Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2016

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

Schedule of share-based compensation, stock options, activity

The following table summarizes the Company’s stock option activity and related information as of and for the six months ended June 30, 2016 (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, 2015	3.6		$	27.52
Exercised	(0.4	)	14.10
Expired	(0.2	)	33.80
Balance as of June 30, 2016	3.0		$	28.98	1.8	$	7.3

As of June 30, 2016:
Vested and expected-to-vest options	3.0		$	28.99	1.8	$	7.2
Exercisable options	3.0		$	29.37	1.7	$	6.4

Schedule of nonvested share activity

The following table summarizes the Company’s RSU, RSA, and PSA activity and related information as of and for the six months ended June 30, 2016 (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, 2015	18.6		$	22.71
RSUs granted ⁽¹⁾⁽³⁾	6.9		24.68
RSUs assumed	0.2		24.76
PSAs granted⁽²⁾⁽³⁾	0.7		23.62
PSAs assumed	0.2		25.09
RSUs vested	(5.5	)	22.37
RSAs vested	(0.8	)	20.76
PSAs vested	(0.6	)	21.61
RSUs canceled	(0.7	)	23.15
PSAs canceled	(0.4	)	21.81
Balance as of June 30, 2016	18.6		$	23.73	1.4	$	419.3

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⁽¹⁾	Includes service-based and market-based RSUs granted under the 2015 Plan according to its terms.

⁽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 0.5 million shares. Depending on achievement of such performance goals, the range of shares that could be issued under these awards is 0 to 0.7 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. On April 28, 2016, the Company declared a cash dividend of $0.10 per share of common stock, or $38.1 million in the aggregate, to stockholders of record on June 1, 2016, which was paid on June 22, 2016.

Estimates of weighted average fair value per share under employee purchase plan and stock option plan

The weighted-average assumptions used and the resulting estimates of fair value for ESPP and market-based RSUs during the six months ended June 30, 2016 and June 30, 2015 were as follows:



	Six Months Ended June 30,
	2016	2015
ESPP ⁽¹⁾:
Volatility	35%	30%
Risk-free interest rate	0.5%	0.1%
Expected life (years)	0.5	0.5
Dividend yield	1.7%	1.9%
Weighted-average fair value per share	$5.95	$5.23

Market-based RSUs ⁽²⁾:
Volatility	36%	34%
Risk-free interest rate	1.2%	1.4%
Dividend yield	1.7%	1.8%
Weighted-average fair value per share	$14.71	$14.97

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⁽¹⁾	The Black-Scholes-Merton option-pricing model is utilized to estimate the fair value of shares issuable under the ESPP.

⁽²⁾

The fair value of market-based RSUs utilizes a Monte Carlo valuation methodology. The Company amortizes the fair value of these awards over the derived service period adjusted for estimated forfeitures for each separately vesting tranche of the award. Provided that the derived service is rendered, the total fair value of the market-based RSUs at the date of grant is recognized as compensation expense even if the market condition is not achieved. However, the number of shares that ultimately vest can vary significantly with the performance of the specified market criteria.

Schedule of employee service share-based compensation, allocation of recognized period costs

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,
	2016		2015		2016		2015
Cost of revenues - Product	$	1.5	$	1.5	$	3.4	$	3.2
Cost of revenues - Service	4.3		3.8		7.8		7.2
Research and development	29.5		32.5		61.8		63.2
Sales and marketing	13.8		13.4		23.2		19.2
General and administrative	6.5		7.7		11.2		12.1
Total	$	55.6	$	58.9	$	107.4	$	104.9

Disclosure of share-based compensation arrangements by share-based payment award

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



	Three Months Ended June 30,				Six Months Ended June 30,
	2016		2015		2016		2015
Stock options	$	1.1	$	1.5	$	2.3	$	3.7
RSUs, RSAs, and PSAs	50.4		53.3		97.2		93.9
ESPP	4.1		4.1		7.9		7.3
Total	$	55.6	$	58.9	$	107.4	$	104.9

Schedule of unrecognized compensation cost, nonvested awards

The following table presents unrecognized compensation cost, adjusted for estimated forfeitures, recognized over a weighted-average period related to unvested stock options, RSUs, RSAs, and PSAs as of June 30, 2016 (in millions, except years):



	Unrecognized Compensation Cost		Weighted Average Period (In Years)
Stock options	$	0.3	0.3
RSUs, RSAs, and PSAs	$	252.0	1.9