Stock-based compensation

6 Months Ended

Jun. 30, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Incentive Award Plan and Employee Stock Purchase Plan

10. Stock-based compensation

On March 31, 2015, the Company issued 125,101 shares of common stock under the On Assignment 2010 Employee Stock Purchase Plan (the "ESPP"). 

Compensation expense related to stock-based compensation, including the ESPP, was $5.2 million and $4.1 million for the three months endedJune 30, 2015 and 2014, respectively, of which $5.2 million was included in SG&A expense for 2015; and $3.9 million was included in SG&A expense and $0.2 million was included in income from discontinued operations for 2014 in the accompanying condensed consolidated statements of operations and comprehensive income. 

Compensation expense related to stock-based compensation, including the ESPP, was $9.2 million and $7.3 million for the six months endedJune 30, 2015 and 2014, respectively of which $9.2 million was included in SG&A expense for 2015; and $7.0 million was included in SG&A expense and $0.3 million was included in income from discontinued operations for 2014 in the accompanying condensed consolidated statements of operations and comprehensive income.