Goodwill and Other Intangible Assets (Other Intangible Assets Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired during the year			$ 0
Finite-Lived Intangible Assets, Gross	$ 36,000,000		36,000,000		$ 82,000,000
Finite-Lived Intangible Assets, Net	11,000,000		11,000,000		31,000,000
Indefinite-Lived Intangible Assets (Excluding Goodwill)	106,000,000		106,000,000		121,000,000
Capitalized Computer Software, Gross	1,400,000,000		1,400,000,000		1,500,000,000
Capitalized Computer Software, Net	643,000,000		643,000,000		$ 771,000,000
Capitalized Computer Software, Development Stage Costs	44,000,000		$ 44,000,000
Finite-Lived Intangible Assets, Except Capitalized Internal-Use Software [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Weighted-Average Useful Life			1 year
Acquired Finite-lived Intangible Asset, Residual Value	0		$ 0
Amortization expense	3,000,000	$ 4,000,000	7,000,000	$ 7,000,000
Amortization expense for remainder 2016	6,000,000		6,000,000
Amortization expense for 2017	3,000,000		3,000,000
Amortization expense for 2018	2,000,000		2,000,000
Capitalized Internal Use Software [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Residual Value	0		0
Amortization expense	50,000,000	$ 53,000,000	105,000,000	$ 106,000,000
Amortization expense for remainder 2016	91,000,000		91,000,000
Amortization expense for 2017	176,000,000		176,000,000
Amortization expense for 2018	113,000,000		113,000,000
Amortization expense for 2019	73,000,000		73,000,000
Amortization expense for 2020	60,000,000		60,000,000
Amortization expense for 2021	50,000,000		50,000,000
Amortization expense thereafter	$ 80,000,000		$ 80,000,000
Capitalized Internal Use Software, Except Significant System Conversions [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Weighted-Average Useful Life			3 years
Minimum [Member] | Capitalized Internal Use Software, Significant System Conversions [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Weighted-Average Useful Life			8 years
Maximum [Member] | Capitalized Internal Use Software, Significant System Conversions [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Weighted-Average Useful Life			10 years