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Basis of Presentation - Recent Aquisitions (Details) - USD ($) shares in Millions, $ in Millions	Mar. 11, 2019	Jan. 07, 2019	Mar. 28, 2018	Mar. 07, 2018
Avetc
Business Acquisition [Line Items]
Consideration transferred	$ 136
VaaS
Business Acquisition [Line Items]
Consideration transferred		$ 445
Acquired debt		38
Cash payments		$ 231
Shares issued (in shares)		1.4
Share value		$ 160
Total consideration		391
Cash paid for acquisition		$ 231
Avigilon
Business Acquisition [Line Items]
Consideration transferred			$ 974
Acquired debt			75
Cash payments			980
Total consideration			$ 974
Plant Holdings, Inc.
Business Acquisition [Line Items]
Cash paid for acquisition				$ 237