XML 88 R51.htm IDEA: XBRL DOCUMENT v3.21.1
Summary of Significant Accounting Policies - Estimated useful lives of assets (Details) - Other equipment
12 Months Ended
Dec. 31, 2020
Bottom of range  
Disclosure of detailed information about property, plant and equipment [line items]  
Useful lives 3 years
Maximum Member  
Disclosure of detailed information about property, plant and equipment [line items]  
Useful lives 6 years