Consolidated Balance Sheets Balance Sheet Parenthetical $ in Thousands	Mar. 31, 2017 USD ($) shares	Mar. 31, 2017 € / shares	Dec. 31, 2016 USD ($) shares	Dec. 31, 2016 € / shares
Allowance for Doubtful Accounts Receivable, Current | $	$ 3,133		$ 3,139
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	44,796,252		44,796,252
Common Stock, Shares, Outstanding	44,175,731		44,151,261
Treasury Stock, Shares	620,521		644,991
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