Intangible Assets - Schedule of Intangible Assets by Major Class (Detail) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Gross Book Value	$ 12,462	$ 12,465
Accumulated Amortization	3,851	3,738
Net Book Value	8,611	8,727
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Gross Book Value	4,772	4,768
Accumulated Amortization	1,302	1,243
Net Book Value	3,470	3,525
Technology/Technical Know-How
Finite Lived Intangible Assets [Line Items]
Gross Book Value	3,463	3,494
Accumulated Amortization	1,275	1,246
Net Book Value	2,188	2,248
Tradenames
Finite Lived Intangible Assets [Line Items]
Gross Book Value	2,799	2,799
Accumulated Amortization	653	628
Net Book Value	2,146	2,171
Other
Finite Lived Intangible Assets [Line Items]
Gross Book Value	1,428	1,404
Accumulated Amortization	621	621
Net Book Value	$ 807	$ 783