Stockholders' Equity and Equity Compensation Plans (Tables)

9 Months Ended

Sep. 30, 2016

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 third quarter and nine months ended is as follows (shares in thousands):

	Quarter Ended					Nine Months Ended
	September 30, 2016					September 30, 2016
	Shares			Weighted- Average Grant Date Fair Value		Shares			Weighted- Average Grant Date Fair Value
Unvested awards, beginning		1,744		$	30.51		2,124		$	26.03
Awards granted		39			42.47		523			39.06
Awards forfeited/cancelled		(116	)		31.04		(278	)		29.63
Awards vested		(230	)		27.09		(932	)		24.08
Unvested awards, ending		1,437		$	31.34		1,437		$	31.34