Treasury Stock	12 Months Ended
Dec. 31, 2016
Treasruy Stock [Abstract]
Treasury Stock [Text Block]	Treasury Stock In July 2010, our Board of Directors approved a common stock purchase plan to purchase up to $40.0 million of our common stock. This plan has no expiration date and we have $7.2 million remaining on this purchase plan. During 2016 and 2014, we purchased $15.4 million and $5.6 million, respectively of our common stock. We did not purchase any of our common stock under our purchase plan in 2015. We used the treasury stock to issue shares for stock option exercises, restricted stock grants and employee stock purchase plan stock purchases. In 2016, we withheld 20,261 shares of our common stock from employee vested restricted stock units in consideration for $1.9 million in payments for the employee's share award income tax withholding obligations. We have 93 shares remaining in treasury at December 31, 2016. In 2015, we withheld 17,299 shares of our common stock from employee vested restricted stock units in consideration for $1.5 million in payments for the employee's share award income tax withholding obligations. We also withheld 823 shares of our common stock from option exercises with shares remitted back to us in lieu of $0.1 million in cash payments for the option exercises.

Treasury Stock

In July 2010, our Board of Directors approved a common stock purchase plan to purchase up to $40.0 million of our common stock. This plan has no expiration date and we have $7.2 million remaining on this purchase plan. During 2016 and 2014, we purchased $15.4 million and $5.6 million, respectively of our common stock. We did not purchase any of our common stock under our purchase plan in 2015. We used the treasury stock to issue shares for stock option exercises, restricted stock grants and employee stock purchase plan stock purchases.

In 2016, we withheld 20,261 shares of our common stock from employee vested restricted stock units in consideration for $1.9 million in payments for the employee's share award income tax withholding obligations. We have 93 shares remaining in treasury at December 31, 2016.

In 2015, we withheld 17,299 shares of our common stock from employee vested restricted stock units in consideration for $1.5 million in payments for the employee's share award income tax withholding obligations. We also withheld 823 shares of our common stock from option exercises with shares remitted back to us in lieu of $0.1 million in cash payments for the option exercises.