Leases - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) Option	Dec. 31, 2018 USD ($) retail_property
Lessee, Lease, Description [Line Items]
Operating lease undiscounted amount	$ 6.6
Finance lease undiscounted amount	$ 4.9
Number of retail stations under capital leases | retail_property		17
Option to renew | Option	1
Operating lease, average remaining lease term		8 years
Rent expense		$ 41.6
Minimum
Lessee, Lease, Description [Line Items]
Renewal term	1 year
Capital lease, renewal term		1 year
Maximum
Lessee, Lease, Description [Line Items]
Renewal term	30 years
Capital lease, renewal term		15 years