Benefit Plans - Weighted-Average Asset Allocation of Pension Plan Assets (Detail) - Pension	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation percentage	100.00%	100.00%
Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation percentage	39.00%	39.00%
Foreign equities
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation percentage	11.00%	12.00%
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation percentage	48.00%	47.00%
Real estate
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation percentage	2.00%	2.00%
Cash
Defined Benefit Plan Disclosure [Line Items]
Weighted-average asset allocation percentage	0.00%	0.00%