Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Details)

v3.21.1
Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2021
Mar. 31, 2020
Accounting Policies [Abstract]    
Contract cost, amortization period 1 year  
Fuel revenue and fuel costs included fuel taxes $ 222.5 $ 115.1