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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Section 50
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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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

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

+ References

No definition available.

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- Definition

Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

+ References

No definition available.

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- Definition

Percentage of vesting of share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
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- Definition

Value, before forfeitures, of stock or other type of equity granted of any equity-based compensation plan other than an employee stock ownership plan (ESOP).

+ References

No definition available.

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Stockholders' Equity - The 2017 Plan, Additional Information (Details) - USD ($)							3 Months Ended
	Oct. 31, 2017	Oct. 24, 2017	Sep. 18, 2017	Sep. 12, 2017	Sep. 11, 2017	Sep. 08, 2017	Oct. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense					$ 0
2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)		1,500
Options granted, exercise price (in dollars per share)		$ 29.02
Expiration period		10 years
Fair value of option granted		$ 43,500
Share-based compensation							$ 792,000
Compensation cost not yet recognized	$ 7,200,000						$ 7,200,000
2017 Plan \| Controller
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)						40,000
Options granted, exercise price (in dollars per share)						$ 49.93
Expiration period						10 years
Vesting percentage						25.00%
Fair value of option granted						$ 1,990,000
Stock based compensation expense						$ 196,000
2017 Plan \| Chief Financial Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)				150,000
Options granted, exercise price (in dollars per share)				$ 36.00
Expiration period				10 years
Vesting percentage				25.00%
Fair value of option granted				$ 5,400,000
Stock based compensation expense				$ 530,000
2017 Plan \| Consultant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)			15,000
Options granted, exercise price (in dollars per share)			$ 27.56
Expiration period			10 years
Fair value of option granted	$ 576,000		$ 413,000
Stock based compensation expense			$ 66,000
End of one year \| 2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		25.00%
Employee Stock Option \| 2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period							10 years
Employee Stock Option \| End of one year \| 2017 Plan \| Consultant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			33.33%
Employee Stock Option \| Monthly after year one \| 2017 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage		2.08%
Employee Stock Option \| Monthly after year one \| 2017 Plan \| Controller
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage						2.08%
Employee Stock Option \| Monthly after year one \| 2017 Plan \| Chief Financial Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage				2.08%
Employee Stock Option \| Monthly after year one \| 2017 Plan \| Consultant
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage			2.78%