Acquisitions (Pro Forma Financial Information) (Narrative) (Details) - IDT - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Jun. 29, 2018	Dec. 31, 2018
Fair value adjustment to inventory
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma earnings, adjustments	$ (1)
Acquisition-related transaction costs
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma earnings, adjustments		$ (15)

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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+ Details