Goodwill and Other Intangible Assets (Other Intangible Assets Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 18,000,000		$ 41,000,000
Finite-Lived Intangible Assets, Net	13,000,000		14,000,000
Indefinite-Lived Intangible Assets (Excluding Goodwill)	79,000,000		86,000,000
Capitalized Computer Software, Gross	1,400,000,000		1,300,000,000
Capitalized Computer Software, Net	585,000,000		$ 574,000,000
Capitalized Computer Software, Development Stage Costs	49,000,000
Impairment of Long-Lived Assets Held-for-use	$ 250,000,000	$ 17,000,000
Finite-Lived Intangible Assets, Except Capitalized Internal-Use Software [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Weighted-Average Useful Life	6 years
Acquired Finite-lived Intangible Asset, Residual Value	$ 0
Amortization expense	2,000,000	4,000,000
Amortization expense for remainder 2017	3,000,000
Amortization expense for 2018	3,000,000
Amortization expense for 2019	2,000,000
Amortization expense for 2020	1,000,000
Amortization expense for 2021	1,000,000
Amortization expense for 2022	1,000,000
Amortization expense thereafter	2,000,000
Capitalized Internal Use Software [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Residual Value	0
Amortization expense	49,000,000	$ 55,000,000
Amortization expense for remainder 2017	152,000,000
Amortization expense for 2018	140,000,000
Amortization expense for 2019	92,000,000
Amortization expense for 2020	58,000,000
Amortization expense for 2021	52,000,000
Amortization expense for 2022	38,000,000
Amortization expense thereafter	$ 53,000,000
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