Valuation and Qualifying Accounts (Schedule of Valuation and Qualifying Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reserve for sales discounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	$ 13,488	$ 15,094	$ 15,999
Net Charged to Costs and Expenses	82,724	77,126	78,304
Translations, Reclassifications and Acquisitions	166	(109)	(145)
Net Write-Offs or Discounts Taken	(80,726)	(78,623)	(79,064)
Balance End of Year	15,652	13,488	15,094
Reserve for inventory obsolescence
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	7,262	9,675	7,601
Net Charged to Costs and Expenses	3,007	2,041	5,209
Translations, Reclassifications and Acquisitions	886	295	(454)
Net Write-Offs or Discounts Taken	(4,223)	(4,749)	(2,681)
Balance End of Year	6,932	7,262	9,675
Reserve for warranty
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	5,262	5,566	5,913
Net Charged to Costs and Expenses	7,224	7,867	7,732
Translations, Reclassifications and Acquisitions	567	(49)	(325)
Net Write-Offs or Discounts Taken	(7,718)	(8,122)	(7,754)
Balance End of Year	$ 5,335	$ 5,262	$ 5,566