Intangible Assets and Goodwill (Intangible Assets and Goodwill) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 379	$ 379
Accumulated Amortization	235	198
Net Carrying Value	144	181
Client relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	274	274
Accumulated Amortization	169	144
Net Carrying Value	105	130
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	89	89
Accumulated Amortization	56	47
Net Carrying Value	33	42
Trade name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	16	16
Accumulated Amortization	10	7
Net Carrying Value	$ 6	$ 9