Consolidated Balance Sheets Balance Sheet Parenthetical $ in Thousands	Dec. 31, 2015 USD ($) shares	Dec. 31, 2015 € / shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2014 € / shares
Allowance for Doubtful Accounts Receivable, Current | $	$ 4,136		$ 3,397
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		45,600,002
Common Stock, Shares, Outstanding	42,375,905		43,636,984
Treasury Stock, Shares	1,974,097		1,963,018
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