Stockholder's Equity (Deficit) - Schedule of Common Stock Reserved for Future Issuance (Details) - shares	Jun. 30, 2021	Jun. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance	5,992,019	5,118,954
Warrants
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance		2,002,550
Montrose 2013 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance	2,047,269	2,050,244
Montrose 2017 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock reserved for future issuance	3,944,750	1,066,160