Employee Benefit Plans

Equity Incentive Plans

The Company has stock-based compensation plans pursuant to which it has granted stock options, restricted stock units (“RSUs”), and performance share awards (“PSAs”). The Company also maintains the Company's 2008 Employee Stock Purchase Plan (the “ESPP”) for all eligible employees.

As of June 30, 2017, 35.5 million and 12.4 million shares were available for future issuance under the Company's 2015 Equity Incentive Plan (the "2015 Plan") and ESPP, respectively, which includes an additional 23.0 million shares under the 2015 Plan and 9.0 million shares under the ESPP that were approved by the Company's stockholders in May 2017.

Stock Option Activities

The following table summarizes the Company’s stock option activity and related information as of and for the six months ended June 30, 2017 (in millions, except for per share amounts and years):



	Outstanding Options
	Number of Shares		Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term (In Years)	Aggregate Intrinsic Value
Balance as of December 31, 2016	2.4		$	29.20
Exercised	(0.4	)	16.63
Expired/canceled	(0.7	)	30.83
Balance as of June 30, 2017	1.3		$	32.46	1.2	$	4.8

As of June 30, 2017:
Vested and expected-to-vest options	1.3		$	32.46	1.2	$	4.8
Exercisable options	1.2		$	33.63	0.9	$	3.6

Restricted Stock Unit, Restricted Stock Award, and Performance Share Award Activities

The Company’s RSU, restricted stock award ("RSA"), and PSA activity and related information as of and for the six months ended June 30, 2017 were as follows (in millions, except per share amounts and years):



	Outstanding RSUs, RSAs, and PSAs
	Number of Shares		Weighted Average Grant-Date Fair Value per Share		Weighted Average Remaining Contractual Term (In Years)	Aggregate Intrinsic Value
Balance as of December 31, 2016	20.9		$	24.05
RSUs granted ⁽¹⁾⁽³⁾	5.8		27.55
PSAs granted⁽²⁾⁽³⁾	0.6		27.37
RSUs vested	(5.6	)	23.87
RSAs vested	(0.3	)	22.70
PSAs vested	(0.6	)	24.41
RSUs canceled	(1.0	)	24.08
PSAs canceled	(0.3	)	24.77
Balance as of June 30, 2017	19.5		$	25.08	1.3	$	542.8

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⁽¹⁾	Includes service-based and market-based RSUs.

⁽²⁾

The number of shares subject to PSAs granted represents the aggregate maximum number of shares that may be issued pursuant to the award over its full term. The aggregate number of shares subject to these PSAs that would be issued if performance goals determined by the Compensation Committee are achieved at target is 0.4 million shares. Depending on achievement of such performance goals, the range of shares that could be issued under these awards is 0 to 0.6 million shares.

⁽³⁾

The grant date fair value of RSUs and PSAs were reduced by the present value of dividends expected to be paid on the underlying shares of common stock during the requisite and derived service period as these awards are not entitled to receive dividends until vested. During the six months ended June 30, 2017, the Company declared a quarterly cash dividend of $0.10 per share of common stock on January 26, 2017 and April 25, 2017.

Employee Stock Purchase Plan

The ESPP is implemented in a series of offering periods, each currently six months in duration, or such other period as determined by the Board. Employees purchased approximately 1.5 million and 1.3 million shares of common stock through the ESPP at an average exercise price of $19.21 and $20.06 per share during the six months ended June 30, 2017 and June 30, 2016, respectively. There were no stock purchases under the ESPP during the three months ended June 30, 2017 and June 30, 2016.

Share-Based Compensation Expense

Share-based compensation expense associated with stock options, RSUs, RSAs, PSAs, and ESPP was recorded in the following cost and expense categories in the Condensed Consolidated Statements of Operations (in millions):



	Three Months Ended June 30,				Six Months Ended June 30,
	2017		2016		2017		2016
Cost of revenues - Product	$	1.4	$	1.5	$	2.3	$	3.4
Cost of revenues - Service	5.3		4.3		9.6		7.8
Research and development	14.1		29.5		48.9		61.8
Sales and marketing	16.3		13.8		31.6		23.2
General and administrative	7.0		6.5		13.7		11.2
Total	$	44.1	$	55.6	$	106.1	$	107.4

The following table summarizes share-based compensation expense by award type (in millions):



	Three Months Ended June 30,				Six Months Ended June 30,
	2017		2016		2017		2016
Stock options	$	0.2	$	1.1	$	0.3	$	2.3
RSUs, RSAs, and PSAs	40.1		50.4		97.9		97.2
ESPP	3.8		4.1		7.9		7.9
Total	$	44.1	$	55.6	$	106.1	$	107.4

As of June 30, 2017, the unrecognized compensation cost related to unvested stock options, RSUs, RSAs, and PSAs was $332.5 million to be recognized over a weighted-average period of 1.7 years.