Summary of Significant Accounting Policies Concentration of Credit Risk (Details) |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
Accounting Policies [Abstract] | |||
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Entity's Country of Domicile, Percent | 98.00% | 10.00% | 40.00% |
Disclosure On Geographic Areas Revenue From External Customers Attributed to Germany | 89.00% | 53.00% |