Employee Benefit Plan - Additional Information (Detail) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Maximum employee contribution to 401k	50.00%
Employer matching contribution percent for plan participant	50.00%	50.00%
Defined Contribution Plan, Sponsor Location [Extensible List]	country:US	country:US
Defined Contribution Plan, Tax Status [Extensible List]	us-gaap:QualifiedPlanMember	us-gaap:QualifiedPlanMember
Maximum contribution by participant that employer will match at 50%	12.00%	6.00%
Maximum annual contribution by employer	$ 5,000	$ 3,000
Employer contribution to the plan	$ 4,100,000	$ 2,400,000	$ 2,100,000

Annual maximum contribution to participant 401k plan.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

No definition available.

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Amount of discretionary contributions made by an employer to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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Period Type:	duration

Percentage employer matches of the employee's percentage contribution matched.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Indicates location of employer sponsoring defined contribution plan designed to provide retirement benefits.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	srt-types:extensibleListItemType
Balance Type:	na
Period Type:	instant

Indicates tax status of defined contribution plan designed to provide retirement benefits.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	srt-types:extensibleListItemType
Balance Type:	na
Period Type:	instant