Stock Plans - Summary of Stock Option Activity (Details)	9 Months Ended
Sep. 30, 2021 $ / shares shares
Shares
Outstanding, beginning balance (in shares) \| shares	283,998
Exercised (in shares) \| shares	(58,234)
Forfeited (in shares) \| shares	(210)
Outstanding, ending balance (in shares) \| shares	225,554
Exercisable (in shares) \| shares	224,980
Weighted Average Exercise Price (dollars per share)
Outstanding, beginning balance (dollars per share) \| $ / shares	$ 46.23
Exercised (dollars per share) \| $ / shares	45.84
Forfeited (dollars per share) \| $ / shares	43.75
Outstanding, ending balance (dollars per share) \| $ / shares	46.34
Exercisable (dollars per share) \| $ / shares	$ 46.33

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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- Definition

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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- Definition

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

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

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- Definition

Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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- Definition

Number of share options (or share units) exercised during the current period.

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