Treasury Stock	6 Months Ended
Jun. 30, 2016
Treasury 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. For the six months ended June 30, 2016 we purchased 174,885 shares of our common stock for $15.4 million, including commissions. As of June 30, 2016, we had $7.2 million remaining on this purchase plan. We expect to use the treasury stock to issue shares for stock option exercises, restricted stock grants and employee stock purchase plan stock purchases. Additionally, for the six months ended June 30, 2016, we withheld 17,661 shares of our common stock from employee vested restricted stock units in consideration for $1.6 million in payments made on the employee's behalf for their minimum statutory income tax withholding obligations.

Treasury Stock

6 Months Ended

Jun. 30, 2016

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. For the six months ended June 30, 2016 we purchased 174,885 shares of our common stock for $15.4 million, including commissions. As of June 30, 2016, we had $7.2 million remaining on this purchase plan. We expect to use the treasury stock to issue shares for stock option exercises, restricted stock grants and employee stock purchase plan stock purchases.

Additionally, for the six months ended June 30, 2016, we withheld 17,661 shares of our common stock from employee vested restricted stock units in consideration for $1.6 million in payments made on the employee's behalf for their minimum statutory income tax withholding obligations.