Stockholders' Deficit (Tables)

12 Months Ended

Dec. 31, 2016

Stockholders' Equity Note [Abstract]

Schedule of change in the number of shares of Class A common stock

The following table sets forth the change in the number of shares of Class A common stock outstanding during the fiscal years ended December 31, 2016 and 2015:

	December 31,
	2016	2015
Shares outstanding as of beginning of period	86.5	85.1
Shares issued as part of equity-based compensation plans and the ESPP, net of shares surrendered	1.5	1.4
Shares outstanding as of end of period	88.0	86.5

RSUs outstanding under equity-based compensation plans

A summary of the changes in RSUs outstanding under our equity-based compensation plans during 2016 is presented below:

	Number of Restricted Stock Units		Weighted Average Grant Date Fair Value
Unvested RSUs as of December 31, 2015	5.6		$	13.05
Granted	2.1		$	9.35
Vested	(1.9	)	$	12.73
Cancelled	(0.9	)	$	12.63
Unvested RSUs as of December 31, 2016	4.9		$	11.68