Goodwill and Other Intangible Assets (Other Intangible Assets Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired during the year	$ 1,000,000
Finite-Lived Intangible Assets, Gross	82,000,000	$ 76,000,000
Finite-Lived Intangible Assets, Net	31,000,000	39,000,000
Indefinite-Lived Intangible Assets (Excluding Goodwill)	121,000,000	131,000,000
Capitalized Computer Software, Gross	1,500,000,000	1,500,000,000
Capitalized Computer Software, Net	771,000,000	790,000,000
Capitalized Computer Software, Development Stage Costs	39,000,000
Impairment of long-lived assets	$ 68,000,000	17,000,000	$ 12,000,000
Amortization of software to be abandoned		75,000,000
Finite-Lived Intangible Assets, Except Capitalized Internal-Use Software [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Weighted-Average Useful Life	4 years
Acquired Finite-lived Intangible Asset, Residual Value	$ 0
Amortization expense	15,000,000	13,000,000	6,000,000
Amortization expense for 2016	15,000,000
Amortization expense for 2017	5,000,000
Amortization expense for 2018	4,000,000
Amortization expense for 2019	2,000,000
Amortization expense for 2020	2,000,000
Amortization expense thereafter	3,000,000
Capitalized Internal Use Software [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Residual Value	0
Amortization expense	212,000,000	260,000,000	$ 139,000,000
Amortization expense for 2016	219,000,000
Amortization expense for 2017	179,000,000
Amortization expense for 2018	111,000,000
Amortization expense for 2019	65,000,000
Amortization expense for 2020	62,000,000
Amortization expense thereafter	$ 135,000,000
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
Software In-Process [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment of long-lived assets		$ 24,000,000
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