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%