Property and Equipment, Net (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Summary of Property and equipment
Cost	$ 947	$ 889
Accumulated depreciation	(531)	(458)
Net	416	431
Capitalized software [Member]
Summary of Property and equipment
Cost	629	600
Accumulated depreciation	(386)	(314)
Net	243	286
Furniture, fixtures and equipment [Member]
Summary of Property and equipment
Cost	274	240
Accumulated depreciation	(138)	(137)
Net	136	103
Building and leasehold improvements [Member]
Summary of Property and equipment
Cost	12	11
Accumulated depreciation	(7)	(7)
Net	5	4
Construction in progress [Member]
Summary of Property and equipment
Cost	32	38
Net	$ 32	$ 38

The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.

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Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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- Definition

Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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