Postretirement Benefit Plans - Defined Benefit Pension Plans - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2022 USD ($)
Defined Contribution Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Balance of trust assets	$ 2,114,000
United States [Member] | Unfunded Plan [Member] | Non-qualified Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contributions or payments to defined benefit plans	276,000
Employer contributions or payments	171,000
U.K Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contributions or payments to defined benefit plans	505,000
Employer contributions or payments	$ 253,000