Segment, Geographical and Other Revenue Information - Concentration Risk (Details) - Customer Concentration Risk	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenue, Product and Service Benchmark | Customer A
Concentration Risk [Line Items]
Concentration risk	51.00%		29.00%
Revenue, Product and Service Benchmark | Customer B
Concentration Risk [Line Items]
Concentration risk		13.00%	10.00%
Revenue, Product and Service Benchmark | Customer C
Concentration Risk [Line Items]
Concentration risk		23.00%	12.00%	21.00%
Revenue, Product and Service Benchmark | Customer D
Concentration Risk [Line Items]
Concentration risk		14.00%		22.00%
Revenue, Product and Service Benchmark | Customer E
Concentration Risk [Line Items]
Concentration risk		15.00%		13.00%
Revenue, Product and Service Benchmark | Customer F
Concentration Risk [Line Items]
Concentration risk				11.00%
Accounts Receivable | Customer A
Concentration Risk [Line Items]
Concentration risk			34.00%
Accounts Receivable | Customer C
Concentration Risk [Line Items]
Concentration risk			11.00%		32.00%
Accounts Receivable | Customer E
Concentration Risk [Line Items]
Concentration risk			14.00%		13.00%
Accounts Receivable | Customer F
Concentration Risk [Line Items]
Concentration risk					25.00%