Retirement Plans and Other Post-Retirement Benefits - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Employer contribution of employee’s eligible earnings, percentage			10.00%
Pension settlement charge, net of post settlement adjustments	$ 389		$ 6,792
Payment to third party related to qualified pension liabilities	$ 400
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension settlement charge, net of post settlement adjustments		$ 6,300
Reversion of excess pension plan assets		55,500
Amount transferred to suspense account to fund future 401(k) contributions		14,100
Accruing of excise taxes		8,200
Available for general corporate purposes		$ 33,100