contribution Plans Disclosure (Amounts in paragraphs)
Expected 2015 employer contributions	$ 500