Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Employee waiting period after hire to participate in the defined contribution plans	90 days
Employee maximum contribution towards defined contribution plans as percentage of annual compensation	50.00%
Employee maximum contribution towards defined contribution plans as percentage of annual incentive plan bonus	80.00%
Percentage of contribution upon eligibility for non union employees hired after threshold period	3.00%
Employer's match in cash of non-union employee contributions on first specified percentage of eligible compensation	100.00%
First percentage of eligible compensation on which specified percentage of non-union employee contribution is matched by the employer in cash	3.00%
Employer's match in cash of non-union employee contributions on next specified percentage of eligible compensation	50.00%
Next percentage of eligible compensation on which specified percentage of non-union employee contribution is matched by the employer in cash	3.00%
Employer maximum match of non-union employee contribution on eligible compensation	4.50%
Defined contribution plans expense	$ 88	$ 80	$ 70
Accrued benefit liabilities	19	21
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Combined accumulated benefit obligation of pension plans	141	120
Plan assets of pension plans	136	117
Unfunded benefit obligation	5	3
Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Unfunded benefit obligation	$ 14	$ 18

Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level.

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Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

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Employee maximum contribution towards defined contribution plans as percentage of annual incentive plan

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