Percentage of discount to employees on purchase of common stock under employee stock purchase plan.

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Percentage Of Service Agreement Payment

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Period of vesting for share-based compensation awards.

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expected To Vest Intrinsic Value

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Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Expected To Vest Number

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Share based compensation arrangement by share based payment award service agreement period description.

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Stock based compensation expense expected to be recorded.

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- Definition

Aggregate number of common shares reserved for future issuance.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Represents the compensation cost capitalized during the period arising from equity-based compensation arrangements (for example, shares of stock, units, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Unrecognized cost of unvested options awarded to employees as compensation.

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Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Number of options outstanding, including both vested and non-vested options.

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Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Stockholders' Equity and Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Sep. 25, 2014	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Feb. 07, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Common stock authorized		500,000,000	500,000,000
Number of Shares outstanding		1,840,000	2,315,000
Unrecognized compensation costs		$ 7.6
Unrecognized compensation costs, weighted average period		2 years 8 months 12 days
Percentage of discount allowed to employee to purchase common stock	15.00%
Number of shares authorizes for issuance		3,823,000	4,400,000
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of shares authorizes for issuance	1,785,021,000
Internal-Use Software [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Capitalized software development costs excluded from stock based compensation		$ 2.4	$ 1.6	$ 1.2
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Percentage of service condition met		25.00%
Service agreement period description		The service condition is a time-based condition met over a period of four years, with 25% met after one year, and then in equal monthly or quarterly installments over the succeeding three years, or over a period of four years, with equal quarterly installments over those four years.
The total stock-based compensation expense expected to be recorded		$ 150.1
Weighted average period of RSU		2 years 8 months 12 days
Number of RSUs expected to vest					2,000,000
Aggregate intrinsic value of RSUs expected to vest					$ 248.9
Total fair value of RSUs vested		$ 65.0	$ 48.6	$ 24.0
Number of shares authorizes for issuance		1,983,000	2,085,000
Common Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Weighted-average grant date fair value of options granted		$ 51.48	$ 24.56	$ 16.97
Number of shares authorizes for issuance		1,840,000	2,315,000
Maximum [Member] \| RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Period of service condition met		4 years
Minimum [Member] \| RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Period of service condition met		1 year
2007 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of shares available for issuance		0
2007 Equity Incentive Plan [Member] \| Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of Shares outstanding		1,300,000
2007 Equity Incentive Plan [Member] \| RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of Shares outstanding		0
2007 Equity Incentive Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of years fixed for each option		10 years
2014 Stock Option and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Percentage of common stock outstanding	5.00%
2014 Stock Option and Incentive Plan [Member] \| Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of shares available for issuance	1,973,551
Number of Shares outstanding		563,000
2014 Stock Option and Incentive Plan [Member] \| RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of Shares outstanding		2,000,000
2014 Stock Option and Incentive Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Number of years fixed for each option	10 years