Other Assets (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended
	Jul. 31, 2010	Mar. 31, 2014
Variable Interest Entity [Line Items]
Unconsolidated Partnership, assets		$ 400
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Company limited partner holding interest, percentage	99.90%
Unamortized investment balance classified as Other Assets		361
Remaining commitments classified as Other Liabilities		18
Maximum exposure to loss		361
Remaining commitments expected to be paid in 2014		$ 18
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
General partner holding interest, percentage	0.10%