Consolidated Balance Sheets Balance Sheet Parenthetical In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014 USD ($)	Jun. 30, 2014 EUR (€)	Dec. 31, 2013 USD ($)	Dec. 31, 2013 EUR (€)
Allowance for Doubtful Accounts Receivable, Current	$ 3,371		$ 2,872
Common Stock, Par or Stated Value Per Share		€ 0.02		€ 0.02
Common Stock, Shares Authorized	200,000,000	200,000,000	200,000,000	200,000,000
Common Stock, Shares, Issued	46,750,002	46,750,002	46,750,002	46,750,002
Common Stock, Shares, Outstanding	44,480,019	44,480,019	45,101,389	45,101,389
Treasury Stock, Shares	2,269,983	2,269,983	1,648,613	1,648,613
Preferred Stock, Par or Stated Value Per Share		€ 0.02		€ 0.02
Preferred Stock, Shares Authorized	6,000,000	6,000,000	6,000,000	6,000,000
Preferred Stock, Shares Issued	0	0	0	0
Preferred Stock, Shares Outstanding	0	0	0	0