Represents the period of historical option activity considered to determine expected option life.

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Represents the maximum allowable contribution by eligible employees as a percentage of base earnings.

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Share based compensation arrangement by share based payment award maximum employee contribution in calendar year.

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Represents the common stock purchase price as a percentage of fair market value.

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The period of time, from the grant date until the time at which the share-based [option] award expires.

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

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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.

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Amount of cash outflow to satisfy grantee's tax withholding obligation for award under share-based payment arrangement.

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

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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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

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Stock-Based Compensation - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cash received from stock option exercises	$ 3,300,000	$ 10,700,000	$ 5,100,000
Cash used for shares withheld to satisfy employee tax obligations for RSUs and PRSUs converted	$ 7,700,000	6,200,000	$ 5,900,000
Shares authorized for future grant under stock plan (in shares)	4,000,000.0
Non-qualified stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options vesting period	3 years
Options expiration period	10 years
Period of historical option activity considered to determine expected option life			10 years
Unrecognized compensation cost	$ 3,800,000	$ 1,500,000
Non-qualified stock options \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period over which unrecognized compensation costs will be recognized	1 year
Non-qualified stock options \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period over which unrecognized compensation costs will be recognized	3 years
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares outstanding	543,391	400,000	500,000	500,000
Unrecognized compensation cost	$ 8,800,000
RSUs \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period over which unrecognized compensation costs will be recognized	1 year
RSUs \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period over which unrecognized compensation costs will be recognized	3 years
PRSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares outstanding	294,941	300,000	300,000	400,000
Unrecognized compensation cost	$ 1,700,000
Performance period	3 years	3 years	3 years
Shares authorized for issuance under stock plan	3,300,000
PRSUs \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period over which unrecognized compensation costs will be recognized	1 year
Performance period	3 years
PRSUs \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Period over which unrecognized compensation costs will be recognized	3 years
Employee stock purchase plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum contribution by eligible employees as percentage of base earnings (as a percent)	10.00%
Maximum contribution by eligible employees in a calendar year	$ 25,000
Common stock purchase price as percentage of fair market value (as a percent)	85.00%
Shares purchased under employee stock purchase plan (in shares)	35,000	48,236