Segment Reporting - Schedule of Reportable Segments (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Total revenues		$ 471,786	$ 554,570
Rental income		21,638	21,721
Income from CST Fuel Supply equity interests		3,426	3,805
Operating income (loss)	[1]	7,612	7,424
Fuel Sales to External Customers [Member]
Segment Reporting Information [Line Items]
Total revenues		429,513	509,317
Food and Merchandise Sales [Member]
Segment Reporting Information [Line Items]
Total revenues		20,016	22,586
Other Revenue [Member]
Segment Reporting Information [Line Items]
Total revenues		619	946
Unallocated [Member]
Segment Reporting Information [Line Items]
Total revenues		(75,881)	(98,393)
Operating income (loss)	[1]	(17,284)	(20,088)
Unallocated [Member] | Fuel Sales to External Customers [Member]
Segment Reporting Information [Line Items]
Total revenues		(75,881)	(98,393)
Wholesale [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues		426,049	501,094
Rental income		19,636	19,755
Income from CST Fuel Supply equity interests		3,426	3,805
Operating income (loss)	[1]	24,288	26,163
Wholesale [Member] | Operating Segments [Member] | Fuel Sales to External Customers [Member]
Segment Reporting Information [Line Items]
Total revenues		329,913	382,000
Wholesale [Member] | Operating Segments [Member] | Other Revenue [Member]
Segment Reporting Information [Line Items]
Total revenues		619	946
Wholesale [Member] | Intersegment [Member] | Fuel Sales to External Customers [Member]
Segment Reporting Information [Line Items]
Total revenues		75,881	98,393
Retail [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total revenues		121,618	151,869
Rental income		2,002	1,966
Operating income (loss)	[1]	608	1,349
Retail [Member] | Operating Segments [Member] | Fuel Sales to External Customers [Member]
Segment Reporting Information [Line Items]
Total revenues		99,600	127,317
Retail [Member] | Operating Segments [Member] | Food and Merchandise Sales [Member]
Segment Reporting Information [Line Items]
Total revenues		$ 20,016	$ 22,586

[1] As discussed in Note 1, as a result of the adoption of ASC 842, operating income for the three months ended March 31, 2019 is not comparable to operating income for the three months ended March 31, 2018. Most significantly, payments on our previous failed sale-leaseback obligations were characterized as principal and interest expense in periods prior to 2019. Starting in 2019, these payments are characterized as rent expense and thus reduce operating income. These payments for the three months ended March 31, 2018 amounted to approximately $1.7 million and $0.1 million for the Wholesale and Retail segments, respectively.