Quarterly Results of Operations - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effect Of Fourth Quarter Events [Line Items]
Income (loss), net of income taxes	$ 4,300	$ 3,900	$ 4,600	$ 1,900	$ 6,300	$ (1,600)	$ 5,900	$ 15,200	$ 14,680	$ 25,844	$ (41,017)
Litigation Settlement Expense
Effect Of Fourth Quarter Events [Line Items]
Income (loss), net of income taxes							(15,200)
Gain From a Sale of Excess Property
Effect Of Fourth Quarter Events [Line Items]
Income (loss), net of income taxes						3,500
Gain From the Sale of Insurance And Risk Management
Effect Of Fourth Quarter Events [Line Items]
Income (loss), net of income taxes					2,400
Insurance Recoveries
Effect Of Fourth Quarter Events [Line Items]
Income (loss), net of income taxes			$ 100	$ 300		$ 200	$ 3,700	$ 200		$ 4,100
Decrease In German Trade Tax Rate \| Kronos
Effect Of Fourth Quarter Events [Line Items]
Income (loss), net of income taxes					(1,300)
Favorable Settlement Of Prior Year Tax Matter \| Kronos
Effect Of Fourth Quarter Events [Line Items]
Income (loss), net of income taxes					700
Insurance Settlement Gains \| Kronos
Effect Of Fourth Quarter Events [Line Items]
Income (loss), net of income taxes					$ 500