Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2020

Share-based Payment Arrangement [Abstract]

The following table summarizes the Company’s RSU, RSA, and PSA activity and related information as of and for the year ended December 31, 2020 (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 at December 31, 2019	17.5	$	25.30
Granted(1)(2)	8.4	22.13
Awards assumed upon the acquisition of 128 Technology(2)	3.1	20.15
Vested(3)	(6.7)	25.92
Canceled	(2.4)	24.38
Balance at December 31, 2020	19.9	$	23.05	1.3	$	447.7

As of December 31, 2020
Vested and expected-to-vest RSUs, RSAs, and PSAs	18.6	$	23.04	1.3	$	419.1

________________________________

(1)Includes 7.1 million service-based, 0.9 million performance-based, and 0.4 million market-based RSUs and PSAs, as applicable. The number of shares subject to performance-based and market-based conditions represents the aggregate maximum number of shares that may be issued pursuant to the award over its full term. The grant date fair value of RSUs and PSAs was 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.

(2)The weighted-average grant-date fair value of RSUs, RSAs, and PSAs granted and assumed or substituted during 2020, 2019, and 2018 was $21.59, 25.26, and 25.33, respectively. The grant date fair value of RSUs and PSAs was 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 2020, the Company declared a quarterly cash dividend of $0.20 per share of common stock on January 27, 2020, April 28, 2020, July 28, 2020 and October 27, 2020.

(3)Total fair value of RSUs, RSAs, and PSAs vested during 2020, 2019, and 2018 was $174.7 million, $170.0 million, and $200.5 million, respectively.

Shares Available for Grant

The following table presents the stock activity and the total number of shares available for grant under the 2015 Plan (in millions):


			Number of Shares
Balance as of December 31, 2019			16.6
Additional shares authorized			—
RSUs and PSAs granted(*)			(8.4)
RSUs and PSAs canceled(*)			3.9

Balance as of December 31, 2020			12.1

________________________________

(*) In May 2019, the 2015 Plan was amended, and the amendment removed the fungible share adjustment used to determine shares available for issuance. Under the original terms of the 2015 Plan, RSUs and PSAs with a per share or unit purchase price lower than 100% of the fair market value of the Company's common stock on the day of the grant were counted against shares authorized under the plan as two and one-tenth shares of common stock ("the prior fungible rate") for each share subject to such award. Pursuant to the amendment, beginning on May 14, 2019, each share award granted under the 2015 Plan reduces the share reserve by one share and all share awards granted on May 14, 2019 and thereafter that are later forfeited, canceled or terminated are returned to the share reserve in the same manner. During 2020, among the total 3.9 million of canceled shares, 3.5 million shares represent the shares returned to the share reserve at the prior fungible rate. The number of shares subject to PSAs granted represents the maximum number of shares that may be issued pursuant to the award over its full term.

Schedule Of Share-based Payment Award, Stock Options and Employee Stock Purchase Plan, Valuation Assumptions

The weighted-average assumptions used and the resulting estimates of fair value for ESPP purchase rights and market-based RSUs were as follows:


	Years Ended December 31,
	2020	2019	2018
ESPP Purchase Rights:
Volatility	31%	27%	29%
Risk-free interest rate	0.8%	2.1%	1.9%
Expected life (years)	1.3	1.2	1.2
Dividend yield	3.3%	2.9%	2.7%
Weighted-average fair value per share	$6.34	$6.65	$6.93

Market-based RSUs:
Volatility	25%	25%	28%
Risk-free interest rate	1.3%	2.4%	2.4%
Dividend yield	3.3%	2.8%	2.6%
Weighted-average fair value per share	$26.32	$27.32	$28.39

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 purchase rights was recorded in the following cost and expense categories in the Company's Consolidated Statements of Operations (in millions):


	Years Ended December 31,
	2020		2019		2018
Cost of revenues - Product	$	5.4	$	5.7	$	6.3
Cost of revenues - Service	15.8		17.3		18.0
Research and development	78.8		94.0		120.6
Sales and marketing	58.2		56.0		51.1
General and administrative	31.4		29.2		21.1
Total	$	189.6	$	202.2	$	217.1

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award

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


	Years Ended December 31,
	2020		2019		2018
Stock options	$	7.3	$	7.7	$	0.4
RSUs, RSAs, and PSAs	162.6		176.5		198.2
ESPP Purchase Rights	19.7		18.0		18.5
Total	$	189.6	$	202.2	$	217.1