Summary of Changes to Restructuring-Related Liabilities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Balance, beginning	$ 4	$ 6	$ 11
Restructuring expense	(22)	(63)	(29)
Balance, ending	2	4	6
Americas
Restructuring Cost and Reserve [Line Items]
Balance, beginning	1	1	1
Balance, ending	0	1	1
International
Restructuring Cost and Reserve [Line Items]
Balance, beginning	3	5	10
Balance, ending	2	3	5
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning	4	5	10
Balance, ending	1	4	5
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning	0	1	1
Balance, ending	0	0	1
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Balance, beginning	0	0	0
Balance, ending	1	0	0
2011 Avis Europe Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense			1
Cash payment/utilization			(1)
2011 Avis Europe Restructuring [Member] | Americas
Restructuring Cost and Reserve [Line Items]
Restructuring expense			0
Cash payment/utilization			0
2011 Avis Europe Restructuring [Member] | International
Restructuring Cost and Reserve [Line Items]
Restructuring expense			1
Cash payment/utilization			(1)
2011 Avis Europe Restructuring [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense			1
Cash payment/utilization			(1)
2011 Avis Europe Restructuring [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense			0
Cash payment/utilization			0
2011 Avis Europe Restructuring [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense			0
Cash payment/utilization			0
2018 Truck Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(5)	(5)
Cash payment/utilization	(5)	(5)
2018 Truck Restructuring [Member] | Americas
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(5)	(5)
Cash payment/utilization	(5)	(5)
2018 Truck Restructuring [Member] | International
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	0
Cash payment/utilization	0	0
2018 Truck Restructuring [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(1)	(1)
Cash payment/utilization	(1)	(1)
2018 Truck Restructuring [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	0
Cash payment/utilization	0	0
2018 Truck Restructuring [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(4)	(4)
Cash payment/utilization	(4)	(4)
Workforce Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(13)
Cash payment/utilization	(12)
Workforce Restructuring [Member] | Americas
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(4)
Cash payment/utilization	(4)
Workforce Restructuring [Member] | International
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(9)
Cash payment/utilization	(8)
Workforce Restructuring [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(11)
Cash payment/utilization	(11)
Workforce Restructuring [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0
Cash payment/utilization	0
Workforce Restructuring [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(2)
Cash payment/utilization	(1)
T17 Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(2)	(35)
Cash payment/utilization	(5)	(33)
T17 Restructuring [Member] | Americas
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(2)	(25)
Cash payment/utilization	(3)	(24)
T17 Restructuring [Member] | International
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	(10)
Cash payment/utilization	(2)	(9)
T17 Restructuring [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	(20)
Cash payment/utilization	(3)	(17)
T17 Restructuring [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0	0
Cash payment/utilization	0	(1)
T17 Restructuring [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(2)	(15)
Cash payment/utilization	(2)	(15)
2014 T15 Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(1)		(21)
Cash payment/utilization	(1)	(3)	(18)
2014 T15 Restructuring [Member] | Americas
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0		(11)
Cash payment/utilization	0	(1)	(11)
2014 T15 Restructuring [Member] | International
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(1)		(10)
Cash payment/utilization	(1)	(2)	(7)
2014 T15 Restructuring [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	(1)		(15)
Cash payment/utilization		(3)	(12)
2014 T15 Restructuring [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0		(1)
Cash payment/utilization		0	(1)
2014 T15 Restructuring [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	0		(5)
Cash payment/utilization		0	(5)
2015 Acquisition Integration [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense			(9)
Cash payment/utilization	(1)	(1)	(15)
2015 Acquisition Integration [Member] | Americas
Restructuring Cost and Reserve [Line Items]
Restructuring expense			0
Cash payment/utilization		0	0
2015 Acquisition Integration [Member] | International
Restructuring Cost and Reserve [Line Items]
Restructuring expense			(9)
Cash payment/utilization		(1)	(15)
2015 Acquisition Integration [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense			(9)
Cash payment/utilization	(1)	(1)	(15)
2015 Acquisition Integration [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense			0
Cash payment/utilization	0	0	0
2015 Acquisition Integration [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense			0
Cash payment/utilization	$ 0	$ 0	$ 0