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Postretirement Benefit Plans - Defined Benefit Plans - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Feb. 17, 2022
Feb. 24, 2021
Feb. 24, 2020
Defined Benefit Plan Disclosure [Line Items]            
Assets gains or losses added for prior year 80.00%          
Assets gains or losses added for second preceding year 60.00%          
Assets gains or losses added for third preceding year 40.00%          
Assets gains or losses added for fourth preceding year 20.00%          
United States [Member]            
Defined Benefit Plan Disclosure [Line Items]            
Common shares sold to the Company's ESOP trust       33,983 31,362 32,706
Expected long-term rate of return on assets 5.50% 6.75% 6.75%      
Expected payment related to qualified plan $ 0          
Expected payment related to non-qualified plan $ 278,000          
U.K Plans [Member]            
Defined Benefit Plan Disclosure [Line Items]            
Expected long-term rate of return on assets 1.61% 1.13% 2.30%      
Percentage of premium estimated return for equities and properties to risk free rate 3.00%          
Percentage of long term return in cash 3.50%          
Expected payment related to qualified plan $ 451,000          
Equities [Member]            
Defined Benefit Plan Disclosure [Line Items]            
Percentage of target allocation for investment category 25.00%          
Percentage of target allocation for investment including stock category 35.00%          
Expected long-term rate of return on assets 7.98%          
Equities [Member] | U.K Plans [Member]            
Defined Benefit Plan Disclosure [Line Items]            
Percentage of target allocation for investment category 11.00%          
Debt Securities [Member] | United States [Member]            
Defined Benefit Plan Disclosure [Line Items]            
Percentage of target allocation for investment category 63.00%          
Debt Securities [Member] | U.K Plans [Member]            
Defined Benefit Plan Disclosure [Line Items]            
Percentage of target allocation for investment category 75.00%          
Cash [Member] | United States [Member]            
Defined Benefit Plan Disclosure [Line Items]            
Percentage of target allocation for investment category 2.00%          
Cash [Member] | U.K Plans [Member]            
Defined Benefit Plan Disclosure [Line Items]            
Percentage of target allocation for investment category 10.00%          
Insurance Contracts [Member] | U.K Plans [Member]            
Defined Benefit Plan Disclosure [Line Items]            
Percentage of target allocation for investment category 4.00%          
U.S. and international equities [Member]            
Defined Benefit Plan Disclosure [Line Items]            
Expected long-term rate of return on assets 4.05%