Stockholders' Equity and Equity Compensation Plans (Tables)

3 Months Ended

Mar. 31, 2017

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 is as follows (shares in thousands):

	Quarter Ended March 31, 2017
	Shares			Weighted- Average Grant Date Fair Value
Unvested awards, beginning		1,394		$	31.26
Awards granted		473			39.48
Awards forfeited/cancelled		(9	)		31.49
Awards vested		(439	)		28.35
Unvested awards, ending		1,419		$	34.90