Accounts Receivable (Details) - Allowance for Doubtful Accounts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Allowance for doubtful accounts, beginning of year	$ 8,014	$ 7,674	$ 6,574
Charges to costs and expenses	807	1,723	1,571
Write-offs of uncollectible accounts, net of recoveries	(1,568)	(961)	(505)
Currency translation adjustments	(400)	(422)	34
Allowance for doubtful accounts, end of year	$ 6,853	$ 8,014	$ 7,674