Summary of Significant Accounting Policies Concentration of Credit Risk (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Disclosure On Geographic Areas Revenue From External Customers Attributed to France			18.00%
Disclosure on Geographic Areas, Revenue from External Customers Attributed to Entity's Country of Domicile, Percent	10.00%	40.00%	17.00%
Disclosure On Geographic Areas Revenue From External Customers Attributed to Germany	89.00%	53.00%	65.00%