Valuation and Qualifying Accounts (Details) - 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]
Allowance for doubtful accounts receivable, period start	$ 24,287	$ 20,958	$ 18,369
Additions-charged to expense	10,095	8,653	6,631
Amounts written off	(6,179)	(4,079)	(5,944)
Other (primarily changes in foreign currency exchange rates)	(265)	(1,245)	1,902
Allowance for doubtful accounts receivable, period end	$ 27,938	$ 24,287	$ 20,958