Description of Business and Basis of Presentation (Details)		1 Months Ended
	Aug. 30, 2013	Mar. 31, 2013 USD ($) shares	Jun. 30, 2020 station store state $ / shares	Jan. 01, 2020 USD ($)	Dec. 31, 2019 $ / shares	Jun. 30, 2013 $ / shares
Product Information [Line Items]
Number Of Stores Sold | store			9
Number of states in which entity operates | state			25
Number of stations			1,485
Common stock shares issued (in shares) | shares		100
Common stock par value (in dollars per share) | $ / shares			$ 0.01		$ 0.01	$ 0.01
Proceeds from issuance of common stock | $		$ 1.00
Percentage of shares of stock distributed (percent)	100.00%
Accounting Standards Update 2016-13
Product Information [Line Items]
Allowance for credit loss | $				$ 1,100,000
Murphy USA
Product Information [Line Items]
Number of stations			1,152
Murphy Express
Product Information [Line Items]
Number of stations			333