Valuation And Qualifying Accounts (Detail) - Allowance for doubtful accounts receivable - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of period		$ 5,095	$ 5,339	$ 4,073
Charged to costs and expenses		1,609	1,103	1,216
Charged to other accounts		0	0	0
Other	[1]	(1,163)	(1,139)	(520)
Balance at end of period		5,485	5,095	5,339
Foreign Currency Translation [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Cumulative translation adjustment		$ (56)	$ (208)	$ 570

[1] Uncollectible accounts written off, net of recoveries.