Description of Business and Basis of Presentation (Narrative) (Details) - USD ($) $ in Billions		6 Months Ended
	Jun. 20, 2018	Dec. 31, 2018
Disclosure Basis Of Presentation Details [Line Items]
Period over which the tax basis is expected to result in additional annual tax deductions		15 years
Tax Cuts and Jobs Act, maximum measurement period to finalize recording of related tax impacts from enactment date		1 year
Fiscal 2019
Disclosure Basis Of Presentation Details [Line Items]
U.S. statutory federal rate		21.00%
Separation And Distribution Agreement | Pending Distribution Not Yet Completed
Disclosure Basis Of Presentation Details [Line Items]
Dividend to be paid immediately prior to the Distribution	$ 8.5
Separation And Distribution Agreement | Pending Distribution Not Yet Completed | Maximum
Disclosure Basis Of Presentation Details [Line Items]
Amount of taxes in respect of the Separation and Distribution and divestitures (collectively, the Transaction Tax).	8.5
Amount of cash payment calculated by subtracting the final estimate of the Transaction Tax and $8.5 billion	$ 2.0