Allowance For Doubtful Accounts - Rollforward (Details) (Allowance for Doubtful Accounts [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 7,133	$ 6,399	$ 4,569
Charged to Costs and Expenses	(264)	1,136	2,072
Write-Offs Charged to Allowance	(296)	(407)	(737)
Effect of Exchange Rate Changes	(75)	5	495
Ending Balance	$ 6,498	$ 7,133	$ 6,399