Employee Bargaining Agreements and Benefit Plans - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) Employees Pension_Plan	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Number of temporary employees | Employees	300
Expenses for defined contribution plan	$ 13	$ 14	$ 13
Number of benefit plans, description	The company sponsors two defined benefit plans in the UK which are frozen.
Defined benefit plan, concentration risk, description	the Company’s management believes that there are no significant concentrations of risk associated with plan assets.
UK [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plan | Pension_Plan	2
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of employees | Employees	4,500
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of employees collective bargaining agreement	1.00%
Net periodic benefit cost	$ 1	$ 1	$ 1
Defined benefit plan, expected future benefit payments in next twelve months	1
Defined benefit plan, expected future benefit payments in year two	1
Defined benefit plan, expected future benefit payments in year three	1
Defined benefit plan, expected future benefit payments in year four	1
Defined benefit plan, expected future benefit payments in year five	1
Defined benefit plan, expected future benefit payments in year five and thereafter	$ 3