Stockholders' Equity and Equity Compensation Plans (Tables)

3 Months Ended

Mar. 31, 2015

Stockholders Equity Note [Abstract]

Summary of Unvested Restricted Common Stock Activity

Stock-Based Awards. A summary of our unvested restricted common stock activity during the first quarter of 2015 is as follows (shares in thousands):

	Quarter Ended March 31, 2015
	Shares			Weighted- Average  Grant Date  Fair Value
Unvested awards, beginning		2,311		$	22.81
Awards granted		588			29.64
Awards forfeited/cancelled		(17	)		21.46
Awards vested		(572	)		19.82
Unvested awards, ending		2,310		$	25.30