Schedule of Plan Assets Category (Detail)	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Asset Allocation	100.00%	100.00%
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Asset Allocation	15.00%	24.00%
Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Asset Allocation	84.00%	73.00%
Other
Defined Benefit Plan Disclosure [Line Items]
Asset Allocation	1.00%	3.00%