XML 58 R47.htm IDEA: XBRL DOCUMENT v3.21.2
Summary of Significant Accounting Policies - Contract Assets and Contract Liabilities (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Accounting Policies [Abstract]        
Revenue recognized included in contract liabilities $ 0.3 $ 0.2 $ 0.8 $ 0.7