Grant date fair value of the options granted during the period.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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- Definition

Aggregate number of common shares reserved for future issuance.

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

+ References

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

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- Definition

General descriptive information regarding an arrangement under which employees and directors receive: (a) awards of equity shares, equity share options, or other equity instruments; or (b) the entity incurs liabilities to them: (1) in amounts based, at least in part, on the price of the entity's shares or other equity instruments; or (2) that require or may require settlement by issuance of the entity's shares. Such an arrangement is usually provided to employees and directors to compensate them, provide performance incentives to them, and to attract or retain their services. May also include pertinent information particular to a plan that is not elsewhere specified in the taxonomy.

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- Definition

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).

+ References

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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- Definition

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.

+ References

No definition available.

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- Definition

Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

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- Definition

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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- Definition

Gross number of share options (or share units) granted during the period.

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No definition available.

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

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Stock-Based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options outstanding	5,487,100		5,487,100		5,524,399
Number of options outstanding, granted			712,500
RSU awards vesting, description			At vesting, each outstanding RSU will be exchanged for one share of the Company’s Common Stock. RSU recipients may elect to net share settle upon vesting, in which case the Company pays the employee’s income taxes due upon vesting and withholds a number of shares of Common Stock of equal value. RSU awards generally vest subject to the satisfaction of service requirements or the satisfaction of both service requirements and achievement of certain performance targets.
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 1,017,065	$ 858,005	$ 1,807,500	$ 1,758,664
Grant date fair value of the options granted	7,580,360	1,944,007	8,137,249	2,292,906
Intrinsic value of options exercised	6,806,594	350,674	8,122,294	350,674
Unrecognized pre-tax compensation expense	11,164,000		$ 11,164,000
Weighted average period to recognize pre-tax compensation expense			3 years 4 months 24 days
Dividend yield			0.00%
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of restricted stock units outstanding, granted			1,403,888
Stock-based compensation expense	1,584,283	$ 598,808	$ 3,511,381	$ 1,790,690
Weighted average period to recognize pre-tax compensation expense			3 years 3 months 18 days
Unrecognized pre-tax compensation expense	$ 9,551,860		$ 9,551,860
2004 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserve for issuance	1,440,218		1,440,218
2004 Equity Incentive Plan \| Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options outstanding	1,440,218		1,440,218
2013 Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserve for issuance	5,654,798		5,654,798
2013 Incentive Plan \| Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options outstanding	3,270,048		3,270,048
Number of options outstanding, granted	517,500		517,500
2013 Incentive Plan \| Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of restricted stock units outstanding	2,049,333		2,049,333
Number of restricted stock units outstanding, granted	1,398,429		1,401,888
Outside Of Equity Compensation Plans
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserve for issuance	776,834		776,834
Outside Of Equity Compensation Plans \| Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options outstanding, granted	148,000		195,000
Outside Of Equity Compensation Plans \| Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares reserve for issuance	2,000		2,000
Number of restricted stock units outstanding, granted	2,000		2,000