Securities - Amortized Cost and Fair Value of Asset Backed Securities (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Available-for-sale securities: Fair Value	$ 4,227	$ 4,742
Held-to-maturity Securities, Amortized Cost	1,462	1,620
Held-to-maturity Securities: Fair Value	3	9
Asset backed securities [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Available-for-sale securities, Amortized Cost	273	424
Available-for-sale securities: Unrealized Losses for More Than 12 Months	(36)	(70)
Available-for-sale securities: Fair Value	237	354
Total Amortized Cost Basis		431
Total Unrealized Losses for More Than 12 Months		(70)
Total Fair Value		361
Asset backed securities [Member] \| Residential mortgages [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost		7
Held-to-maturity Securities, Unrealized Losses for More Than 12 Months		0
Held-to-maturity Securities: Fair Value		7
Asset backed securities [Member] \| Commercial mortgages [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Available-for-sale securities, Amortized Cost	10	11
Available-for-sale securities: Unrealized Losses for More Than 12 Months	0	0
Available-for-sale securities: Fair Value	10	11
Asset backed securities [Member] \| Home equity [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Available-for-sale securities, Amortized Cost	263	311
Available-for-sale securities: Unrealized Losses for More Than 12 Months	(36)	(52)
Available-for-sale securities: Fair Value	227	259
Asset backed securities [Member] \| Other [Member]
Schedule of Available-for-sale and Held-to-maturity Securities [Line Items]
Available-for-sale securities, Amortized Cost		102
Available-for-sale securities: Unrealized Losses for More Than 12 Months		(18)
Available-for-sale securities: Fair Value		$ 84

Available-for-sale Debt Securities and Held-to-maturity Debt Securities, Amortized Cost Basis

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- Definition

Available-for-sale Debt Securities and Held-to-maturity Debt Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses

+ References

No definition available.

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Available-for-sale Debt Securities and Held-to-maturity Debt Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value

+ References

No definition available.

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- Definition

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

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- Definition

Amount of unrealized loss on securities classified as available-for-sale that have been in a loss position for twelve months or longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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- Definition

This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for twelve months or longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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- Definition

Amount before other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

+ References

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- Definition

Amount of unrealized loss on investments in held-to-maturity securities that have been in a loss position for twelve months or longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 7

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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This item represents the fair value of securities categorized as held-to-maturity securities that have been in a continuous unrealized loss position for twelve months or longer.

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