Employee Benefits - Components of Net Periodic Pension Costs - Postretirement Benefits Other Than Pensions (Detail) - Post-Retirement Benefits Other Than Pensions - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 338	$ 291	$ 290
Interest cost	648	789	941
Amortization of prior service costs	(1,747)	(1,747)	(1,747)
Amortization of net actuarial loss	975	887	621
Net periodic pension costs	$ 214	$ 220	$ 105