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Share based compensation arrangement by share based payment award maximum amount payable in cash per employee.

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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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Exercise price per share or per unit of warrants or rights outstanding.

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Number of warrants or rights outstanding.

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Price of the entity's common stock which would be required to be attained for the conversion feature embedded in the debt instrument to become effective.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

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Date the equity-based award expires, in CCYY-MM-DD format.

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The highest quantity of shares an employee can purchase under the plan per period.

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Number of additional shares authorized for issuance under an established share-based compensation plan.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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Purchase price of common stock expressed as a percentage of its fair value.

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Stockholders' Equity (Deficit) - Additional Information (Detail)						3 Months Ended		6 Months Ended
	Jul. 08, 2019 $ / shares shares	Oct. 31, 2018 $ / shares shares	Oct. 01, 2016 d $ / shares shares	Mar. 18, 2016 d	Jun. 09, 2015 USD ($) shares	Jun. 30, 2019 USD ($) $ / shares shares	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) d Incentive_Plan $ / shares shares	Jun. 30, 2018 USD ($)	Mar. 26, 2019 shares	Dec. 31, 2018 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants, exercise price \| $ / shares		$ 7.155
Preferred stock, par value \| $ / shares						$ 0.0001		$ 0.0001			$ 0.0001
Preferred stock, shares authorized						24,984,166		24,984,166			24,984,166
Number of stock incentive plans \| Incentive_Plan								2
Stock incentive plan expiration date								Aug. 31, 2015
Award authorized by board										800,000
Compensation costs associated \| $						$ 23,000	$ 103,904	$ 46,000	$ 207,808
Number of warrants						120,000		120,000
Warrants, expiration date								Oct. 01, 2021
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		700,000
Stock issued during theperiod share warrants								120,000
Note And Warrant Purchase Agreement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants, exercise price \| $ / shares						$ 12.00		$ 12.00
Number of warrants						65,625		65,625
Warrants, expiration date								Jul. 21, 2021
Note And Warrant Purchase Agreement [Member] \| Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants, exercise price \| $ / shares	$ 5.756
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	196,135
Note And Warrant Purchase Agreement [Member] \| Second Amendment Agreement [Member] \| Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants, exercise price \| $ / shares	$ 5.756
Warrants, expiration date	Jul. 12, 2024
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	196,135
2015 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award authorized by board					450,000
Series AA-2 Convertible Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, par value \| $ / shares						$ 0.0001		$ 0.0001
Preferred stock, shares authorized						7,223,145		7,223,145
Series AA-2 Convertible Preferred Stock [Member] \| Penelope Mining LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of trading days \| d								20
Series AA-1 Convertible Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, par value \| $ / shares						$ 0.0001		$ 0.0001
Preferred stock, shares authorized						8,427,004		8,427,004
Preferred stock Liquidation preference accretion rate								8.00%
Minimum [Member] \| Series AA-2 Convertible Preferred Stock [Member] \| Penelope Mining LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing price of common stock \| $ / shares								$ 15.12
Notes Payable, Other Payables [Member] \| Epsilon Acquisitions, LLC [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants, exercise price \| $ / shares			$ 3.52			$ 3.52		$ 3.52
Warrant Expiration Date								Oct. 01, 2021
Warrant right exercise price description								Warrant shall be the number determined by multiplying 120,000 by a fraction, (a) the numerator of which is the aggregate principal amount of advances that have been extended to the OME by Epsilon pursuant to the Restated Note Purchase Agreement on or after the date of the Warrant and prior to the date of such failure and (b) the denominator of which is $3.0 million.
Number of trading days \| d			75	75
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			120,000
Incentive Stock Options [Member] \| 2015 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award authorized by board					450,000
Additional shares authorized for stock-based compensation								200,000
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock and warrants sold		700,000
Repurchases of common stock, shares		700,000
Purchase price of repurchased shares \| $ / shares		$ 7.155
Warrants, exercise price \| $ / shares		$ 7.155
Warrant Expiration Date		Nov. 02, 2023
Warrant right exercise price description		The warrants have an exercise price of $7.155 per share of common stock and are exercisable in accordance with their terms at any time on or before the close of business on November 2, 2023.
Common Stock [Member] \| Incentive Stock Options [Member] \| 2015 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of incentive option granted								With respect to each grant of an ISO to a participant who is not a ten percent stockholder, the exercise price shall not be less than the fair market value of a share on the date the ISO is granted. With respect to each grant of an ISO to a participant who is a ten percent stockholder, the exercise price shall not be less than one hundred ten percent (110%) of the fair market value of a share on the date the ISO is granted.
Maximum aggregate number of Shares with respect to one or more Awards that may be granted to any one person during any calendar year					83,333
Maximum aggregate amount of cash that may be paid in cash to any person during any calendar year \| $					$ 2,000,000
Common Stock [Member] \| Incentive Stock Options [Member] \| Minimum [Member] \| 2015 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Eligible employee threshold percentage								10.00%
Purchase price of common stock percentage								110.00%