Contingent Earnout Share Liability (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Jan. 14, 2020	Dec. 31, 2019	Nov. 30, 2019
Tranche I - EBITDA for last 12 months or 20 trading days in consecutive 30 day trading period
Business Acquisition, Contingent Consideration [Line Items]
Maximum EBITDA before stock conversion										$ 132
Maximum stock price of common stock before conversion (in usd per share)										$ 12.00
Tranche II - LTM EBITDA or 20 trading days in consecutive 30 day trading period
Business Acquisition, Contingent Consideration [Line Items]
Maximum EBITDA before stock conversion										$ 152
Maximum stock price of common stock before conversion (in usd per share)										$ 14.00
Tranche III - LTM EBITDA or 20 trading days in consecutive 30 day trading period
Business Acquisition, Contingent Consideration [Line Items]
Maximum EBITDA before stock conversion										$ 172
Maximum stock price of common stock before conversion (in usd per share)										$ 16.00
Class A-2 Common Stock
Business Acquisition, Contingent Consideration [Line Items]
Class A-1 Common Stock reserved for issuance (in shares)										10,000,000
Class A-2 Common Stock | Tranche I - EBITDA for last 12 months or 20 trading days in consecutive 30 day trading period
Business Acquisition, Contingent Consideration [Line Items]
Number of shares converted (in shares)								1,666,666		1,666,666
Class A-2 Common Stock | Tranche II - LTM EBITDA or 20 trading days in consecutive 30 day trading period
Business Acquisition, Contingent Consideration [Line Items]
Number of shares converted (in shares)										1,666,667
Class A-2 Common Stock | Tranche III - LTM EBITDA or 20 trading days in consecutive 30 day trading period
Business Acquisition, Contingent Consideration [Line Items]
Number of shares converted (in shares)								1,666,636		1,666,667
Class A-2 Common Stock | Common Stock
Business Acquisition, Contingent Consideration [Line Items]
Shares issued (in shares)										5,000,000
Class A-1 Common Stock
Business Acquisition, Contingent Consideration [Line Items]
Percentage of ownership requiring exchange (less than)								4.99%
Class A-1 Common Stock | Common Stock
Business Acquisition, Contingent Consideration [Line Items]
Shares issued (in shares)	94,042,341	93,660,753	93,379,508	93,379,508	92,146,013	78,382,405	78,234,106		76,637,470