Employee Stock Plans - Stock Option Activity Table (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Shares outstanding	827,045	1,520,917
Shares outstanding, weighted-average exercise price	$ 76.66	$ 73.68
Shares exercised	(669,180)
Shares exercised, weighted-average exercise price	$ 70.21
Shares forfeited	(24,692)
Shares forfeited, weighted-average exercise price	$ 68.37
Shares exercisable	390,815
Shares exercisable, weighted-average exercise price	$ 72.00
Shares outstanding, weighted-average remaining contractual life	77 months
Shares exercisable, weighted-average remaining contractual life	63 months
Shares outstanding, aggregate intrinsic value	$ 47,893
Shares exercisable, aggregate intrinsic value	22,337
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	26,614	$ 8,211	$ 9,346
Proceeds from exercise of stock options	$ 46,982	$ 21,037	$ 16,911

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Amount of cash inflow from exercise of option under share-based payment arrangement.

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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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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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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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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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

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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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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for fully vested and expected to vest exercisable or convertible options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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

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