Goodwill and Other Intangibles - Other Intangible Assets and Related Accumulated Amortization (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Schedule Of Indefinite And Finite Lived Intangible Assets [Line Items]
Other intangible assets subject to amortization, Gross	$ 2,129	$ 2,162
Other intangible assets subject to amortization, Accumulated Amortization	1,640	1,643
Other intangible assets subject to amortization, Net	489	519
Total other intangible assets, Gross	2,402	2,435
Total other intangible assets, Net	$ 762	792	[1]
Minimum [Member]
Schedule Of Indefinite And Finite Lived Intangible Assets [Line Items]
Other intangible assets subject to amortization, Weighted Average Life	5 years
Maximum [Member]
Schedule Of Indefinite And Finite Lived Intangible Assets [Line Items]
Other intangible assets subject to amortization, Weighted Average Life	25 years
Trademarks [Member]
Schedule Of Indefinite And Finite Lived Intangible Assets [Line Items]
Other intangible assets not subject to amortization	$ 273	273
Dealer networks [Member]
Schedule Of Indefinite And Finite Lived Intangible Assets [Line Items]
Other intangible assets subject to amortization, Gross	321	328
Other intangible assets subject to amortization, Accumulated Amortization	200	199
Other intangible assets subject to amortization, Net	$ 121	129
Other intangible assets subject to amortization, Weighted Average Life	15 years
Patents, concessions and licenses and other [Member]
Schedule Of Indefinite And Finite Lived Intangible Assets [Line Items]
Other intangible assets subject to amortization, Gross	$ 1,808	1,834
Other intangible assets subject to amortization, Accumulated Amortization	1,440	1,444
Other intangible assets subject to amortization, Net	$ 368	$ 390
Patents, concessions and licenses and other [Member] | Minimum [Member]
Schedule Of Indefinite And Finite Lived Intangible Assets [Line Items]
Other intangible assets subject to amortization, Weighted Average Life	5 years
Patents, concessions and licenses and other [Member] | Maximum [Member]
Schedule Of Indefinite And Finite Lived Intangible Assets [Line Items]
Other intangible assets subject to amortization, Weighted Average Life	25 years

[1] 2017 figures have been recast following the retrospective adoption on January 1, 2018, of the updated accounting standard for revenue recognition (ASC 606).