Reportable Segments - Revenue and Total Assets by Geographic Area (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Revenues and total assets by geographic area
% of Revenue	100.00%	100.00%	100.00%	100.00%
Non-United States
Revenues and total assets by geographic area
% of Revenue			3.50%	5.30%
% of total assets			3.80%		4.40%