Summary of Significant Accounting Policies - Property Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 641	$ 598
Less accumulated depreciation	(377)	(306)
Property, plant and equipment, net	264	292
Depreciation	$ 79	75	$ 69
Buildings
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful lives	30 years
Property, plant and equipment, gross	$ 54	51
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8	10
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	233	226
Furniture and office equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	19	15
Software and computer equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	235	197
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	69	64
Projects in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 23	$ 35
Minimum | Property, plant and equipment, other
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful lives	3 years
Maximum | Property, plant and equipment, other
Property, Plant and Equipment [Line Items]
Property plant and equipment, estimated useful lives	10 years