Stock Based Awards and Other Equity Instruments (Tables)

9 Months Ended

Sep. 30, 2013

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Status and Activity for Stock Option Awards Relating to Common Stock

A summary of the status and activity for stock option awards relating to our common stock for the nine months ended September 30, 2013, is presented below:

	Options Outstanding		Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Life		Aggregate Intrinsic Value
	(In thousands)				(In years)		(In thousands)
Options outstanding at January 1, 2013		8,654	$	31.41
Granted		2,776		57.66
Exercised (1)		1,273		23.53			$	45,300
Cancelled		481		37.34
Options outstanding at September 30, 2013		9,676	$	39.69		6.1	$	349,716
Exercisable as of September 30, 2013		3,499	$	29.83		3.2	$	160,963
Vested and expected to vest after September 30, 2013		8,813	$	39.46		5.9	$	320,645

(1) Inclusive of 168,795 options which were not converted into shares due to net share settlement in order to cover the aggregate exercise price and the minimum amount of required employee withholding taxes. Potential shares which had been convertible under stock options that were withheld under net share settlement remain in the authorized but unissued pool under the 2011 Incentive Plan and can be reissued by the Company. We began net-share settling the majority of our stock option exercises during the third quarter of 2013. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the consolidated statements of cash flows.

Weighted-Average Assumptions of Estimated Fair Value of Stock Option Grants

The fair value of stock option grants under the 2011 Incentive Plan has been estimated at the date of grant using the Black–Scholes model with the following weighted average assumptions for the periods presented below:

	Three months ended September 30,						Nine months ended September 30,
	2013			2012			2013			2012
Risk free interest rate		1.83	%		0.90	%		1.40	%		1.03	%
Expected term (in years)		5.80			6.25			6.05			6.22
Expected volatility		49.62	%		54.78	%		50.81	%		53.54	%
Expected dividend yield		0	%		0	%		0	%		0	%

Summary of RSU Activity on Common Stock

The following table presents a summary of RSU activity on our common stock:

	RSUs Outstanding		Weighted Average Grant- Date Fair Value Per Share		Aggregate Intrinsic Value
	(In thousands)				(In thousands)
Unvested RSUs outstanding as of January 1, 2013		446	$	26.11
Granted		1,083		48.84
Vested and released (1)		333		22.51
Cancelled		76		44.81
Unvested RSUs outstanding as of September 30, 2013		1,120	$	47.27	$	84,989

(1) Inclusive of 127,199 RSUs withheld to satisfy employee minimum tax withholding requirements due to net share settlement. Potential shares which had been convertible under RSUs that were withheld under net share settlement remain in the authorized but unissued pool under the 2011 Incentive Plan and can be reissued by the Company. Total payments for the employees’ tax obligations to the taxing authorities due to net share settlements are reflected as a financing activity within the consolidated statements of cash flows.

Summary of Unrecognized Compensation Expense, Net of Estimated Forfeitures and Weighted Average Period Remaining

A summary of the unrecognized compensation expense, net of estimated forfeitures, and the weighted average period remaining at September 30, 2013 related to our non-vested stock options and RSU awards is presented below (in thousands, except year information):

	Stock Options		RSUs
Unrecognized compensation expense (net of forfeitures)	$	100,509	$	32,061
Weighted average period remaining (in years)		3.46		3.29