Restructuring (Narrative) (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) Employee	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 6	$ 7
Restructuring Reserve	3		$ 4
Workforce Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 4
Restructuring and Related Cost, Expected Number of Positions Eliminated | Employee	47
Restructuring and Related Cost, Number of Positions Eliminated | Employee	43
Restructuring and Related Cost, Expected Cost	$ 15
Payments for Restructuring	$ 3
T17 Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Number of Positions Eliminated | Employee	673
Payments for Restructuring	$ 2
2018 Truck Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	1
Restructuring and Related Cost, Expected Cost	2
Payments for Restructuring	1
International [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	3		$ 3
International [Member] | Workforce Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	3
Payments for Restructuring	2
International [Member] | T17 Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Payments for Restructuring	1
International [Member] | 2018 Truck Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	0
Payments for Restructuring	$ 0