Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2016

Equity [Abstract]

Compensation Costs Included in Statement of Income for All Stock-based Compensation Arrangements

The compensation cost that has been included in the statement of operations for the Company’s stock-based compensation plans was as follows (in thousands):

	Year Ended December 31,
	2016			2015			2014
Sales, marketing and administrative expense	$	25,466		$	24,817		$	31,514
Research and development expense		1,231			1,157			1,841
Cost of goods sold		227			229			332
Stock-based compensation expense before taxes		26,924			26,203			33,687
Related income tax benefits		(10,770	)		(10,481	)		(13,475	)
Stock-based compensation expense, net of taxes	$	16,154		$	15,722		$	20,212

Summary of Restricted Stock Units

The total fair value of RSUs that vested during the year ended December 31, 2016, 2015, and 2014 was $31.2 million, $39.0 million and $27.5 million, respectively.

Following is a summary of RSU activity for the year ended December 31, 2016 (in thousands, except per share amounts):

				Weighted
				Average
	Number of			Grant Date
	Shares			Fair Value
Outstanding at December 31, 2015		1,349		$	31.82
Granted		529			46.06
Vested		(627	)		25.54
Forfeited		(155	)		36.52
Outstanding at December 31, 2016		1,096		$	41.16

For the majority of RSUs, shares are issued on the vesting dates net of the amount of shares needed to satisfy statutory tax withholding requirements to be paid by the Company on behalf of the employees. The total shares withheld related to vested RSUs were approximately 227,000, 330,000, and 29,000 in 2016,2015, and 2014, respectively, and were based on the value of the awards on their vesting dates as determined by the Company’s closing stock price. Total payments for the employees’ tax obligations to the taxing authorities related to vesting RSUs were $11.4 million, $15.4 million and $1.1 million in 2016, 2015 and 2014, respectively.

Schedule of Performance-Based Restricted Stock Units

Following is a summary of PRSU activity for the year ended December 31, 2016 (in thousands, except per share amounts):

				Maximum Number
	Shares			of Shares Eligible to be Issued			Average Grant Date Fair Value
Outstanding at December 31, 2015		803			1,357		$	46.42
Awarded at target		392			651			45.11
Vested		(145	)		(179	)		39.78
Forfeited		(179	)		(276	)		44.22
Outstanding at December 31, 2016		871			1,553		$	46.76

Summary of Stock Option Activity under All Stock Plans

						Weighted-Average
						Remaining
				Weighted		Contractual		Aggregate
				Avg. Exercise		Term		Intrinsic
	Shares			Price		(Years)		Value
Outstanding at December 31, 2015		1,970		$	34.91		2.99	$	37,820
Exercised		(1,556	)		34.95
Cancelled		(4	)		18.92
Outstanding at December 31, 2016		410			34.93		2.47	$	13,292
Exercisable at December 31, 2016		410		$	34.93		2.47	$	13,292
Vested or expected to vest at December 31, 2016		410		$	34.93		2.47	$	13,292

Weighted Average Assumptions Used to Estimate Fair Value of Stock Options Granted and Stock Purchase Rights under ESPP

The weighted average assumptions used to estimate the fair value of stock options granted and stock purchase rights under the ESPP are as follows:

	Year Ended December 31,
	2016			2015			2014
ESPP
Volatility		29	%		40	%		46	%
Expected term (years)		0.5			1.2			1.3
Risk free interest rate		0.4	%		0.2	%		0.2	%
Expected dividend yield		—	%		—	%		—	%

Common Stock Reserved for Future Issuance

The following table summarizes common shares reserved for issuance on exercise or conversion at December 31, 2016(in thousands):

Issued and outstanding stock options	410
Issued and outstanding RSUs and PRSUs	2,150
Available for issuance under the ESPP	1,398
Available for future grant	4,383
2017 Notes	1,954
2017 Warrants	19,106
2021 Notes	14,396
2021 Warrants	32,596
Total shares reserved for future issuance	76,393