Consolidated Balance Sheets Balance Sheet Parenthetical $ in Thousands	Mar. 31, 2016 USD ($) shares	Mar. 31, 2016 € / shares	Dec. 31, 2015 USD ($) shares	Dec. 31, 2015 € / shares
Allowance for Doubtful Accounts Receivable, Current | $	$ 3,240		$ 4,136
Common Stock, Par or Stated Value Per Share | € / shares		€ 0.02		€ 0.02
Common Stock, Shares Authorized	200,000,000		200,000,000
Common Stock, Shares, Issued	44,350,002		44,350,002
Common Stock, Shares, Outstanding	42,391,696		42,375,905
Treasury Stock, Shares	1,958,306		1,974,097
Preferred Stock, Par or Stated Value Per Share | € / shares		€ 0.02		€ 0.02
Preferred Stock, Shares Authorized	6,000,000		6,000,000
Preferred Stock, Shares Issued	0		0
Preferred Stock, Shares Outstanding	0		0