Pension Plan and Life Insurance Contract - Assumptions to Determine Company's Benefit Obligation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Amounts in Accumulated Other Comprehensive Income Not Yet Recognized In Net Periodic Benefit Cost	$ 4,000	$ 2,600
Defined Benefit Plan, Plan Assets, Amount	$ 15,296	$ 16,384
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	1.71%	1.64%	1.49%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	1.03%	1.71%	1.64%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase	0.00%	0.00%	0.00%
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Measurement Date	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	0.00%	0.00%	0.00%