Defined Contribution Plan, Employee Contributions, Percentage of Eligible Compensation

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- Definition

Number of shares available to issuance under the employee stock purchase plan.

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- Definition

Share based compensation employee stock purchase plan contribution percentage.

+ References

No definition available.

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- Definition

The number of share available for issuance.

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- Definition

Amount of cost for defined contribution plan.

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Amount of cost to be recognized for option under share-based payment arrangement.

+ References

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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

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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No definition available.

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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- Definition

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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- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

No definition available.

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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

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Share-Based Compensation and Employee Benefit Plans - Textual (Details) - USD ($) shares in Thousands	12 Months Ended
	Dec. 26, 2020	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total intrinsic value of stock options exercised	$ 420,000	$ 51,000	$ 384,000
Unrecognized compensation cost - option	$ 0
Shares purchased under ESPP	91	72	13
Employee stock purchase plan available	1,500	236
Percentage of contribution for annual compensation	100.00%
Percentage of match of all employee contribution	50.00%
Total matching contribution to plan	$ 2,315,000	$ 1,317,000	$ 1,118,000
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of match on employee salary	6.00%
Onto Innovation 2020 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Price of common stock as percentage of fair market value	85.00%
Onto Innovation 2020 Employee Stock Purchase Plan [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Eligible compensation deduction percentage on pay for purchase of common stock	10.00%
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized compensation cost related to restricted stock units granted	$ 19,135,000
Unrecognized compensation cost related to restricted stock units, weighted average period	1 year 8 months 12 days
Onto Innovation 2020 Stock Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share authorized available for grants	3,613
Period of vesting	3 years
Options expiration period	10 years
Shares of common stock available for issuance pursuant to future grants	3,555
Onto Innovation 2020 Stock Plan [Member] \| Restricted Stock Units (RSUs) [Member] \| Employees [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period of vesting	3 years
Onto Innovation 2020 Stock Plan [Member] \| Restricted Stock Units (RSUs) [Member] \| Directors [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period of vesting	1 year