Fair Value Measurements Other Segments Fair Value (Details) (Other Segments and Holding Company [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Assets [Abstract]
Derivative contracts, at fair value (asset)	$ 22	[1]	$ 47	[1]
Assets, Fair Value Disclosure	211		288
Liabilities [Abstract]
Other Liabilities, Fair Value Disclosure	42		50
Derivative contracts at fair value (liability)	21	[2]	2	[2]
Available-for-sale Securities	111		186
Trading Securities	78		55
Financial and Nonfinancial Liabilities, Fair Value Disclosure	63		52
Fair Value, Inputs, Level 1 [Member]
Assets [Abstract]
Derivative contracts, at fair value (asset)	0	[1]	0	[1]
Assets, Fair Value Disclosure	39		75
Liabilities [Abstract]
Other Liabilities, Fair Value Disclosure	0		0
Derivative contracts at fair value (liability)	0	[2]	0	[2]
Available-for-sale Securities	1		75
Trading Securities	38		0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0		0
Fair Value, Inputs, Level 2 [Member]
Assets [Abstract]
Derivative contracts, at fair value (asset)	22	[1]	47	[1]
Assets, Fair Value Disclosure	22		50
Liabilities [Abstract]
Other Liabilities, Fair Value Disclosure	42		50
Derivative contracts at fair value (liability)	21	[2]	2	[2]
Available-for-sale Securities	0		3
Trading Securities	0		0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	63		52
Fair Value, Inputs, Level 3 [Member]
Assets [Abstract]
Derivative contracts, at fair value (asset)	0	[1]	0	[1]
Assets, Fair Value Disclosure	150		163
Liabilities [Abstract]
Other Liabilities, Fair Value Disclosure	0		0
Derivative contracts at fair value (liability)	0	[2]	0	[2]
Available-for-sale Securities	110		108
Trading Securities	40		55
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 0		$ 0

[1] Amounts are classified within other assets in our condensed consolidated balance sheets.

[2] Amounts are classified within accrued expenses and other liabilities in our condensed consolidated balance sheets.