Subsequent Events - Proceeds from Sale of Common Stock (Details) - USD ($) $ / shares in Units, $ in Millions		1 Months Ended
Apr. 07, 2020	Apr. 30, 2020
Subsequent Events
Gross proceeds from sale of common stock and warrants excluding the proceeds from exercise of the warrants, if any		$ 5.0
Pillar Investment Entities
Subsequent Events
Ownership percentage		19.00%
Subsequent Events \| Future plans \| Pillar Investment Entities
Subsequent Events
Ownership percentage	19.99%
Subsequent Events \| Pillar Investment Entities
Subsequent Events
Stock issued (in shares)	3,039,514
Shares of common stock that may be purchased upon exercise of warrants	3,039,514
Warrant exercise price (per share)	$ 2.28
Gross proceeds from sale of common stock and warrants excluding the proceeds from exercise of the warrants, if any	$ 5.0
Combined purchase price (per share)	$ 1.645
Stock price underlying warrants (per share)	$ 0.125
Subsequent Events \| Pillar Investment Entities \| Future plans
Subsequent Events
Stock issued (in shares)	2,747,252
Shares of common stock that may be purchased upon exercise of warrants	1,373,626
Warrant exercise price (per share)	$ 2.71
Gross proceeds from sale of common stock and warrants excluding the proceeds from exercise of the warrants, if any	$ 5.0
Number of common warrants	0.5
Stock price (in dollars per share)	$ 3.01
Number of consecutive trading days	20 days
Subsequent Events \| Pillar Investment Entities \| Future plans \| Common stock warrants
Subsequent Events
Combined purchase price (per share)	$ 1.82
Subsequent Events \| Pillar Investment Entities \| Future plans \| Pre-funded Warrants
Subsequent Events
Warrant exercise price (per share)	0.01
Combined purchase price (per share)	1.81
Stock price underlying warrants (per share)	$ 0.125

Combined purchase price of shares and common warrants.

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Gross proceeds from issuance of common stock and warrants.

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Number of common warrants for each share.

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Share price of shares of common stock underlying warrants.

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Number of consecutive trading days.

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

+ References

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Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Price of a single share of a number of saleable stocks of a company.

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Number of new stock issued during the period.

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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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