Long-Term Employee Benefit Liabilities - Summary of Weighted Average Significant Actuarial Assumptions Adopted in Measuring Company's Obligations and Cost (Detail) - Pension Plan, Defined Benefit [Member]	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.10%	2.50%
Rate of compensation increase	2.40%	2.60%
Net periodic benefit cost Discount rate	2.80%	3.20%
Rate of compensation increase	2.40%	2.60%
Expected return on plan assets	4.60%	4.90%

Long-Term Employee Benefit Liabilities - Summary of Weighted Average Significant Actuarial Assumptions Adopted in Measuring Company's Obligations and Cost (Detail) - Pension Plan, Defined Benefit [Member]

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Defined Benefit Plan Disclosure [Line Items]

Discount rate

2.10%

2.50%

Rate of compensation increase

2.40%

2.60%

Net periodic benefit cost Discount rate

2.80%

3.20%

Rate of compensation increase

2.40%

2.60%

Expected return on plan assets

4.60%

4.90%