Pension and Other Post Retirement Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Insurance policy value	$ 2,966,000	$ 2,592,000
401(k) Plan
Defined Benefit Plan Disclosure [Line Items]
Cost recognized for contributions to defined contribution plan	1,275,000	$ 1,384,000	$ 1,471,000
United States
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected employer contribution in next fiscal year	0
German Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected employer contribution in next fiscal year	$ 0