Fair Value Measurements Other Segments Fair Value (Details) - Other Segments and Holding Company [Member] - Fair Value, Measurement Frequency [Domain] - USD ($) $ in Millions		Jun. 30, 2015	Dec. 31, 2014
Assets [Abstract]
Derivative contracts, at fair value (asset)	[1]	$ 23	$ 47
Assets, Fair Value Disclosure		231	288
Liabilities [Abstract]
Other Liabilities, Fair Value Disclosure		14	50
Derivative contracts at fair value (liability)	[2]	8	2
Available-for-sale Securities		208	186
Trading Securities		0	55
Financial and Nonfinancial Liabilities, Fair Value Disclosure		22	52
Fair Value, Inputs, Level 1 [Member]
Assets [Abstract]
Derivative contracts, at fair value (asset)	[1]	0	0
Assets, Fair Value Disclosure		10	75
Liabilities [Abstract]
Other Liabilities, Fair Value Disclosure		0	0
Derivative contracts at fair value (liability)	[2]	0	0
Available-for-sale Securities		10	75
Trading Securities		0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure		0	0
Fair Value, Inputs, Level 2 [Member]
Assets [Abstract]
Derivative contracts, at fair value (asset)	[1]	23	47
Assets, Fair Value Disclosure		23	50
Liabilities [Abstract]
Other Liabilities, Fair Value Disclosure		14	50
Derivative contracts at fair value (liability)	[2]	8	2
Available-for-sale Securities		0	3
Trading Securities		0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure		22	52
Fair Value, Inputs, Level 3 [Member]
Assets [Abstract]
Derivative contracts, at fair value (asset)	[1]	0	0
Assets, Fair Value Disclosure		198	163
Liabilities [Abstract]
Other Liabilities, Fair Value Disclosure		0	0
Derivative contracts at fair value (liability)	[2]	0	0
Available-for-sale Securities		198	108
Trading Securities		0	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.