Goodwill and Other Intangible Assets (Other Intangible Assets Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired during the year			$ 10,000,000
Finite-Lived Intangible Assets, Gross	$ 34,000,000		34,000,000		$ 82,000,000
Finite-Lived Intangible Assets, Net	8,000,000		8,000,000		31,000,000
Indefinite-Lived Intangible Assets (Excluding Goodwill)	111,000,000		111,000,000		121,000,000
Capitalized Computer Software, Gross	1,400,000,000		1,400,000,000		1,500,000,000
Capitalized Computer Software, Net	629,000,000		629,000,000		$ 771,000,000
Capitalized Computer Software, Development Stage Costs	58,000,000		$ 58,000,000
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	10,000,000	$ 7,000,000
Amortization expense for remainder 2016	3,000,000		3,000,000
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	48,000,000	$ 49,000,000	153,000,000	$ 155,000,000
Amortization expense for remainder 2016	46,000,000		46,000,000
Amortization expense for 2017	186,000,000		186,000,000
Amortization expense for 2018	122,000,000		122,000,000
Amortization expense for 2019	80,000,000		80,000,000
Amortization expense for 2020	65,000,000		65,000,000
Amortization expense for 2021	52,000,000		52,000,000
Amortization expense thereafter	$ 78,000,000		$ 78,000,000
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