Fair Value Measurements - Transfers Between Levels & Contingent Consideration (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
	Jul. 29, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Level 2 to Level 1 Transfers			$ 0		$ 0
Contingent Consideration Commission payable		$ 32		$ 32
Contingent Consideration basis		4
Lattice
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent Consideration	$ 0
Contingent Consideration Payment Period	4 years
Lattice | Contingent Obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount Rate				16.70%
US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Level 1 to Level 2 Transfers		$ 379	$ 300	$ 1,300	$ 1,100