Fair Value Measurements - Warrant Derivative Liability (Activity in Level 3) (Details)
|12 Months Ended|
Apr. 30, 2018
|Fair Value Disclosures [Abstract]|
|Balance Begnning||$ 52,500|
|Gain on extinguishment of warrant liability||(52,500)|
Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef