Fair Value Measurements Changes in Fair Value Level 3 (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Holding Company [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, [Roll Forward]
Balance at January 1	$ 116	$ 81
Purchases	0	67
Distribution-in-kind	110	0
Gross realized and unrealized (losses) gains	(96)	(32)
Balance at December 31	130	116
Investment Segment [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, [Roll Forward]
Balance at January 1	287	288
Distribution-in-kind	(110)	0
Gross realized and unrealized (losses) gains	(100)	4
Gross proceeds	(2)	(5)
Balance at December 31	75	287
Level 3 [Member] \| Recurring measurement [Member] \| Railcar and Food Packaging [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, [Roll Forward]
Balance at January 1	21	30
Realized/unrealized gains (losses), net	1	3
Purchases and settlements, net	(1)	(12)
Balance at December 31	21	21
Level 3 [Member] \| United States Plans \| Recurring measurement [Member] \| Automotive Segment [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, [Roll Forward]
Balance at January 1	85	14
Realized/unrealized gains (losses), net	6	11
Purchases and settlements, net	47	83
Gross proceeds	(47)	(23)
Balance at December 31	91	85
Level 3 [Member] \| Non-U.S. Plans \| Recurring measurement [Member] \| Automotive Segment [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, [Roll Forward]
Balance at January 1	44	42
Realized/unrealized gains (losses), net	2	1
Purchases and settlements, net	6	6
Gross proceeds	(5)	(6)
Foreign currency exchange rate movements	(6)	1
Balance at December 31	$ 41	$ 44

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, distribution in kind

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- Definition

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Foreign Exchange Movements

+ References

No definition available.

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- Definition

Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Net Realized And Unrealized Gains Losses

+ References

No definition available.

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- Definition

Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Amount of purchases, (sales), issuances and (settlements) of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph c

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- Definition

Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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