Employee Benefit Plan

12 Months Ended

Dec. 31, 2012

Compensation and Retirement Disclosure [Abstract]

Compensation and Employee Benefit Plans [Text Block]

(8) Employee Benefit Plan

We offer the GP Retirement Savings Plan (the “Plan”) to our employees. Eligible employees are automatically enrolled unless they elect to not participate in the Plan, and contributions begin as soon as administratively feasible after enrollment. The Plan permits pre-tax contributions to the Plan by participants pursuant to Section 401(k) of the Internal Revenue Code (IRC). We make matching contributions at our discretion. In 2012, 2011 and 2010, we contributed 107,728, 93,472, and 48,440 shares, respectively, of our common stock directly to the Plan with a value of approximately $1,835,000, $1,108,000 and $440,000, respectively. In addition, we contributed cash, net of forfeitures, of $150,000, $334,000 and $160,000 to the Plan for matching contributions for the years ended December 31, 2012, 2011 and 2010, respectively. For the years ended December 31, 2012, 2011 and 2010, we recognized total compensation expense of $2,086,000, $1,520,000 and $601,000, respectively, in the consolidated statements of operations for matching contributions to the Plan.