Employee Benefits - Pension Plans Narrative (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Percentage of the Company's projected benefit obligation	93.00%
U.S. Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plans with PBO in excess of the fair value of plan assets, PBO	$ 3,300,000,000	$ 2,700,000,000
Plans with ABO in excess of the fair value of plan assets, ABO	3,300,000,000	2,700,000,000
Plans with ABO in excess of the fair value of plan assets, fair value of plan assets	2,000,000,000	1,900,000,000
Future amortization of loss	(56,000,000)
U.K. [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plans with PBO in excess of the fair value of plan assets, PBO	1,300,000,000	1,200,000,000
Plans with ABO in excess of the fair value of plan assets, ABO	1,300,000,000	1,200,000,000
Plans with ABO in excess of the fair value of plan assets, fair value of plan assets	1,100,000,000	1,000,000,000
Plans with PBO in excess of the fair value of plan assets	1,100,000,000	1,000,000,000
Future amortization of loss	(54,000,000)
Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plans with PBO in excess of the fair value of plan assets, PBO	1,400,000,000	1,200,000,000
Plans with ABO in excess of the fair value of plan assets, ABO	1,300,000,000	400,000,000
Plans with ABO in excess of the fair value of plan assets, fair value of plan assets	1,200,000,000	300,000,000
Plans with PBO in excess of the fair value of plan assets	$ 1,200,000,000	$ 1,000,000,000

Represents the percentage of the company's total pension obligations represented within the tables provided.

No definition available.

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- Definition

Amount included in accumulated other comprehensive income (AOCI) related to gain (loss) expected to be recognized as components of net periodic benefit cost for the fiscal year that follows the most recent annual statement of financial position.

+ References

No definition available.

+ Details

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- Definition

If aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 55

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=32704760&loc=d3e4179-114921

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e2417-114920

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- Definition

If aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

+ Details

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- Definition

If aggregate disclosures are presented, the aggregate benefit obligation for plans with benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e2417-114920

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- Definition

If aggregate disclosures are presented, the aggregate fair value of plan assets for plans with benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References

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