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Share-based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended
	Aug. 31, 2018	Jun. 30, 2016	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to unvested stock options			$ 8.5
Expected weighted average period for recognition of compensation expense			1 year 9 months 18 days
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option vested percentage			25.00%
Share-based compensation arrangement by share-based payment award, award vesting period			36 months
Share-based compensation arrangement by share-based payment award, expiration period			10 days
Restricted Stock Units (RSUs) | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs granted	332,193	364,726
Number of common stock to be received for each RSUs			1
RSUs grant date fair value per unit	$ 245,782
Shares withheld to satisfy tax withholding obligations	86,411
2008 Omnibus Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock authorized			19,089,794
Shares available for future grant			6,979,777
Maximum [Member] | Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period			36 months
Minimum [Member] | Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period			12 months

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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 grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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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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