Stock Option Plans (Tables)

12 Months Ended

Dec. 31, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

The following table summarizes the stock option activity which contain only service conditions, under the Company’s 1999, 2009 and 2010 Plans (in thousands, except per share and term information):



	Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding, December 31, 2012	6,610		$	12.49	8.2	$	112,899
Granted	2,394		43.32
Exercised	(1,566	)	8.58
Forfeited	(311	)	27.00
Outstanding, December 31, 2013	7,127		23.07		8.1	215,549
Exercisable at December 31, 2013	2,890		10.46		7.0	123,833
Vested and expected to vest at December 31, 2013	7,022		$	22.91	8.1	$	213,492

Schedule of stock options outstanding and exercisable by range of exercise prices

The following table summarizes information about stock options, which contain only service conditions, under the Company’s equity incentive plans at December 31, 2013 (in thousands except term information):



	Options Outstanding at December 31, 2013		Options Exercisable at December 31, 2013
	Number of Options	Weighted Average Remaining Contractual Term (in years)	Number of Options	Weighted Average Remaining Contractual Term (in years)
Range of Exercise Prices
$0.34 to $1.65	841	5.6	800	5.5
$5.93 to $8.88	1,219	6.9	866	6.9
$12.54 to $15.41	596	7.7	289	7.7
$16.24 to $18.82	732	8.0	458	8.0
$20.85 to $23.94	1,095	8.4	366	8.4
$27.75 to $31.44	394	8.9	104	8.8
$33.34 to $36.15	609	9.2	4	9.2
$40.03 to $45.76	895	9.5	2	9.8
$50.42 to $52.72	746	9.7	1	9.9
	7,127	8.1	2,890	7.0

Schedule of restricted stock unit activity

Restricted stock unit activity for the year ended December 31, 2013 under the Company’s equity incentive plans is summarized as follows (shares in thousands):



	Number of Shares		Weighted Average Grant Date Fair Value
Nonvested shares subject to restricted stock units outstanding at December 31, 2012	425		$	14.37
Granted	173		42.90
Forfeited	(2	)	40.03
Vested	(214	)	13.15
Nonvested shares subject to restricted stock units outstanding at December 31, 2013	382		$	27.81

Stock-based compensation expense related to stock options, restricted stock units and restricted stock awards

Stock-based compensation expense related to stock options, restricted stock units and restricted stock awards is included in the following line items in the accompanying Consolidated Statement of Operations for the years ended December 31, 2013, 2012, and 2011 (in thousands):



	Years Ended December 31,
	2013		2012		2011
Cost of revenue	$	2,207	$	1,660	$	581
Sales and marketing	9,866		3,982		1,121
Research and development	2,052		949		755
General and administrative	6,715		5,616		2,045
Total	$	20,840	$	12,207	$	4,502