CST Arkansas Stations S-4/A 18 Oct 13 Registration of securities issued in business combination transactions (amended) Financial data

Document_and_Entity_Informatio

Document and Entity Information Document	6 Months Ended
	Jun. 30, 2013
Document Information
Entity Registrant Name	CST Brands, Inc.
Entity Central Index Key	1562039
Document Type	S-4/A
Document Period End Date	30-Jun-13
Entity Filer Category	Non-accelerated Filer
Amendment Flag	FALSE

Consolidated_and_Combined_Bala

Consolidated and Combined Balance Sheets (USD $)	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
In Millions, unless otherwise specified
Current assets:
Cash	$414	$61	$54	$132	$102	$103
Receivables, net	197	134		172
Inventories	163	168		159
Deferred income taxes	9	13		12
Prepaid expenses and other	14	8		10
Total current assets	797	384		485
Property and equipment, at cost	1,892	1,863		1,678
Accumulated depreciation	618	587		525
Property and equipment, net	1,274	1,276		1,153
Goodwill and intangible assets, net	53	41		47
Deferred income taxes	112	0
Other assets, net	71	8		6
Total assets	2,307	1,709		1,691
Current liabilities:
Current portion of debt and capital lease obligations	29	1		1
Accounts payable	83	95		84
Accounts payable to Valero	342	0
Accrued expenses	44	40		41
Taxes other than income taxes	23	92		86
Income taxes payable	9	0
Total current liabilities	530	228		212
Debt and capital lease obligations, less current portion	1,025	4		5
Deferred income taxes	89	123		124
Other long-term liabilities	112	107		101
Commitments and contingencies
Stockholders’ equity / net investment:
Common stock (250,000,000 shares authorized at $0.01 par value and 75,397,241 issued and outstanding at June 30, 2013)	1	0
Additional paid-in capital (APIC)	395	0
Net parent investment	0	1,082		1,094
Retained earnings	20	0
Accumulated other comprehensive income (AOCI)	135	165		155
Total stockholders' equity	551	1,247		1,249	1,193	1,197
Total net investment		1,247		1,249
Total liabilities and stockholders’ equity / net investment	$2,307	$1,709		$1,691

Consolidated_and_Combined_Bala1

Consolidated and Combined Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2013	Dec. 31, 2012
In Millions, except Share data, unless otherwise specified
Allowance for doubtful accounts receivable, current	$1	$2
Common stock, shares authorized	250,000,000
Common stock, par or stated value per share	$0.01
Common stock shares issued	75,397,241
Common stock shares outstanding	75,397,241

Consolidated_and_Combined_Stat

Consolidated and Combined Statements of Income (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating revenues (a)	$3,211	$3,345	$6,399	$6,557	$13,135	$12,863	$10,371
Costs and expenses:
Cost of sales	2,919	2,977	5,874	5,973	12,000	11,735	9,310
Operating expenses	161	161	320	316	644	636	605
General and administrative expenses	20	14	35	29	61	59	57
Depreciation, amortization and accretion expense	30	29	60	56	115	113	105
Asset impairment losses					0	3	5
Total costs and expenses	3,130	3,181	6,289	6,374	12,820	12,546	10,082
Operating income	81	164	110	183	315	317	289
Other income, net	1	0	2	0	1	1	2
Interest expense	7	0	7	0	1	1	1
Income before income tax expense	75	164	105	183	315	317	290
Income tax expense	32	56	41	61	105	103	97
Net income	43	108	64	122	210	214	193
Earnings per common share
Basic earnings per common share	$0.57	$1.43	$0.84	$1.62
Weighted-average common shares outstanding (in thousands)	75,397	75,397	75,397	75,397
Earnings per common share – assuming dilution
Diluted earnings per common share	$0.57	$1.43	$0.84	$1.62
Weighted-average common shares outstanding – assuming dilution (in thousands)	75,407	75,397	75,402	75,397
Supplemental information:
(a) Includes excise taxes of:	$336	$501	$811	$979	$1,987	$1,947	$1,853

Consoldiated_and_Combined_Stat

Consoldiated and Combined Statements of Comprehensive Income Statement (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$43	$64	$23	$108	$15	$48	$55	$80	$31	$64	$122	$210	$214	$193
Other comprehensive income (loss):
Foreign currency translation adjustment	-20			-8						-30	1	10	-7	24
Other comprehensive income (loss) before income taxes	-20			-8						-30	1	10	-7	24
Income taxes related to items of other comprehensive income	0			0						0	0	0	0	0
Other comprehensive income (loss)	-20			-8						-30	1	10	-7	24
Comprehensive income	$23			$100						$34	$123	$220	$207	$217

Consolidated_and_Combined_Stat1

Consolidated and Combined Statements of Cash Flows (USD $)	6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net income	$64	$122	$210	$214	$193
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	2	1	2	3	2
Depreciation, amortization and accretion expense	60	56	115	113	105
Asset impairment losses			0	3	5
Non-cash interest expense			0	1	0
Deferred income tax expense	8	-4	-1	12	6
Changes in current assets and current liabilities	217	22	42	-40	12
Other operating activities, net	0	3	-2	5	2
Net cash provided by operating activities	351	200	364	308	323
Cash flows from investing activities:
Capital expenditures	-90	-46	-156	-130	-105
Acquisitions	-4	-61	-61	0	0
Proceeds from dispositions of property and equipment	0	2	2	5	3
Other investing activities, net	-2	0	0	-2	-2
Net cash used in investing activities	-96	-105	-215	-127	-104
Cash flows from financing activities:
Proceeds from issuance of long-term debt	500	0
Debt issuance and credit facility origination costs	-18	0
Payments of capital lease obligations	-1	0	-1	-1	-1
Net transfers to Valero	-378	-172	-219	-150	-220
Net cash provided by (used in) financing activities	103	-172	-220	-151	-221
Effect of foreign exchange rate changes on cash	-5	-1	0	0	1
Net increase (decrease) in cash	353	-78	-71	30	-1
Cash at beginning of period	61	132	132	102	103
Cash at end of period	$414	$54	$61	$132	$102

Consolidated_and_Combined_Stat2

Consolidated and Combined Statement of Stockholders' Equity Statement (USD $)	Total	Common Stock	Common Stock Par Value	Additional Paid-in Capital	Net Parent Investment	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
In Millions	USD ($)		USD ($)	USD ($)	USD ($)	USD ($)	USD ($)
Stockholders' equity at Dec. 31, 2009	$1,197				$1,059		$138
Net income	193				193		0
Net transfers to Valero	-221				-221		0
Other comprehensive income (loss)	24				0		24
Other comprehensive loss	24
Stockholders' equity at Dec. 31, 2010	1,193				1,031		162
Net income	214				214		0
Net transfers to Valero	-151				-151		0
Other comprehensive income (loss)	-7				0		-7
Other comprehensive loss	-7
Stockholders' equity at Dec. 31, 2011	1,249				1,094		155
Net income	210				210		0
Net transfers to Valero	-222				-222		0
Other comprehensive income (loss)	10				0		10
Other comprehensive loss	10
Shares, outstanding		0
Stockholders' equity at Dec. 31, 2012	1,247		0	0	1,082	0	165
Net income	64				44	20
Net transfers to Valero	-731				-731
Other comprehensive income (loss)	-30						-30
Issuance of stock at the separation and distribution, shares		75
Issuance of stock at the separation and distribution			1	-1
Reclassification of net parent investment to APIC				395	-395
Stock-based compensation expense	1			1
Other comprehensive loss	-30						-30
Shares, outstanding		75
Stockholders' equity at Jun. 30, 2013	$551		$1	$395	$0	$20	$135

The_Separation_and_the_Distrib

The Separation and the Distribution, Basis of Presentation Description of Business and Summary of Significant Accounting Policies	6 Months Ended		12 Months Ended
	Jun. 30, 2013		Dec. 31, 2012
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Significant Accounting Policies	THE SEPARATION AND DISTRIBUTION, BASIS OF PRESENTATION, CONCENTRATION RISK AND INTERIM FINANCIAL INFORMATION		THE SEPARATION AND THE DISTRIBITION, BASIS OF PRESENTATION, DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	The Separation and Distribution		The Separation and the Distribution
	On April 4, 2013, the Valero Energy Corporation (“Valero” or “Parent”) Board of Directors approved the separation and distribution (the “separation and distribution”) of its retail business resulting in a separate, publicly traded company named CST Brands, Inc. (“CST”). In accordance with a separation and distribution agreement, the two companies were separated by Valero’s distributing to its stockholders 80% of the common stock of CST on May 1, 2013 (the “Distribution Date”). Each Valero stockholder received one share of CST common stock for every nine shares of Valero common stock held at the close of business on the record date of April 19, 2013 (the “Record Date”). Fractional shares of CST common stock were not distributed and any fractional shares of CST common stock otherwise issuable to a Valero stockholder were sold in the open market on such stockholder’s behalf, and such stockholder received a cash payment with respect to that fractional share. The remaining 20% of the common stock of CST was retained by Valero. In conjunction with the separation and distribution, Valero received a private letter ruling from the Internal Revenue Service to the effect that the distribution will not result in any taxable income, gain or loss to Valero, except for taxable income or gain arising as a result of certain intercompany transactions, and no gain or loss will be recognized by (and no amount will be included in the income of) United States (“U.S.”) holders of Valero common stock upon their receipt of shares of CST common stock in the distribution, except with respect to cash received in lieu of fractional shares. However, the transfer of assets and liabilities associated with Valero’s retail business in Canada is taxable for Canadian income tax purposes.		On July 31, 2012, Valero Energy Corporation (“Valero” or “Parent”) announced approval by its Board of Directors to pursue the separation of its retail business into a stand-alone, publicly traded corporation, CST Brands, Inc. (“CST”). On May 1, 2013 Valero distributed to its stockholders 80% of the shares of CST common stock as of the record date for the distribution and retained the remaining 20%. CST was incorporated in Delaware as a wholly owned subsidiary of Valero in November 2012.
	In connection with the separation and distribution, CST incurred an aggregate of $1.05 billion in new debt, consisting of: (i) $550 million aggregate principal amount of senior unsecured bonds (the “notes”); and (ii) $800 million in senior secured credit facilities, comprised of a $500 million term loan facility (the “term loan”) and a $300 million revolving credit facility (the “revolving credit facility”). We have not borrowed under the revolving credit facility as of the date of this filing; however approximately $3 million of letters of credit have been issued under this facility. For more information on the indebtedness, see Note 7 to these condensed notes to consolidated and combined financial statements.		Basis of Presentation
	We transferred the cash proceeds of the term loan to Valero and issued the notes to Valero in connection with the separation of the assets (including the equity interests of certain Valero subsidiaries) and liabilities of Valero’s retail business from Valero and the transfer of those assets (including the equity interests of certain Valero subsidiaries) and liabilities to us. Valero transferred our notes to a third-party lender to satisfy certain of Valero’s then-outstanding debt obligations. As a result of these financing transactions, we incurred total indebtedness of $1.05 billion for which we did not retain any cash following the separation and distribution.		As previously noted, CST was incorporated in November 2012 and, in connection with its incorporation, CST issued 1,000 shares of common stock, par value $0.01 per share, to Valero for $10. CST was formed solely in contemplation of the separation and distribution, had not commenced operations and had no material assets, liabilities or commitments prior to the separation and distribution.
	As a result of the separation and distribution, the tax basis of certain of our Retail–U.S. assets related to certain historical intercompany transactions between Valero and us were stepped-up, but the historical book basis of these assets was not stepped-up because the distribution represents a transaction with Valero’s stockholders. Therefore, we realized an $18 million adjustment to a portion of our U.S. deferred income tax liabilities.		These combined financial statements were prepared in connection with the expected separation and distribution and are derived from the consolidated financial statements and accounting records of Valero. These statements reflect the combined historical financial position, results of operations and cash flows of CST and Valero’s retail business in the United States (“U.S.”) and Canada that were owned by direct and indirect wholly owned subsidiaries of Valero, including an allocable portion of Valero’s corporate costs. The legal transfer of the assets (including the equity interests of certain Valero subsidiaries), liabilities and operations of Valero’s retail business into CST occurred on May 1, 2013. However, for ease of reference, these combined financial statements are referred to as those of CST. Unless otherwise stated or the context otherwise indicates, all references in these combined financial statements to “us,” “our,” or “we” mean the retail business of Valero, which is referred to as CST.
	The separation and distribution was a taxable event in Canada, and as a result, the tax basis of certain assets and liabilities of our Retail–Canada segment were stepped up to their fair values. The historical book basis of those assets and liabilities, however, were not stepped-up because they were wholly owned by Valero and were transferred within the Valero consolidated group. As a result, we recognized a deferred tax asset of $115 million from the step-up in the tax basis of those assets and liabilities.		The financial statements are presented as if Valero’s U.S. and Canadian retail operations had been combined for all years presented. Neither operation, however, carried out transactions with the other during the years presented; therefore, there were no intercompany transactions or accounts to be eliminated in connection with the combination of these operations. The assets and liabilities in the combined balance sheets have been reflected on a historical cost basis, as immediately prior to the separation and the distribution, and all of the assets and liabilities presented were wholly owned by Valero and were transferred within the Valero consolidated group. The combined statements of income also include expense allocations for certain corporate functions historically performed by Valero and not allocated to its operating segments, including allocations of general corporate expenses related to executive oversight, accounting, treasury, tax, legal, procurement and information technology. These allocations are based primarily on specific identification of time and/or activities associated with CST, employee headcount or capital expenditures. Our management believes the assumptions underlying the combined financial statements, including the assumptions regarding allocating general corporate expenses from Valero, are reasonable. Nevertheless, the combined financial statements may not include all of the actual expenses that would have been incurred had we been a stand-alone company during the years presented and may not reflect our combined financial position, results of operations and cash flows had we been a stand-alone company during the periods presented. Actual costs that would have been incurred if we had been a stand-alone company would depend on multiple factors, including organizational structure and strategic decisions made in various areas, including information technology and infrastructure.
	Also as a result of the separation and distribution, we recorded $7 million of deferred tax expense related to the loss of certain state tax credits that were no longer eligible for use in our consolidated tax return as a result of the separation and distribution.		Valero uses a centralized approach to cash management and the financing of its operations. We transfered cash to Valero daily and Valero funded our operating and investing activities as needed. Accordingly, cash held by Valero at the corporate level was not allocated to us for any of the years presented. Cash presented on our combined balance sheets represents cash on hand at our convenience stores, cash that had not yet been transferred to Valero and cash held by us in automated teller machines (“ATMs”). We reflected transfers of cash to and from Valero’s cash management system as a component of net parent investment on our combined balance sheets, and these net transfers of cash are reflected as a financing activity in our combined statements of cash flows. We also have not included any interest income on the net cash transfers to Valero.
	CST was not responsible for any tax payments related to the separation and distribution in the U.S. and Canada.		Description of Business
	A registration statement on Form 10, as amended through the time of its effectiveness, describing the separation and the distribution was filed by CST with the U.S. Securities and Exchange Commission (“SEC”) and was declared effective on April 11, 2013 (the “Form 10”). On May 2, 2013, CST stock began trading on the New York Stock Exchange under the “CST” stock symbol.		We are one of the largest independent retailers of motor fuel and convenience merchandise items in the U.S. and eastern Canada. Our operations include (i) the sale of motor fuel at convenience stores, filling stations and cardlocks (which is an unattended self-service filling station that provides motor fuel to fleet customers, such as trucking and other commercial customers), (ii) the sale of convenience merchandise items and services in convenience stores and (iii) the sale of heating oil to residential customers and the sale of heating oil and motor fuel to small commercial customers. We generally refer to a convenience store, filling station or cardlock as a “retail site.”
	Basis of Presentation		Significant Accounting Policies
	CST was incorporated in November 2012 and, in connection with its incorporation, CST issued 1,000 shares of common stock, par value $0.01 per share, to Valero for $10. CST was formed solely in contemplation of the separation and distribution and, prior to May 1, 2013, had not commenced operations and had no material assets, liabilities or commitments.		Principles of Combination
	Prior to the separation and distribution, these financial statements reflect the combined historical financial position, results of operations and cash flows of Valero’s retail business in the U.S. and Canada that were owned by direct and indirect wholly-owned subsidiaries of Valero, including an allocable portion of Valero’s corporate costs. The legal transfer of the assets (including the equity interests of certain Valero subsidiaries), liabilities and operations of Valero’s retail business into CST occurred on May 1, 2013. However, for ease of reference, these consolidated and combined financial statements are referred to as those of CST. Unless otherwise stated or the context otherwise indicates, all references in these consolidated and combined financial statements to “us,” “our,” or “we” mean CST.		These combined financial statements were prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and include the accounts of direct and indirect wholly owned subsidiaries of Valero that hold the assets and liabilities and reflect the operations of Valero’s retail business in the U.S. and Canada. These subsidiaries, however, did not carry out any transactions with each other during the years presented; therefore, there were no transactions or accounts to be eliminated in connection with the combination.
	Neither of our segments carried out transactions with the other during the periods presented; therefore, there were no intercompany transactions or accounts to be eliminated in connection with the consolidation or combination of these operations.		Net Parent Investment
	The unaudited combined financial statements are presented as if Valero’s retail businesses in the U.S. and Canada had been combined for all periods prior to the separation and distribution. The assets and liabilities in the combined balance sheets have been reflected on a historical cost basis, as immediately prior to the separation and distribution. All of the assets and liabilities presented were wholly owned by Valero and were transferred within the Valero consolidated group. The combined statements of income prior to the separation and distribution also include expense allocations for certain corporate functions historically performed by Valero and not allocated to its operating segments, including allocations of general corporate expenses related to executive oversight, accounting, treasury, tax, legal, procurement, human resources and information technology (“IT”). These allocations were based primarily on specific identification of time and/or activities associated with CST’s operations, employee headcount or capital expenditures. We believe the assumptions underlying the combined financial statements, including the assumptions regarding allocating general corporate expenses from Valero, are reasonable. Subsequent to the separation and distribution, Valero continues to perform certain of these corporate functions on our behalf, for which we are charged a fee, in accordance with the Transition Services Agreements. Nevertheless, the combined financial statements may not include all of the actual expenses that would have been incurred had we operated as a stand-alone company during the combined periods presented and may not reflect our combined financial position, results of operations and cash flows had we operated as a stand-alone company during the combined periods presented. Actual costs that would have been incurred if we had operated as a stand-alone company during the combined periods presented would depend on multiple factors, including organizational structure and strategic decisions made in various areas, including IT and related infrastructure.		The net parent investment represents Valero’s historical investment in CST, CST’s accumulated net earnings after taxes and the net effect of transactions with, and allocations from, Valero.
	Prior to the separation and distribution, we transferred cash to Valero daily and Valero funded our operating and investing activities as needed. Accordingly, cash held by Valero at the corporate level was not allocated to us. Cash presented on our combined balance sheet prior to the separation and distribution represented cash on hand at our convenience stores, cash that had not yet been transferred to Valero and cash held by us in automated teller machines (“ATMs”) in our Retail–Canada segment. We reflected transfers of cash to and from Valero’s cash management system as a component of net parent investment on our combined balance sheet, and these net transfers of cash were reflected as a financing activity in our combined statement of cash flows. We did not include any interest income on the net cash transfers to Valero.		Use of Estimates
	The consolidated financial statements reflect our financial results for all periods subsequent to the separation and distribution while the combined financial statements reflect our financial results for all periods prior to the separation and distribution. Accordingly:		The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported in the combined financial statements and accompanying notes. Actual results could differ from those estimates. On an ongoing basis, we review our estimates based on currently available information. Changes in facts and circumstances may result in revised estimates.
			Receivables
	•	Our consolidated and combined statement of income and comprehensive income for the three months ended June 30, 2013, consists of the consolidated results of CST for the two months ended June 30, 2013 and the combined results of Valero’s retail business for the one month ended April 30, 2013. Our consolidated and combined statement of income and comprehensive income for the six months ended June 30, 2013, consists of the consolidated results of CST for the two months ended June 30, 2013 and of the combined results of Valero’s retail business for the four months ended April 30, 2013. Our combined statements of income and comprehensive income for the three and six months ended June 30, 2012 consist entirely of the combined results of Valero’s retail business.	Receivables represent amounts due from credit card companies and from our heating oil customers (“trade receivables”). Trade receivables are carried at original invoice amount. Other receivables consist primarily of amounts due from financial institutions as reimbursement for cash distributed from ATM machines that were funded by us and amounts due from vendors related to vendor rebates (see “Vendor Allowances and Rebates” for our policy regarding the accounting for vendor rebates). We maintain an allowance for doubtful accounts, which is adjusted based on management’s assessment of our customers’ historical collection experience, known credit risks and industry and economic conditions.
			Inventories
	•	Our consolidated balance sheet at June 30, 2013, consists of the consolidated balances of CST, while our combined balance sheet at December 31, 2012 consists of the combined balances of Valero’s retail business.	Inventories are carried at the lower of cost or market. The cost of supplies and convenience store merchandise is determined principally under the weighted-average cost method. The cost of motor fuel inventories is determined under the last-in, first-out (“LIFO”) method using the dollar-value LIFO method, with any increments valued based on purchase prices at the end of the year.
			Property and Equipment
	•	Our consolidated and combined statement of cash flows for the six months ended June 30, 2013, consists of the consolidated results of CST for the two months ended June 30, 2013 and the combined results of Valero’s retail business for the four months ended April 30, 2013. Our combined statement of cash flows for the six months ended June 30, 2012 consists entirely of the combined results of Valero’s retail business.	The cost of property and equipment purchased or constructed, including betterments of property assets, is capitalized. However, the cost of repairs and normal maintenance of property and equipment is expensed as incurred. Betterments of property and equipment are those which extend the useful lives of the property and equipment or improve the safety of our operations. Betterments also include additions to and enlargements of our retail sites. The cost of property and equipment constructed includes certain overhead costs allocable to the construction activities.
			When property and equipment are retired or replaced, the cost and related accumulated depreciation are eliminated, with any gain or loss reflected in depreciation, amortization and accretion expense, unless such amounts are reported separately due to materiality.
	•	Our consolidated and combined statement of changes in equity for the six months ended June 30, 2013 consists of both the combined activity of Valero’s retail business prior to April 30, 2013 and the consolidated activity of CST subsequent to the separation and distribution.	Depreciation of property and equipment is recorded on a straight-line basis over the estimated useful lives of the related assets. Leasehold improvements and assets acquired under capital leases are amortized using the straight-line method over the shorter of the lease term or the estimated useful life of the related asset.
	Concentration Risk		Impairment of Assets
	Valero supplied substantially all of the motor fuel purchased by us for resale during all periods presented.		Long-lived assets, which include property and equipment and finite-lived intangible assets, are tested for recoverability whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. A long-lived asset is not recoverable if its carrying amount exceeds the sum of the undiscounted cash flows expected to result from its use and eventual disposition. If a long-lived asset is not recoverable, an impairment loss is recognized for the amount by which the carrying amount of the long-lived asset exceeds its fair value, with fair value determined based on discounted estimated net cash flows or other appropriate methods. See Note 3 for our impairment analysis of our long-lived assets.
	We entered into a Branded Distributor Marketing Agreement, a Petroleum Product Sale Agreement and a Master Agreement with Valero in connection with the separation and distribution for the supply of motor fuel to our Retail–U.S. operations, which we refer to as the “U.S. Fuel Supply Agreements.” In addition, we entered into a separate Petroleum Product Supply Agreement with Valero for the supply of motor fuel to our Retail–Canada segment. Under the U.S. Fuel Supply Agreements and the Product Supply Agreement in Canada, we will continue to purchase motor fuel from Valero. The U.S. Fuel Supply Agreements and Petroleum Product Supply Agreement in Canada contain minimum annual purchase obligations. The minimum purchase obligation provisions of these agreements require us to purchase minimum annual volumes of motor fuel at market-based prices. In the event that we do not purchase the minimum volumes, the agreements include a charge for the difference between the total minimum volume commitment to be purchased over the terms of the agreements and the volumes actually purchased by us. This amount will decline over time as we purchase motor fuel from Valero.		Environmental Matters
	No customers are individually material to our operations.		Liabilities for future remediation costs are recorded when environmental assessments from governmental regulatory agencies and/or remedial efforts are probable and the costs can be reasonably estimated. Other than for assessments, the timing and magnitude of these accruals generally are based on the completion of investigations or other studies or a commitment to a formal plan of action. Environmental liabilities are based on best estimates of probable undiscounted future costs using currently available technology and applying current regulations, as well as our own internal environmental policies, without establishing a range of loss for these liabilities. Environmental liabilities are difficult to assess and estimate due to uncertainties related to the magnitude of possible remediation, the timing of such remediation and the determination of our obligation in proportion to other parties. Such estimates are subject to change due to many factors, including the identification of new sites requiring remediation, changes in environmental laws and regulations and their interpretation, additional information related to the extent and nature of remediation efforts and potential improvements in remediation technologies. Amounts recorded for environmental liabilities have not been reduced by possible recoveries from third parties.
	Interim Financial Information
	These unaudited financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities Exchange Act of 1934. Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments considered necessary for a fair presentation have been included. All such adjustments are of a normal recurring nature unless disclosed otherwise. Management believes that the disclosures made are adequate to make the information presented not misleading. The financial statements contained herein should be read in conjunction with the combined financial statements and notes thereto included in the Form 10. Financial information for the three and six months ended June 30, 2013 and 2012 included in these condensed notes to consolidated and combined financial statements is derived from our unaudited financial statements. Operating results for the three and six months ended June 30, 2013 are not necessarily indicative of the results that may be expected for the year ending December 31, 2013.		Asset Retirement Obligations
	The balance sheet as of December 31, 2012 has been derived from our audited financial statements as of that date. For further information, refer to our financial statements and notes thereto included in our Form 10.		We record a liability, which is referred to as an asset retirement obligation, at fair value for the estimated cost to remove underground storage tanks (“USTs”) for motor fuel at owned and leased retail sites at the time we incur that liability, which is generally when the UST is installed. We record a discounted liability for the fair value of an asset retirement obligation with a corresponding increase to the carrying value of the related long-lived asset. We depreciate the amount added to property and equipment and recognize accretion expense in connection with the discounted liability over the remaining life of the UST. Accretion expense is reflected in depreciation, amortization and accretion expense. We base our estimates of the anticipated future costs for removal of a UST on our prior experience with removal. Removal costs include the cost to remove and destroy the USTs, soil remediation costs resulting from the spillage of small quantities of motor fuel in the normal operations of our business and other miscellaneous costs. We review our assumptions for computing the estimated liability for the removal of USTs on an annual basis. Any change in estimated cash flows is reflected as an adjustment to the liability and the associated asset.
			Foreign Currency Translation
			The functional currency of our Canadian operations is the Canadian dollar. Balance sheet accounts are translated into U.S. dollars using exchange rates in effect as of the balance sheet date. Revenue and expense accounts are translated using the weighted-average exchange rates during the year presented. Foreign currency translation adjustments are recorded as a component of accumulated other comprehensive income.
			Revenue Recognition
			Revenues are recorded upon delivery of the products to our customers, which is the point at which title to the products is transferred, and when payment has either been received or collection is reasonably assured.
			We present motor fuel excise taxes on sales on a gross basis with supplemental information regarding the amount of such taxes included in revenues provided in a footnote on the face of the statements of income.
			Shipping and Handling Costs
			Costs incurred for the shipping and handling of motor fuel and convenience store merchandise are included in inventories, and therefore, reflected in cost of sales when the related item is sold.
			Income Taxes
			Income taxes are accounted for under the asset and liability method, as if we were a separate taxpayer rather than a member of Valero’s consolidated income tax return. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred amounts are measured using enacted tax rates expected to apply to taxable income in the year those temporary differences are expected to be recovered or settled.
			We classify any interest expense and penalties related to the underpayment of income taxes in income tax expense.
			Vendor Allowances and Rebates
			We receive payments for vendor allowances and volume rebates from various suppliers of convenience store merchandise. Our accounting practices are as follows:
			•	Vendor allowances for price markdowns are credited to cost of sales during the period the related markdown is taken.
			•	Volume rebates of merchandise are recorded as reductions to cost of sales when the merchandise qualifying for the rebate is sold.
			•	Slotting and stocking allowances received from a vendor are recorded as a reduction to cost of sales over the period covered by the agreement.
			The aggregate amounts recorded as a reduction to cost of sales for vendor allowances and rebates for the years ended December 31, 2012, 2011 and 2010 were $70 million, $62 million and $63 million, respectively. The recording of vendor allowances and rebates does not require us to make any significant estimates.
			Concentration Risk
			Valero supplied substantially all of the motor fuel purchased by us for resale during all years presented. No customers are individually material to our operations.

Acquisitions

Acquisitions	6 Months Ended			12 Months Ended
	Jun. 30, 2013			Dec. 31, 2012
Business Combinations [Abstract]
Business Combination Disclosure	ACQUISITIONS			ACQUISITION
	In July 2012, we completed the acquisition of The Crackerbox, LLC (“Crackerbox”) for total cash consideration of $61 million. No contingent assets or liabilities were acquired or assumed. In the first quarter of 2013, an independent appraisal of the assets acquired through the acquisition of Crackerbox was completed. The purchase price of Crackerbox was allocated based on the fair values of the assets acquired at the date of acquisition resulting from this appraisal. The primary changes to the preliminary purchase price allocation disclosed in the Form 10 consisted of an $18 million adjustment to goodwill resulting from a change in the estimated fair value of property and equipment. The purchase price allocation of the acquisition of Crackerbox was determined based on the acquisition-date fair values of the assets acquired and is as follows (in millions):			In June 2012, we signed an agreement with The Crackerbox, LLC to buy 29 convenience stores located in the Little Rock and Hot Springs, Arkansas areas. In July 2012, we completed the acquisition of these sites, including motor fuel inventories, for total cash consideration of $61 million, and no contingent assets or liabilities were acquired or assumed.
				The assets acquired were recognized at their acquisition-date estimated fair values as follows (in millions):
	Inventories	$	3
				Inventories	$	3
	Property and equipment	38
				Property and equipment	56
	Other assets	2
				Other assets	2
	Goodwill	18
				Total consideration	$	61
	Total consideration	$	61
				In the first quarter of 2013, we received an independent appraisal of the fair value of the assets acquired, which resulted in an $18 million adjustment to goodwill from a change in the estimated fair value of property and equipment.
	The adjustment to property and equipment discussed above did not result in a material adjustment to depreciation expense.			We have not presented pro forma results of operations for the year ended December 31, 2012, or actual results of operations from the acquisition date through December 31, 2012, because this acquisition was not material to our results of operations. The combined statements of income for the year ended December 31, 2012 include the results of the acquisition since the acquisition date.
	We have not presented pro forma results of operations for the three and six months ended June 30, 2012 because this acquisition was not material to our results of operations.
	During 2013, we acquired one new company operated site and converted three dealer/agent sites to company operated sites in our Retail–Canada segment for $4 million.

Earnings_per_Common_Share

Earnings per Common Share	6 Months Ended
	Jun. 30, 2013
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER COMMON SHARE
	Basic earnings per common share is computed by dividing the net income available to common stockholders by the weighted average of common shares outstanding during the period. Diluted earnings per common share adjusts basic earnings per common share for the effects of stock options and restricted stock in the periods in which such effect is dilutive.
	On May 1, 2013, 75,397,241 shares of our common stock were distributed to Valero’s stockholders and Valero in conjunction with the separation and distribution. For comparative purposes, and to provide a more meaningful calculation of earnings per share, we have assumed this amount to be outstanding as of the beginning of each period prior to the separation and distribution presented in the calculation of weighted-average shares outstanding.
	The following table provides a reconciliation of basic and diluted earnings per common share computations for the three and six months ended June 30, 2013 and 2012 (in millions, except per share amounts):
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2013		2012		2013		2012
	Earnings per common share:
	Net income attributable to stockholders	$	43	$	108	$	64	$	122
	Weighted-average common shares outstanding (in thousands)	75,397		75,397		75,397		75,397
	Total earnings per share	$	0.57	$	1.43	$	0.84	$	1.62
	Earnings per common share - assuming dilution:
	Net income attributable to stockholders	$	43	$	108	$	64	$	122
	Weighted-average common shares outstanding (in thousands)	75,397		75,397		75,397		75,397
	Common equivalent shares:
	Restricted stock (in thousands)	10		—		5		—
	Weighted-average common shares outstanding - assuming dilution (in thousands)	75,407		75,397		75,402		75,397
	Earnings per common shares - assuming dilution	$	0.57	$	1.43	$	0.84	$	1.62
	Excluded from the calculation of shares used in the diluted earnings per share calculation for the three months and six months ended June 30, 2013 are 131,622 and 66,174 of weighted-average anti-dilutive options, respectively. Excluded from the calculation of shares used in the diluted earnings per share calculation for the three months and six months ended June 30, 2013 are 106,760 and 53,676 of weighted-average anti-dilutive restricted shares, respectively.
	No stock-based awards of CST were issued in exchange for either vested or non-vested Valero stock-based awards held by our employees prior to the separation and distribution. Therefore, there are no stock-based awards included in the calculation of shares used in the diluted earnings per share prior to the separation and distribution.

Impairment

Impairment	12 Months Ended
	Dec. 31, 2012
impairment of assets [Abstract]
Asset Impairment Charges	IMPAIRMENT
	Our retail sites are the lowest level for which identifiable cash flows are largely independent of the cash flows of other groups of long-lived assets. Cash flows from each retail site vary from year to year and as a result, we identified and recorded asset impairment losses in 2011 and 2010 as changes in market demographics, traffic patterns, competition and other factors impacted the overall operations of certain of our individual retail sites.
	For each retail site where events or changes in circumstances indicated that the carrying amount of the assets might not be recoverable, we compared the retail site’s carrying amount to its estimated future undiscounted cash flows to determine recoverability. If the sum of the estimated undiscounted cash flows did not exceed the carrying value, we then estimated the fair value of these retail sites to measure the impairment. To estimate the fair value of our retail sites, we used an income approach reflecting internally developed cash flows that included, among other things, our expectations of future cash flows based on sales volume, gross margins and operating expenses.
	As a result of our impairment evaluation process, we concluded that some retail sites were impaired. The aggregate carrying values, estimated fair values and asset impairment losses for each segment were as follows (in millions):
		Year Ended December 31,
		2011		2010
	Retail–U.S.:
	Carrying values	$	3	$	3
	Less: Estimated fair values	1		1
	Asset impairment loss	$	2	$	2
	Retail–Canada:
	Carrying values	$	1	$	4
	Less: Estimated fair values	—		1
	Asset impairment loss	$	1	$	3

Receivables

Receivables	12 Months Ended
	Dec. 31, 2012
Receivables [Abstract]
Receivables Disclosure	RECEIVABLES
	Receivables consisted of the following (in millions):
		December 31,
		2012			2011
	Trade receivables	$	115		$	147
	Other	21			27
		136			174
	Allowance for doubtful accounts	(2		)	(2		)
	Receivables, net	$	134		$	172
	Changes in the allowance for doubtful accounts consisted of the following (in millions):
		Year Ended December 31,
		2012			2011			2010
	Balance as of beginning of year	$	2		$	2		$	2
	Increase in allowance charged to expense	—			1			1
	Accounts charged against the allowance, net of recoveries	—			(1		)	(1		)
	Balance as of end of year	$	2		$	2		$	2

Inventories

Inventories	6 Months Ended					12 Months Ended
	Jun. 30, 2013					Dec. 31, 2012
Inventory Disclosure [Abstract]
Inventories Disclosure	INVENTORIES					INVENTORIES
	Inventories consisted of the following (in millions):					Inventories consisted of the following (in millions):
		June 30,		December 31,			December 31,
		2013		2012			2012		2011
	Convenience store merchandise	$	110	$	111	Convenience store merchandise	$	111	$	104
	Motor fuel (at LIFO)	51		56		Motor fuel (at LIFO)	56		54
	Supplies	2		1		Supplies	1		1
	Inventories	$	163	$	168	Inventories	$	168	$	159
	As of June 30, 2013 and December 31, 2012, the replacement cost (market value) of motor fuel inventories exceeded their LIFO carrying amounts by approximately $55 million and $56 million, respectively.					As of December 31, 2012 and 2011, the replacement cost (market value) of motor fuel inventories exceeded their LIFO carrying amounts by approximately $56 million and $56 million, respectively.

Property_and_Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Property and Equipment Disclosure	PROPERTY AND EQUIPMENT
	Major classes of property and equipment consisted of the following (in millions):
		December 31,
		2012			2011
	Land	$	387		$	339
	Retail site buildings	476			406
	Equipment	560			535
	Leasehold improvements	276			254
	Other	135			130
	Construction in progress	29			14
	Property and equipment, at cost	1,863			1,678
	Accumulated depreciation	(587		)	(525		)
	Property and equipment, net	$	1,276		$	1,153
	Depreciation expense for the years ended December 31, 2012, 2011 and 2010 was $103 million, $101 million and $94 million, respectively.
	We had land and certain retail sites under capital leases totaling $9 million and $9 million as of December 31, 2012 and 2011, respectively. Accumulated amortization on assets under capital leases was $5 million and $4 million as of December 31, 2012 and 2011, respectively. See Note 9 for future minimum rentals on capital lease obligations.

Accrued_Expenses_and_Other_Lon

Accrued Expenses and Other Long-term Liabilities	12 Months Ended
	Dec. 31, 2012
Payables and Accruals [Abstract]
Accounts Payable and Accrued Liabilities Disclosure	ACCRUED EXPENSES AND OTHER LONG-TERM LIABILITIES
	Accrued expenses and other long-term liabilities consisted of the following (in millions):
		Accrued Expenses						Other Long-Term
								Liabilities
		December 31,						December 31,
		2012			2011			2012			2011
	Wage and other employee-related liabilities	$	22		$	19		$	—		$	—
	Environmental liabilities	2			2			3			2
	Self-insurance accruals (see Note 9)	6			6			11			12
	Asset retirement obligations	2			2			77			74
	Other	8			12			16			13
	Accrued expenses and other long-term liabilities	$	40		$	41		$	107		$	101
	Environmental Liabilities
	During the year ended December 31, 2012, we added approximately $3 million to our environmental liabilities and settled approximately $2 million of our environmental liabilities. During the two-year period ended December 31, 2011, changes in our environmental liabilities were insignificant, with additions, reductions and settlement activity, each being less than $2 million during each year.
	Asset Retirement Obligations
	We have asset retirement obligations for the removal of USTs at owned and leased retail sites. There is no legal obligation to remove USTs while they remain in service. However, environmental laws in the U.S. and Canada require that USTs be removed within one to two years after the USTs are no longer in service, depending on the jurisdiction in which the USTs are located. We have estimated that USTs at our owned retail sites will remain in service approximately 20 years and that we will have an obligation to remove those USTs at that time. For our leased retail sites, our lease agreements generally require that we remove certain improvements, primarily USTs and signage, upon termination of the lease. There are no assets that are legally restricted for purposes of settling our asset retirement obligations.
	Changes in our asset retirement obligations were as follows (in millions):
		Year Ended December 31,
		2012			2011			2010
	Balance as of beginning of year	$	76		$	72		$	70
	Additions to accrual	2			2			1
	Accretion expense	4			4			4
	Settlements	(4		)	(2		)	(3		)
	Foreign currency translation	1			—			—
	Balance as of end of year	$	79		$	76		$	72
	Other
	Other accrued expenses include contingent lease accruals, unearned revenue related to our heating oil operations and contingent liabilities related to legal matters and for claims for indirect taxes that are both probable and reasonably estimable.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure	COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES
	Tax Matters	Leases
	We are subject to extensive tax liabilities imposed by multiple jurisdictions, including income taxes, indirect taxes (excise/duty, sales/use and gross receipts taxes), payroll taxes, franchise taxes, withholding taxes and ad valorem taxes. New tax laws and regulations and changes in existing tax laws and regulations are continuously being enacted or proposed that could result in increased expenditures for tax liabilities in the future. Many of these liabilities are subject to periodic audits by the respective taxing authority. Subsequent changes to our tax liabilities as a result of these audits may subject us to interest and penalties.	We have long-term operating lease commitments for land for retail sites, office facilities, retail site buildings and related equipment that generally contain renewal options for periods ranging from five to ten years. In addition to minimum rental payments, certain leases require additional contingent payments based on motor fuel volume sold. We also have capital lease commitments for certain retail sites as described in Note 6. In most cases, we expect that in the normal course of business, our leases will be renewed or replaced by other leases.
	Litigation Matters	As of December 31, 2012, our future minimum lease payments for (i) operating leases having initial or remaining noncancelable lease terms in excess of one year and (ii) capital leases were as follows (in millions):
	We are party to claims and legal proceedings arising in the ordinary course of business. We have not recorded a loss contingency liability with respect to some of these matters because we have determined that it is remote that a loss has been incurred. For other matters, we have recorded a loss contingency liability where we have determined that it is probable that a loss has been incurred and that the loss is reasonably estimable. These loss contingency liabilities are not material to our financial position. We re-evaluate and update our loss contingency liabilities as matters progress over time, and we believe that any possible loss in excess of amounts already recorded will not be material to our results of operations, financial position or liquidity.
	There have been no significant changes to the litigation matters discussed in Note 9 of our combined financial statements for the year ended December 31, 2012, which are included in the Form 10.
			Operating		Capital
			Leases		Leases
		2013	$	23	$	2
		2014	18		1
		2015	15		1
		2016	12		1
		2017	9		—
		Thereafter	26		3
		Total minimum rental payments	$	103	8
		Less amount representing interest			(3		)
		Net minimum rental payments			$	5
		Rental expense was as follows (in millions):
			Year Ended December 31,
			2012		2011			2010
		Minimum rental expense	$	25	$	25		$	25
		Contingent rental expense	23		23			23
		Total rental expense	$	48	$	48		$	48
		Litigation Matters
		We are party to claims and legal proceedings arising in the ordinary course of business. We have not recorded a loss contingency liability with respect to some of these matters because we have determined that it is remote that a loss has been incurred. For other matters, we have recorded a loss contingency liability where we have determined that it is probable that a loss has been incurred and that the loss is reasonably estimable. These loss contingency liabilities are not material to our financial position. We re-evaluate and update our loss contingency liabilities as matters progress over time, and we believe that any possible loss in excess of amounts already recorded will not be material to our results of operations, financial position or liquidity, except for the litigation matters discussed below.
		MTBE Litigation
		As of December 2012, we were named in four cases alleging liability related to methyl-tertiary butyl ether (“MTBE”) contamination in groundwater.  The plaintiffs are generally water providers, governmental authorities and private water companies alleging that refiners, marketers or retailers of MTBE and gasoline containing MTBE are liable for manufacturing or distributing a defective product. Three of the cases are pending in federal court and are consolidated for pre-trial proceedings in the U.S. District Court for the Southern District of New York (Multi-District Litigation Docket No. 1358, In re: Methyl-Tertiary Butyl Ether Products Liability Litigation). One case is pending in state court.
		We have recorded a loss contingency liability with respect to our MTBE litigation portfolio; however, we believe it is reasonably possible that we may suffer a loss in excess of the amount recorded that could have a material adverse effect on our results of operations, financial position or liquidity. An estimate of the possible loss or range of loss in excess of the amount accrued due to an adverse result in all or substantially all of these cases cannot reasonably be made because of a number of factors, including uncertainties regarding the scope of the contamination, an incomplete discovery process with respect to our contribution to the contamination (if any) and the inherent uncertainty of litigation. It should be noted, however, that Valero will fully indemnify us for these matters in connection with the separation and the distribution, which is discussed in Note 1.
		Temperature Adjusted Fuel Complaints
		On December 13, 2006, a class action complaint was filed against Valero, Shell Oil Products Company LLC, ConocoPhillips, Chevron USA, Inc., Tesoro Refining and Marketing Company, Wal-Mart Stores, Inc., Costco Wholesale Corporation, The Kroger Company and a few other retailers in San Francisco federal court. The complaint accused the defendants of violating state consumer protection laws by failing to adjust the volume or price of fuel when the fuel temperature exceeded 60 degrees Fahrenheit. Following this filing, numerous other federal complaints were filed and consolidated in the U.S. District Court for the District of Kansas (Multi-District Litigation Docket No. 1840, In re: Motor Fuel Temperature Sales Practices Litigation). In mid-April 2012, Valero and certain of the other defendants reached a preliminary class settlement with the plaintiffs. On September 28, 2012, the court initially denied approval of this settlement concluding that the settling parties had failed to show how the settlement sufficiently benefited the class members. The settling parties, including Valero, agreed with the court and supplemented the record to demonstrate how the settlement will benefit the class. On December 10, 2012, the court approved the settlement. We had recorded an immaterial loss contingency liability with respect to this matter consistent with our liability under the settlement; therefore, we have no additional exposure due to the court’s approval of the settlement.
		Because a portion of Valero’s alleged liability in the class action allegedly arises out of our retail operations, we have agreed to indemnify Valero for 50% of the monetary portion of the settlement (or otherwise 50% of any monetary payment that Valero ultimately may be obligated to pay in final resolution of the class action). We have also agreed to certain actions required under the settlement agreement on a prospective basis, including the posting of fuel temperatures at our U.S. retail sites. The settlement agreement includes a full release from liability for Valero and its affiliates, including us.
		Canadian Price Fixing Claims
		Ultramar Ltd., Valero’s principal Canadian subsidiary (“Ultramar”), was named as a defendant in four class actions alleging that Ultramar and other competitors engaged in illegal price fixing in four distinct markets in the province of Québec. The cases were filed in June 2008 following a guilty plea by Ultramar and an employee and charges laid against several alleged co-conspirators. As a result, four class actions were filed on the same day in the matters of (i) Simon Jacques vs Ultramar et al in the Superior Court of Québec, District of Québec City, (ii) Daniel Thouin/ Marcel Lafontaine vs Ultramar et al, Superior Court of Québec, District of Montreal, (iii) Michael Jeanson et al vs Ultramar et al, Superior Court of Québec, District of Hull and (iv) Thibeau vs Ultramar et al, Superior Court of Québec, District of Montreal. As required pursuant to the civil procedure rules in effect, the first filed claim is given priority, and the others are suspended pending final judgment on the first filed claim. The guilty plea followed an extensive government investigation and was confined to a limited time period and limited geographic area around Thetford Mines and Victoriaville in Québec.  The plaintiffs attempted to widen the scope, alleging the existence of a conspiracy extending between 2002 and 2008 throughout Québec.  The court allowed a time range of 2002 to 2006 but did not expand the geographic area beyond the four limited markets identified by the investigation.  A hearing on class suitability took place in September 2009, and in November 2009, the court authorized the action to proceed on a class basis for the limited geographic area discussed above.  A statement of claim was filed but the proceedings were suspended until May 5, 2011.  The suspension was a result, in part, of damage proof issues for plaintiffs that developed pre-discovery.  The court required the plaintiffs to file a report on damages on May 5, 2011. Ultramar intends to vigorously contest the scope of alleged liability and damages.
		On June 10, 2011, Ultramar was served with a “new” amended motion to institute a class action in the matter of Daniel Thouin/Marcel Lafontaine v. Ultramar Ltd., et al., Superior Court of Québec, District of Québec. This matter had previously been put in abeyance to allow the first filed claim discussed above to proceed. The plaintiff changed the venue and the geographical scope of its recourse alleging that defendants colluded in other regions of Québec. By issuing this motion, the attorney for the plaintiff (the same as for the other price fixing matter) is trying to extend its claim outside the limited territory authorized by the court in the Jacques matter.  On September 6, 2012, the Superior Court of Québec granted the plaintiff’s motion to extend the scope of the territory to be covered by the action.
		Ultramar’s alleged liability in these claims arises entirely out of our retail operations in Canada. As a result, we expect that we will agree to indemnify and hold harmless Valero fully from any liability associated with these claims pursuant to the Separation and Distribution Agreement.
		During the fourth quarter of 2012, we concluded a loss was probable and reasonably estimable and as such, we recorded an immaterial loss contingency liability. Due to the inherent uncertainty of litigation, we believe it is reasonably possible that we may suffer a loss in excess of the amount recorded that could have a material adverse effect on our results of operations, financial position or liquidity with respect to one or more of the lawsuits. An estimate of the possible loss or range of loss from an adverse result in all or substantially all of these cases cannot be reasonably made due to a number of factors, the most significant of which is that no amount of damages has been specified by the plaintiffs.
		Environmental Matters
		We are subject to extensive federal, state, provincial and local environmental laws and regulations, including those relating to USTs, the release or discharge of materials into the air, water and soil, waste management, pollution prevention measures, the generation, storage, handling, use, transportation and disposal of hazardous materials, the exposure of persons to hazardous materials, greenhouse gas emissions and characteristics, composition, storage and sale of motor fuel, and the health and safety of our employees.
		We are required to make financial expenditures to comply with regulations governing USTs adopted by federal, state, provincial and local regulatory agencies. Pursuant to the Resource Conservation and Recovery Act of 1976, as amended, the U.S. Environmental Protection Agency has established a comprehensive regulatory program for the detection, prevention, investigation and cleanup of leaking USTs. State or local agencies are often delegated the responsibility for implementing the federal program or developing and implementing equivalent state or local regulations. We have a comprehensive program in place for performing routine tank testing and other compliance activities which are intended to promptly detect and investigate any potential releases. In addition, the U.S. Federal Clean Air Act and similar state laws impose requirements on emissions to the air from motor fueling activities in certain areas of the country, including those that do not meet state or national ambient air quality standards. These laws may require the installation of vapor recovery systems to control emissions of volatile organic compounds to the air during the motor fueling process. We believe we are in compliance in all material respects with applicable environmental requirements, including those applicable to our underground storage tanks.
		We are in the process of investigating and remediating contamination at a number of our sites as a result of recent or historic releases of motor fuel. In 2013, we expect to spend about $2 million on remediation projects and do not expect to exceed this amount in 2014 or 2015. In addition, we make routine applications to state trust funds for the sharing, recovering and reimbursement of certain cleanup costs and liabilities as a result of releases of motor fuel from storage systems.
		Because environmental laws and regulations are becoming more complex and stringent and new environmental laws and regulations are continuously being enacted or proposed, the level of future expenditures required for environmental matters could increase. In addition, any major upgrades in any of our operating facilities could require material additional expenditures to comply with environmental laws and regulations.
		Environmental exposures are difficult to assess and estimate for numerous reasons including the complexity and differing interpretations of governmental regulations, the lack of reliable data, the number of potentially responsible parties and their financial capabilities, the multiplicity of possible solutions and the duration of remedial and monitoring activity required. Accruals for environmental liabilities are recorded based on our best estimate using all information that is available at the time. Loss estimates are measured and liabilities are based on currently available facts, existing technology and presently enacted laws and regulations, taking into consideration the likely effects of inflation and other societal and economic factors. Also considered when measuring environmental liabilities are our prior experience in remediation of contaminated sites, other companies’ cleanup experience and data released by the relevant authority.
		Legislative and regulatory initiatives regarding climate change and greenhouse gas emissions have accelerated recently in the U.S. and Canada. Greenhouse gases are certain gases, including carbon dioxide, that may be contributing to global warming and other climatic changes. If governmental climate change or greenhouse gas reduction initiatives are enacted, they could have a material adverse impact on our business, financial condition and results of operations by increasing our regulatory compliance expenses, increasing our motor fuel costs and/or decreasing customer demand for motor fuel sold at our locations. For example, the California Global Warming Solutions Act, also known as AB 32, directs the California Air Resources Board (“CARB”) to develop and issue regulations to reduce greenhouse gas emissions in California to 1990 levels by 2020. CARB has issued a variety of regulations aimed at reaching this goal, including a Low Carbon Fuel Standard, a statewide cap-and-trade program and electricity renewable standards. CARB is also intending to require the establishment of Clean Fuels Outlets for alternative fuel vehicles. In addition, the Canadian province of Québec enacted a regulation creating a cap-and-trade system that will apply to us starting on January 1, 2015. To the degree these programs or greenhouse gas regulations increase cost that we are unable to recover or otherwise adversely impact consumer demand, these matters could have a material adverse effect on our financial position, results of operations and liquidity.
		Self-Insurance Matters
		We are partially self-insured for our general liability insurance. We maintain insurance coverage at levels that are customary and consistent with industry standards for companies of similar size. We are a nonsubscriber under the Texas Workers’ Compensation Act and maintain an employee injury plan in compliance with the Employee Retirement Income Security Act of 1974 in the U.S., which is self-insured. For our U.S. operations outside of Texas, we maintain statutory workers’ compensation insurance, which is partially self-insured. In Canada, we are a subscriber under the public system workers’ compensation of the provinces where we operate. As of December 31, 2012, there are a number of outstanding claims that are of a routine nature. The estimated incurred but unpaid liabilities relating to these claims are included in other accrued expenses. Additionally, there are open claims under previous policies that have not been resolved as of December 31, 2012. While the ultimate outcome of these claims cannot presently be determined, management believes that the accrued liability of $17 million will be sufficient to cover the related liability and that the ultimate disposition of these claims will have no material effect on our financial position and results of operations. Valero will fully indemnify us for these and similar matters that may be incurred up to the date of the separation and the distribution, which is discussed in Note 1.
		We were insured under Valero’s insurance policies for occurrences prior to the completion of the distribution. The specifications and insured limits under those policies, however, were at a level consistent with Valero as a whole. As a result, we were effectively self-insured and were exposed to most losses relating to occurrences prior to the completion of the distribution. We obtained comprehensive insurance coverage subsequent to the completion of the distribution, but we may incur losses that are not covered by insurance or reserves, in whole or in part, and such losses could adversely affect our financial position and results of operations.
		Tax Matters
		We are subject to extensive tax liabilities imposed by multiple jurisdictions, including income taxes, indirect taxes (excise/duty, sales/use and gross receipts taxes), payroll taxes, franchise taxes, withholding taxes and ad valorem taxes. New tax laws and regulations and changes in existing tax laws and regulations are continuously being enacted or proposed that could result in increased expenditures for tax liabilities in the future. Many of these liabilities are subject to periodic audits by the respective taxing authority. Subsequent changes to our tax liabilities as a result of these audits may subject us to interest and penalties.
		Health Care Reform
		In March 2010, a comprehensive health care reform package composed of the Patient Protection and Affordable Care Act and the Health Care and Education Reconciliation Act of 2010 (“Health Care Reform”) was enacted into law in the U.S. Provisions of the Health Care Reform are expected to affect the future costs of the U.S. health care plans. We expect to receive more guidance on the Health Care Reform provisions, which are required in 2014 and will then be able to better evaluate the potential impact of the Health Care Reform on our financial position and results of operations; however, we currently estimate that our annual health care costs will increase by approximately $5 million in 2014.

Stockbased_Compensation

Stock-based Compensation	12 Months Ended
	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments	STOCK-BASED COMPENSATION
	Overview
	CST did not have any stock compensation plans prior to adoption of the 2013 CST Brands, Inc. Omnibus Stock Incentive Plan. Instead, our eligible employees participated in Valero’s 2011 Omnibus Stock Incentive Plan (the “OSIP”), which authorized the grant of stock and stock-based awards. Awards available under the OSIP included options to purchase shares of common stock of Valero and restricted stock that vests over a period determined by Valero’s compensation committee. Prior to the approval of the OSIP by Valero’s stockholders, most of the equity awards granted to our employees were made under Valero’s 2005 Omnibus Stock Incentive Plan and 2003 Employee Stock Incentive Plan.
	Up to the completion of the separation and the distribution described in Note 1, our employees participated in Valero’s stock-based compensation plans. No stock-based awards of CST were issued in exchange for either vested or non-vested Valero stock-based awards held by our employees prior to the separation. Valero charges us for the estimated fair value of stock-based awards related to our employees as that expense is recognized by Valero.
	Total stock-based compensation expense charged to us was as follows (in millions):
		Year Ended December 31,
		2012		2011		2010
	Stock-based compensation expense	$	2	$	3	$	2
	As of December 31, 2012, Valero had $2 million of unrecognized stock-based compensation cost that it expected to charge to us over the remaining vesting period (approximately two years). However, Valero accelerated the vesting of restricted stock awards held by our employees on or prior to the record date. As a result, we were charged for the remaining unrecognized stock-based compensation related to those awards at that time.
	Performance shares held by CST employees were forfeited pursuant to the provisions in the performance share agreements between Valero and the affected employees. With respect to stock options to purchase Valero stock held by CST employees, Valero has adjusted the exercise prices and the number of shares subject thereto to reflect the impact of the distribution, as more particularly set forth in the Employee Matters Agreement. Any future expense related to these options will be recorded by Valero.
	Summary of Valero’s Stock-Based Compensation Plans
	Stock Options
	Under the terms of Valero’s various stock-based compensation plans, the exercise price of options granted is not less than the fair market value of Valero’s common stock on the date of grant. Stock options become exercisable pursuant to the individual written agreements between the participants and Valero, usually in three or five equal annual installments beginning one year after the date of grant, with unexercised options generally expiring seven or ten years from the date of grant.
	The fair value of stock options granted during 2012 was estimated using the Monte Carlo simulation model, as these options contain both a service condition and a market condition in order to be exercised. Prior to 2012, the fair value of stock options were valued at the date of grant using the Black-Scholes option pricing model. Compensation cost is recognized on a straight-line basis, net of estimated forfeitures, over the requisite service period.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2012
Postemployment Benefits [Abstract]
Postemployment Benefits Disclosure	EMPLOYEE BENEFIT PLANS
	Overview
	Our employees were employees of Valero until completion of the separation and the distribution from Valero described in Note 1. As a result, our employees participated in certain defined benefit and defined contribution plans sponsored by Valero. Valero charged us for all benefit costs associated with our employees and carried the obligations for employee benefit plans in its financial statements. Our share of those costs was charged to us through affiliate billings and reflected in operating expenses and general and administrative expenses.
	Because we were not the plan sponsor of these plans, our combined balance sheets do not reflect any assets or liabilities related to these plans.
	Following the completion of the separation and the distribution, our active employees no longer participate in benefit plans sponsored or maintained by Valero, and instead participate in our benefit plans. No assets and/or liabilities under Valero’s plans were transferred to us following completion of the separation and the distribution.
	The information below is limited to amounts associated with our employees.
	Valero’s Defined Benefit Plans
	Valero is the sponsor of the defined benefit pension plans that cover certain of our employees. These plans provide eligible employees with retirement income based primarily on years of service and compensation during specific periods. Valero funds the pension plans as required by local regulations. The assets of the plans are held by major financial institutions and are well diversified and include investments in domestic and international equities, mutual funds, corporate debt instruments, government securities, common collective trusts, insurance contracts and cash and cash equivalents.
	Valero also provides health care and life insurance benefits for certain retired employees through its postretirement benefit plans. Certain of our employees become eligible if, while still working for us, they reach normal retirement age or take early retirement. These plans are unfunded, and retired employees share the cost of the health care benefits.
	For our allocation of benefit costs, we recorded expense as follows (in millions):
		Year Ended December 31,
		2012		2011		2010
	U.S. pension cost	$	2	$	1	$	1
	Canadian pension cost	2		2		2
	U.S. postretirement benefit cost	—		—		—
	Summary of Valero’s Defined Contribution Plans
	Valero Savings Plan
	Valero is the sponsor of the Valero Savings Plan, which covered certain of our U.S. employees. Under this plan, participants contributed from 1% to 30% of their eligible compensation. Valero contributes $0.60 for every $1.00 of the participant’s contribution up to 6% of eligible compensation. At Valero’s discretion, it may also make profit-sharing contributions, which can range from 3.5% to 5% of eligible compensation, to the plan to be allocated to the participants.
	Valero Energy Corporation Thrift Plan
	Valero is the sponsor of the Valero Energy Corporation Thrift Plan, which covered our U.S. employees who are not covered by the Valero Savings Plan. Employees are immediately eligible to participate in the plan and receive employer matching contributions. Valero matched 100% of participant contributions up to 6% of each participant’s total annual salary, excluding cash bonuses.
	Ultramar Ltd. Savings Plan
	Valero is the sponsor of the Ultramar Ltd. Savings Plan, which covered all of our Canadian employees. Permanent employees are eligible after three months of service, temporary employees are eligible after one year of service, and seasonal employees are eligible after 220 days of services during 36 consecutive months. Valero contributed 9% of the employee’s base salary plus 50% of the employee’s voluntary contribution, which is limited to 6% of base salary. Valero’s contribution does not exceed 12% of the base salary.
	For our allocation of benefit costs, we recorded expense as follows (in millions):
		Year Ended December 31,
		2012		2011		2010
	Valero Savings Plan	$	7	$	5	$	6
	Valero Energy Corporation Thrift Plan	1		1		1
	Ultramar Ltd. Savings Plan	3		3		3

Income_Taxes

Income Taxes	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Income Taxes Disclosure	INCOME TAXES	INCOME TAXES
	Our effective income tax rate for the three and six months ended June 30, 2013 was 43% and 39%, respectively, compared with 34% and 33% for the corresponding periods of 2012. The effective tax rate differs from the federal statutory rate of 35% primarily due to state income taxes and the impact of foreign operations. Also impacting our effective tax rate for the second quarter and first six months of 2013 was a $7 million deferred tax expense we recorded resulting from the loss of certain state tax credits that were no longer eligible for use in our consolidated tax return as a result of the separation and distribution, which represented a 10% and 7% component of the effective rate for the three and six months ended June 30, 2013, respectively.	Income before income tax expense from our U.S. and Canadian operations was as follows (in millions):
	The provision for income taxes for periods prior to the separation and distribution were computed as if we were a stand-alone company.
			Year Ended December 31,
			2012			2011			2010
		U.S. operations	$	202		$	160		$	157
		Canadian operations	113			157			133
		Income before income tax expense	$	315		$	317		$	290
		The following is a reconciliation of income tax expense to income taxes computed by applying the U.S. statutory federal income tax rate (35% for all years presented) to income before income tax expense (in millions):
			Year Ended December 31,
			2012			2011			2010
		Federal income tax expense	$	110		$	111		$	101
		at the U.S. statutory rate
		U.S. state income tax expense,	4			4			4
		net of U.S. federal income tax effect
		Canadian operations	(9		)	(11		)	(7		)
		Credits	—			(1		)	(1		)
		Income tax expense	$	105		$	103		$	97
		Components of income tax expense related to net income were as follows (in millions):
			Year Ended December 31,
			2012			2011			2010
		Current:
		U.S. federal	$	67		$	40		$	44
		U.S. state	6			5			4
		Canada	33			46			43
		Total current	106			91			91
		Deferred:
		U.S. federal	1			14			8
		U.S. state	—			1			1
		Canada	(2		)	(3		)	(3		)
		Total deferred	(1		)	12			6
		Income tax expense	$	105		$	103		$	97
		The tax effects of significant temporary differences representing deferred income tax assets and liabilities were as follows (in millions):
			December 31,
			2012			2011
		Deferred income tax assets:
		Tax credit carryforwards	$	8		$	8
		Net operating losses (“NOLs”)	1			1
		Environmental liabilities	1			1
		Inventories	10			10
		Other assets	16			17
		Total deferred income tax assets	36			37
		Less: Valuation allowance	(1		)	(1		)
		Net deferred income tax assets	35			36
		Deferred income tax liabilities:
		Property and equipment	(145		)	(147		)
		Other	—			(1		)
		Total deferred income tax liabilities	(145		)	(148		)
		Net deferred income tax liabilities	$	(110	)	$	(112	)
		We had the following income tax credit and loss carryforwards as of December 31, 2012 (in millions):
			Amount			Expiration
		U.S. state income tax credits	$	12		2026
		U.S. state NOL (gross amount)	16			2018
		We have recorded a valuation allowance as of December 31, 2012 due to uncertainties related to our ability to utilize our state NOLs. The valuation allowance is based on our estimates of future taxable income in the various jurisdictions in which we operate and the period over which deferred income tax assets will be recoverable. The realization of net deferred income tax assets recorded as of December 31, 2012 is primarily dependent upon our ability to generate future taxable income in certain U.S. states.
		Subsequently recognized tax benefits in the amount of $1 million related to the valuation allowance for deferred income tax assets as of December 31, 2012 will be allocated as an income tax benefit.
		Deferred income taxes have not been provided on the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and the respective tax bases of our Canadian subsidiaries based on the determination that such differences are essentially permanent in duration in that the earnings of these subsidiaries are expected to be indefinitely reinvested in the Canadian operations. If these earnings were not considered indefinitely reinvested, deferred income taxes would have been recorded after consideration of U.S. foreign tax credits. The decision by us to forgo these elections could significantly increase our income tax expense. It is not practicable to estimate the amount of additional tax that might be payable on those earnings, if distributed.
		As of December 31, 2012 and 2011, we did not have any unrecognized tax benefits.
		Our financial results are included in the U.S. and Canada consolidated tax returns of Valero prior to the separation and distribution. As such, with the exception of certain states, we did not make cash tax payments directly to taxing jurisdictions; rather, our share of Valero’s tax payments are reflected as changes in “Net parent investment.” Direct cash payments for certain state income taxes were approximately $1 million for the year ended December 31, 2012 and less than $1 million in each of the years ended December 31, 2011 and 2010.

Debt

Debt	6 Months Ended
	Jun. 30, 2013
Debt Disclosure [Abstract]
Debt Disclosure	DEBT
	Our balances for long-term debt and capital leases are as follows (in millions):
			June 30,			December 31,
			2013			2012
	5.00% senior notes due 2023		$	550		$	—
	Term loan due 2018 (effective rate of 1.95% at June 30, 2013)		500			—
	Capital leases		4			5
	Total debt outstanding		1,054			5
	Less current portion		(29		)	(1		)
	Debt, less current portion		$	1,025		$	4
	Availability under revolving credit facility (expires 2018):
	Total available credit facility limit		$	300		$	—
	Letters of credit outstanding		(3		)	—
	Maximum leverage ratio constraint (a)		(99		)	—
	Total available and undrawn		$	198		$	—
	(a)	Our credit facility contains a maximum lease adjusted leverage ratio of 3.75 to 1.00. As a result, we were limited to the amount we could borrow under our revolving credit facility at June 30, 2013.
	In connection with the issuance of our new long-term debt, we incurred debt issuance and credit facility origination costs of $18 million, which is amortized into interest expense using the effective interest method over the terms of the associated notes and credit facilities.
	Notes
	Our $550 million notes are guaranteed, jointly and severally, on a senior unsecured basis by certain of our domestic subsidiaries. The notes and the guarantees are unsecured senior obligations of CST and the guarantor subsidiaries, respectively. Accordingly, they are: equal in right of payment with all of our and the guarantors’ existing and future senior unsecured indebtedness; senior in right of payment to any of our and the guarantors’ future subordinated indebtedness; effectively subordinated to all of our and the guarantors’ existing and future secured indebtedness, including indebtedness under our new credit facilities; and effectively subordinated to all future indebtedness and other liabilities, including trade payables, of our non-guarantor subsidiaries (other than indebtedness and other liabilities owed to us).
	If we sell certain assets and do not repay certain debt or reinvest the proceeds of such sales within certain periods of time, we will be required to use such proceeds to offer to repurchase the notes at 100% of their principal amount, plus accrued and unpaid interest and special interest, if any, to the date of repurchase. Upon the occurrence of certain specific change of control events, we will be required to offer to repurchase all outstanding notes at 101% of the aggregate principal amount of notes repurchased, plus accrued and unpaid interest, if any, to the date of repurchase.
	The indenture governing the notes, among other things, imposes limitations on our ability to: borrow money or guarantee debt; create liens; pay dividends on or redeem or repurchase stock; make specified types of investments and acquisitions; enter into new lines of business; enter into transactions with affiliates; and sell assets or merge with other companies.
	The notes were issued in a private transaction that was not subject to the registration requirements of the Securities Act of 1933 (the “Securities Act”). In connection with the offering of the notes, we entered into a registration rights agreement pursuant to which we and the guarantors of the notes will register substantially identical exchange notes under the Securities Act and permit holders to exchange the notes for the registered exchange notes.
	Credit Facilities
	Our new credit facilities provide for an aggregate amount of $800 million in financing, with a final maturity date on May 1, 2018, consisting of the following:
	•	a term loan facility in an aggregate principal amount of $500 million; and
	•	a revolving credit facility in an aggregate principal amount of up to $300 million.
	The credit facilities are guaranteed by our domestic subsidiaries and secured by security interests and liens on substantially all of our domestic subsidiaries’ assets, including 100% of the capital stock of our domestic subsidiaries and 65% of the voting equity interests and 100% of the non-voting equity interests of material, first-tier, foreign subsidiaries, subject to certain customary exceptions. The credit facilities have, among others, the following terms:
	•	subject to exclusions, mandatory prepayments with the net cash proceeds of certain asset sales, insurance proceeds or condemnation awards, the incurrence of certain indebtedness and our excess cash flow (as defined in the credit agreement);
	•	customary affirmative and negative covenants for credit agreements of this type, including limitations on us and our guarantor subsidiaries with respect to indebtedness, liens, fundamental changes, restrictive agreements, prepayments and amendments of certain indebtedness, dispositions of assets, acquisitions and other investments, sale leaseback transactions, conduct of business, transactions with affiliates and dividends and redemptions or repurchases of stock; and
	•	financial covenants consisting of (a) a maximum total lease adjusted leverage ratio initially set at 3.75 to 1.00, (b) a minimum fixed charge coverage ratio set at 1.30 to 1.00, and (c) limitations on expansion capital expenditures. As of June 30, 2013, our lease adjusted leverage ratio and fixed charge coverage ratio were 3.24 and 5.56, respectively.
	Borrowings under our credit facilities bear interest at the “London Interbank Offered Rate” (“LIBOR”) plus a margin, or an alternate base rate as defined under the agreement, plus a margin. Initially, all LIBOR rate loans have an applicable interest rate margin of 1.75%, and all alternate base rate loans have an applicable interest rate margin of 0.75%. Future interest rate margins will increase or decrease based on our leverage ratio as prescribed under the credit agreement governing the credit facilities. The revolving credit facility provides for customary fees, including commitment fees and other fees.
	Outstanding borrowings under our term loan facility are LIBOR loans bearing interest at 1.95% (LIBOR plus 1.75%) as of June 30, 2013.
	We are required to make principal payments on the term loan in accordance with an amortization schedule as follows (in millions):
	Years Ending December 31,		Total Principal to be Repaid
	2013 (remainder)		$	12
	2014		34
	2015		47
	2016		69
	2017		75
	2018		263
	Total		$	500
	The aggregate fair value and carrying amount of the notes and term loan at June 30, 2013 was $1.04 billion and $1.05 billion, respectively. The fair value of our debt is determined primarily using the market approach based on quoted prices provided by third-party brokers and vendor pricing services, but are not exchange-traded. These quoted prices are considered Level 2 inputs under the fair value hierarchy established by ASC 820, Fair Value Measurements and Disclosures.

Related_Party

Related Party	6 Months Ended										12 Months Ended
	Jun. 30, 2013										Dec. 31, 2012
Related Party Transactions [Abstract]
Related party transactions disclosure	RELATED-PARTY TRANSACTIONS										RELATED-PARTY TRANSACTIONS
	Purchased Motor Fuel										Related-party transactions include the purchase of motor fuel from Valero, fees charged by Valero for processing credit card transactions on our behalf, the allocation of medical and life insurance costs, stock-based compensation allocations, employee benefit plan allocations and certain corporate functions performed by Valero. Motor fuel purchased by us from Valero is recorded as a component of cost of sales based on transfer price formulas that vary from terminal to terminal. The actual prices we pay typically change daily, based on market fluctuations. Valero charged us a percentage of credit card sales or, for certain transactions, a percentage as well as a fixed amount per credit card transaction, which we recorded as a component of cost of sales. Medical insurance, life insurance, stock-based compensation and employee benefit plan expenses were allocated to us based on Valero’s determination of actual costs attributable to our employees and are recorded as components of operating expenses and general and administrative expenses. As discussed in Note 1, certain corporate functions performed by Valero on our behalf were charged to us based primarily on specific identification of time and/or activities associated with CST, employee headcount or capital expenditures. We recorded these corporate allocations as a component of general and administrative expenses and believe that the amount allocated to us is a reasonable approximation of the costs related to CST. However, such related-party transactions cannot be presumed to be carried out on an arm’s-length basis as the requisite conditions of competitive, free-market dealings may not exist. For purposes of these financial statements, payables and receivables related to transactions between us and Valero are included as a component of the net parent investment.
	Motor fuel purchased by us from Valero is recorded as a component of cost of sales based on price formulas that vary from terminal to terminal. The actual prices we pay typically change daily, based on market fluctuations of wholesale motor fuel in the geographic locations where we purchase our motor fuel for resale.										The following table reflects significant transactions with related parties (in millions):
	Under the U.S. Fuel Supply Agreements and the Petroleum Product Supply Agreement in Canada, we purchase a substantial portion of our motor fuel from Valero at “per-terminal,” market-based prices. The pricing formulas under our supply agreements changed effective January 1, 2013 and our cost of sales increased as a result of differences in price formulas from those historically charged prior to the separation and distribution. These differences in price formulas increased our cost of sales $2 million and $3 million in Retail–U.S. and Retail–Canada, respectively, during the three months ended June 30, 2013 and $4 million and $6 million in Retail–U.S. and Retail–Canada, respectively, during the six months ended June 30, 2013. In addition, the U.S. Fuel Supply Agreements and the Petroleum Product Supply Agreement in Canada differ from our arrangements prior to the separation and distribution by providing for payment terms of “net 10” days after taking title to the motor fuel versus “on delivered” payment. These new payment terms became effective at the time of the separation and distribution. Due to the change in payment terms, our cash increased by $342 million during the six months ended June 30, 2013.
	Medical insurance, life insurance, and employee benefit plan expenses
	Valero allocated these costs to us based on Valero’s determination of actual costs attributable to our employees, which we recorded as components of operating expenses and general and administrative expenses for all periods presented. In connection with the separation and distribution, we entered into an Employee Matters Agreement between us and Valero. The Employee Matters Agreement governs Valero’s and our compensation and employee benefit obligations with respect to the current and former employees of each company, and generally allocates liabilities and responsibilities relating to employee compensation and benefit plans and programs. In connection with the separation and distribution, we recognized a $15 million receivable from Valero in connection with Valero’s agreement to indemnify us for self-insurance obligations that we incurred up to and including the distribution date.												Year Ended December 31,
	Certain corporate functions												2012			2011			2010
	As discussed in Note 1, certain corporate functions performed by Valero on our behalf were charged to us based primarily on specific identification of time and/or activities associated with CST, employee headcount or capital expenditures. We recorded these corporate allocations as a component of general and administrative expenses in the combined and consolidated statements of income.										Cost of sales		$	10,810		$	10,533		$	8,170
	Transition services agreements
	In connection with the separation and distribution, we entered into two Transition Services Agreements: one between CST Brands, Inc. and Valero and one between our Canadian subsidiary and Valero. The Transition Services Agreements set forth the terms on which Valero provides to us, and we provide to Valero, on a temporary basis, certain services or functions that the companies historically have shared. Transition services include administrative, payroll, human resources, data processing, environmental health and safety, financial audit support, financial transaction support, legal support services, IT and network infrastructure systems and various other support and corporate services. The Transition Services Agreements provide for the provision of specified transition services generally for a period of up to eighteen months, on a cost or a cost-plus basis. We record the fee Valero charges us for these services as a component of general and administrative expenses.										Operating expenses (a)		43			36			35
	We believe that the operating expenses and general and administrative expenses allocated to us and included in the accompanying combined statements of income were a reasonable approximation of the costs related to CST’s operations. However, such related-party transactions cannot be presumed to be carried out on an arm’s-length basis as the requisite conditions of competitive, free-market dealings may not exist. For purposes of these financial statements, payables and receivables related to transactions between us and Valero, prior to the separation and distribution, are included as a component of the net parent investment. Subsequent to the separation and distribution, payables and receivables between us and Valero are shown as “Accounts Payable to Valero” on our consolidated balance sheet.
	The following table reflects significant transactions with Valero (in millions):										General and administrative expenses (a)		36			36			33
		Three Months Ended					Six Months Ended				(a)	Includes stock-based compensation and employee benefit plan expense allocations that are more fully described in Notes 10 and 11, respectively.
		June 30,					June 30,				Net Parent Investment
		2013			2012		2013		2012		The following is a reconciliation of the amounts presented as “Net transfers to Parent” on our statements of changes in net investment and the amounts presented as “Net transfers to Parent” on our statements of cash flows.
	Cost of sales	$	2,632		$	2,688	$	5,288	$	5,390
	Operating expenses	4			11		14		21				Year Ended December 31,
													2012			2011			2010
	General and administrative expenses	5			9		12		17		Net transfers to Parent per statements of changes in net investment		$	(222	)	$	(151	)	$	(221	)
											Non-cash transactions:
	We did not have any significant transactions with any other related parties.										Transfers of assets to Parent		3			1			1
	Net Parent Company Investment
	The following is a reconciliation of amounts presented as “Net transfers to Valero” on the consolidated and combined statement of stockholders’ equity and “Net transfers to Valero” on the consolidated and combined statement of cash flows for the six months ended June 30, 2013 (in millions):										Net transfers of cash to Parent per statements of cash flows		$	(219	)	$	(150	)	$	(220	)
	Net transfers to Valero per the consolidated and combined statement of stockholders’ equity	$	(731	)
	Non-cash adjustments:
	Net transfers of assets and liabilities with Valero	353
	Net transfers to Valero per the consolidated and combined statements of cash flows	$	(378	)

Segment_Information

Segment Information	6 Months Ended													12 Months Ended
	Jun. 30, 2013													Dec. 31, 2012
Segment Reporting [Abstract]
Segment Reporting Disclosure	SEGMENT INFORMATION													SEGMENT INFORMATION
	We have two reportable segments: Retail–U.S. and Retail–Canada. The Retail–U.S. segment includes convenience stores located in the United States. The Retail–Canada segment includes convenience stores, filling stations, cardlock locations and heating oil operations located in Canada. Operating revenues from our heating oil business were less than 5% of our consolidated operating revenues for the three and six months ended June 30, 2013 and have been included within the Retail–Canada segment information.													We have two reportable segments: Retail–U.S. and Retail–Canada. The Retail–U.S. segment includes convenience stores located in the U.S. The Retail–Canada segment includes convenience stores, filling stations, cardlocks and heating oil operations. Our heating oil operations are not significant and have been included within the Retail–Canada segment information. General and administrative expenses that are not included in either of the two reportable segments are included in the corporate category.
	The reportable segments are strategic business units that experience different operating income margins due to geographic supply and demand attributes and specific country and local regulatory environments. Performance is evaluated based on operating income. There are no intersegment revenues. No single customer accounted for more than 10% of our consolidated and combined operating revenues.													The reportable segments are strategic business units that experience different operating income margins due to geographic supply and demand and country and local regulatory environments. They are managed separately as each business requires unique marketing strategies that address country-specific operating requirements. Performance is evaluated based on operating income. There are no intersegment revenues.
	The following table reflects activity related to our reportable segments (in millions):													The following table reflects activity related to segment operating income (in millions):
		Three Months Ended						Six Months Ended							Retail–		Retail–		Corporate			Total
		June 30,						June 30,							U.S.		Canada
		2013			2012			2013			2012			Year ended December 31, 2012:
	Operating revenues													Operating revenues from external customers	$	7,907	$	5,228	$	—		$	13,135
	Retail–U.S.	$	2,007		$	2,044		$	3,935		$	3,948
														Depreciation, amortization and accretion expense	78		37		—			115
	Retail–Canada	1,204			1,301			2,464			2,609
														Operating income (loss)	246		130		(61		)	315
	Total	$	3,211		$	3,345		$	6,399		$	6,557
														Total expenditures for long-lived assets	181		42		—			223
	Depreciation, amortization and accretion expense
	Retail–U.S.	$	21		$	20		$	42		$	38
														Year ended December 31, 2011:
	Retail–Canada	9			9			18			18			Operating revenues from external customers	7,557		5,306		—			12,863
	Total	$	30		$	29		$	60		$	56		Depreciation, amortization and accretion expense	76		37		—			113
	Operating income (loss)													Operating income (loss)	202		174		(59		)	317
	Retail–U.S.	$	68		$	132		$	86		$	139
														Total expenditures for long-lived assets	91		39		—			130
	Retail–Canada	33			46			59			73
	General and administrative expense	(20		)	(14		)	(35		)	(29		)	Year ended December 31, 2010:
	Total	$	81		$	164		$	110		$	183		Operating revenues from external customers	6,183		4,188		—			10,371
	Income before income taxes													Depreciation, amortization and accretion expense	71		34		—			105
	Operating income	$	81		$	164		$	110		$	183
														Operating income (loss)	197		149		(57		)	289
	Other income, net	1			—			2			—
														Total expenditures for long-lived assets	68		37		—			105
	Interest expense	(7		)	—			(7		)	—
														Operating revenues from external customers for our principal products were as follows (in millions):
	Income before income tax expense	$	75		$	164		$	105		$	183
	Capital expenditures														Year Ended December 31,
	Retail–U.S.	$	40		$	20		$	78		$	35			2012		2011		2010
														Motor fuel sales (gasoline and diesel)	$	11,047	$	10,758	$	8,443
	Retail–Canada	10			9			12			11
														Merchandise sales	1,496		1,484		1,445
	Total	$	50		$	29		$	90		$	46
														Other	592		621		483
	Operating revenues for our principal products were as follows (in millions):
														Total operating revenues	$	13,135	$	12,863	$	10,371
		Three Months Ended						Six Months Ended						Operating revenues by geographic area are shown in the table below (in millions). The geographic area is based on location of customer, and no single customer accounted for more than 10% of our combined operating revenues.
		June 30,						June 30,
		2013			2012			2013			2012
	Motor fuel sales	$	2,701		$	2,815		$	5,342		$	5,477			Year Ended December 31,
															2012		2011		2010
	Merchandise sales	399			385			751			731			U.S.	$	7,907	$	7,557	$	6,183
	Other	111			145			306			349			Canada	5,228		5,306		4,188
	Total operating revenues	$	3,211		$	3,345		$	6,399		$	6,557		Total operating revenues	$	13,135	$	12,863	$	10,371
	Other operating revenues are derived from our heating oil business as well as revenues from car wash and commissions from lottery, money orders, air/water/vacuum services, video and game rentals and access to ATMs.													Long-lived assets include property and equipment and intangible assets. Geographic information by country for long-lived assets consisted of the following (in millions):
	Long-lived assets include property and equipment, goodwill and intangible assets. Geographic information by country for long-lived assets consisted of the following (in millions):
															December 31,
		June 30,			December 31,										2012		2011
		2013			2012									U.S.	$	938	$	836
	U.S.	$	971		$	938
														Canada	379		364
	Canada	356			379
														Total long-lived assets	$	1,317	$	1,200
	Total long-lived assets	$	1,327		$	1,317
														Total assets by reportable segment were as follows (in millions):
	Total assets by reportable segment were as follows (in millions):
															December 31,
		June 30,			December 31,										2012		2011
	2013			2012									Retail–U.S.	$	1,153	$	1,132
Retail–U.S.	$	1,463		$	1,153
													Retail–Canada	555		558
Retail–Canada	779			555
													Corporate	1		1
Corporate	65			1
													Total assets	$	1,709	$	1,691
Total assets	$	2,307		$	1,709
													Total assets by reportable segment were as follows (in millions):
														December 31,
														2012		2011
													Retail–U.S.	$	1,153	$	1,132
													Retail–Canada	555		558
													Corporate	1		1
													Total assets	$	1,709	$	1,691

Supplemental_Cash_Flows_Inform

Supplemental Cash Flows Information	6 Months Ended								12 Months Ended
	Jun. 30, 2013								Dec. 31, 2012
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Disclosure	SUPPLEMENTAL CASH FLOW INFORMATION								SUPPLEMENTAL CASH FLOW INFORMATION
	In order to determine net cash provided by operating activities, net income is adjusted by, among other things, changes in current assets and current liabilities as follows (in millions):								In order to determine net cash provided by operating activities, net income is adjusted by, among other things, changes in current assets and current liabilities as follows (in millions):
			Six Months Ended								Year Ended December 31,
			June 30,								2012			2011			2010
			2013			2012			Decrease (increase) in current assets:
	Increase (decrease) in current assets:								Receivables, net		$	41		$	(30	)	$	(11	)
	Receivables, net		$	(69	)	$	7
									Inventories		(5		)	(5		)	(3		)
	Inventories		3			14			Prepaid expenses and other		2			(4		)	—
	Prepaid expenses and other		(6		)	—			Increase (decrease) in current liabilities:
									Accounts payable		4			(2		)	7
	Increase (decrease) in current liabilities:
	Accounts payable		1			(1		)	Accrued expenses		(3		)	(4		)	(1		)
									Taxes other than income taxes		3			5			20
	Accounts payable to Valero		342			—
									Changes in current assets and current liabilities		$	42		$	(40	)	$	12
	Accrued expenses		4			(5		)
									The above changes in current assets and current liabilities differ from changes between amounts reflected in the applicable balance sheets for the respective periods for the following reasons:
	Taxes other than income taxes		(67		)	7
									•	the amounts shown above exclude changes in cash, deferred income taxes and current portion of capital lease obligations;
	Income taxes payable		9			—
									•	amounts accrued for capital expenditures are reflected in investing activities when such amounts are paid; and
	Changes in current assets and current liabilities		$	217		$	22
									•	certain differences between balance sheet changes and the changes reflected above result from translating foreign currency denominated amounts at the applicable exchange rates as of each balance sheet date.
	The above changes in current assets and current liabilities differ from changes between amounts reflected in the applicable balance sheets for the respective periods for the following reasons:								There were no significant noncash investing and financing activities for the years ended December 31, 2012, 2011 and 2010.
									Cash flows related to interest and income taxes were as follows (in millions):
	•	amounts accrued for capital expenditures are reflected in investing activities when such amounts are paid; and
	•	certain differences between balance sheet changes and the changes reflected above result from translating foreign currency denominated amounts at the applicable exchange rates as of each balance sheet date.									Year Ended December 31,
	We made interest payments of $1 million for the six months ended June 30, 2013. We issued the$550 million notes to Valero in connection with the separation and distribution and Valero transferred the notes to a third-party lender to satisfy certain of Valero’s then-outstanding debt obligations. As a result, we did not receive cash proceeds related to the $550 million notes.										2012			2011			2010
	We issued 75,397,241 shares of our common stock to Valero and Valero’s stockholders in connection with the separation and distribution. As a result, we did not receive cash proceeds from the issuance of our common stock.								Interest paid		$	1		$	1		$	1
	There were no significant interest payments, noncash investing or financing activities for the six months ended June 30, 2012.
	As consolidated subsidiaries of Valero, our financial results were included in the U.S. and Canada consolidated tax returns of Valero. As such, with the exception of certain states, we did not make cash tax payments directly to taxing jurisdictions; rather, our share of Valero’s tax payments were reflected as changes in “Net parent investment.” Direct cash payments for certain state income taxes were less than $1 million during the six months ended June 30, 2013 and 2012.								Income taxes paid, net		106			91			91
									Our financial results are included in the U.S. and Canada consolidated tax returns of Valero prior to the separation and distribution. As such, with the exception of certain states, we did not make cash tax payments directly to taxing jurisdictions; rather, our share of Valero’s tax payments are reflected as changes in “Net parent investment.” Direct cash payments for certain state income taxes were approximately $1 million for the year ended December 31, 2012 and less than $1 million in each of the years ended December 31, 2011 and 2010. As a result, the amounts reflected as “income taxes paid, net” represent the current portion of income tax expense for the respective year.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	6 Months Ended											12 Months Ended
	Jun. 30, 2013											Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure	GOODWILL AND INTANGIBLE ASSETS											INTANGIBLE ASSETS
	Goodwill and intangible assets consisted of the following (in millions):											Intangible assets, net consisted of the following (in millions):
		Gross Carrying Amount				Accumulated Amortization							Gross Carrying Amount				Accumulated Amortization
		June 30,		December 31,		June 30,			December 31,				December 31,				December 31,
		2013		2012		2013			2012				2012		2011		2012			2011
	Goodwill	$	18	$	—							Customer list	$	124	$	120	$	(85	)	$	(74	)
	Intangible assets:											Other	3		2		(1		)	(1		)
	Customer lists and other	120		127		$	(85	)	$	(86	)
												Total	$	127	$	122	$	(86	)	$	(75	)
	Total	$	138	$	127	$	(85	)	$	(86	)
												All of our intangible assets are subject to amortization and are amortized on a straight-line basis primarily over five to 15 years. Amortization expense for intangible assets was $8 million, $8 million and $7 million for the years ended December 31, 2012, 2011 and 2010, respectively. The estimated aggregate amortization expense for the years ending December 31, 2013 through December 31, 2016 is $8 million per year and $1 million for the year ending December 31, 2017.
	The Customer lists and other relate primarily to our Retail–Canada segment. Therefore, the historical gross carrying amounts are translated at each balance sheet date, resulting in changes to historical amounts presented.
	Goodwill is not amortized, but instead is tested for impairment at the reporting unit level at least annually, and tested for impairment more frequently if events and circumstances indicate that the goodwill might be impaired. The annual impairment test of goodwill is performed as of the first day of the fourth quarter of our fiscal year.
	In performing our annual impairment analysis, ASC 350–20, Intangibles–Goodwill and Other, allows us to use qualitative factors to determine whether it is more likely than not (likelihood of more than 50%) that the fair value of a reporting unit is less than its carrying amount, including goodwill.
	If, after assessing the totality of events or circumstances, we determine that it is more likely than not that the fair value of a reporting unit exceeds its carrying amount, no further testing is necessary. However, if we determine that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, then we perform the first step of the two-step goodwill impairment test.
	In the first step of the goodwill impairment test, the reporting unit’s carrying amount (including goodwill) and its fair value are compared. If the estimated fair value of a reporting unit is less than the carrying value, a second step is performed to compute the amount of the impairment by determining an “implied fair value” of goodwill. The determination of our “implied fair value” requires us to allocate the estimated fair value of the reporting unit to the assets and liabilities of the reporting unit. Any unallocated fair value represents the “implied fair value” of goodwill, which is compared to the corresponding carrying value. If the “implied fair value” is less than the carrying value, an impairment charge would be recorded.

Equity

Equity	6 Months Ended
	Jun. 30, 2013
Equity [Abstract]
Stockholders' Equity Note Disclosure	EQUITY
	Share Activity
	As of June 30, 2013, a total of 250 million shares of common stock, $0.01 par value, were authorized, of which 75,397,241 were issued and outstanding.
	Stock-based compensation
	Prior to the separation and distribution, Valero allocated stock-based compensation costs to us based on Valero’s determination of actual costs attributable to our employees. No stock-based awards of CST were issued in exchange for either vested or non-vested Valero stock-based awards held by our employees prior to the distribution. Valero accelerated the vesting of all of its non-vested restricted stock awards held by CST employees, including its named executive officers, in connection with the separation and distribution. As a result, we were charged for the remaining unrecognized stock-based compensation related to those awards at that time, which was $1 million.
	Performance shares held by CST employees were forfeited pursuant to the provisions in the performance share agreements between Valero and the affected employees. With respect to stock options to purchase Valero stock held by CST employees, Valero has adjusted the exercise prices and the number of shares subject thereto to reflect the impact of the distribution, as more particularly set forth in the Employee Matters Agreement.
	In anticipation of the distribution, Valero, as sole stockholder of CST, and the CST Board of Directors approved the 2013 CST Brands, Inc. Omnibus Stock Incentive Plan (the “Plan”). The Plan permits us to grant stock options, stock appreciation rights, restricted stock, restricted stock shares, other stock-based awards and cash awards to CST officers, directors and certain other employees. Under the Plan, stock-based grants can be made up to a maximum of 8 million shares of our common stock. We granted the following stock-based awards in the second quarter of 2013 under the Plan:
			Actual Number of Awards			Weighted-Average Grant-Date Fair Value
	Stock options		228,885			$	11.78
	Restricted stock		199,283			$	29.68
	As of June 30, 2013, there were approximately 7.6 million shares available for grant under the Plan.
	Compensation expense for stock-based awards is based on the fair values of the awards on the date of grant and is recognized on a straight-line basis over the vesting period of each vesting tranche. We record stock-based compensation as components of operating expenses and administrative expenses in the consolidated and combined statements of income. We recognized $2 million of stock-based compensation during the three and six months ended June 30, 2013, including the $1 million allocated to us by Valero.
	Stock Options
	Stock options granted under the Plan become exercisable in equal increments on the first, second and third anniversaries of their date of grant, and expire on the tenth anniversary of their date of grant. Exercise prices of these stock options are equal to the market value of the common stock on the date of grant. Market value is defined by the Plan as the mean of the highest and lowest prices per share of our stock on the New York Stock Exchange on the date of grant. The weighted-average exercise price of stock options granted under the Plan was $29.77.
	The fair value of each option was estimated on the date of grant using the Black-Scholes option-pricing model based on the exercise price and market value on the date of grant, and assumptions, including term, stock price volatility, risk-free interest rate and dividend yield. Expected term was estimated using the simplified method, which takes into account vesting and contractual term. The simplified method is being used to calculate expected term due to the lack of prior grant history and relatively small number of recent expected life assumptions available from our peers. Expected stock price volatility was based on the weighted average of our peer group’s median implied volatility, our own mean reversion volatility, and the median of our peer group’s most recent volatilities over the expected term. The risk-free interest rate was based on the rate of a zero-coupon U.S. Treasury instrument with a remaining term approximately equal to the expected term. The risk free rate was calculated by interpolating between the published 5-year and 7-year U.S. Treasury spot rates. The expected dividend yield was based on the market value of the common stock on the date of grant (as defined by the Plan) and assumed future annual dividends over the expected term.
	As of June 30, 2013, there was $2 million of total unrecognized compensation cost related to unvested stock options.  This cost is expected to be recognized over a weighted-average period of approximately 1.9 years.
	Restricted Stock
	Restricted stock granted under the Plan vest under one of the following schedules:
	•	in full on the first anniversary of their date of grant;
	•	in full on the third anniversary of their date of grant; or
	•	in three equal increments on the first, second and third anniversaries of their date of grant.
	The fair value of each share of restricted stock is estimated on the date of grant as the mean of the highest and lowest prices per share of our stock price on the New York Stock Exchange on the date of grant. As of June 30, 2013, there was $5 million of total unrecognized compensation cost related to restricted stock. This cost is expected to be recognized over a weighted-average period of approximately 2.2 years.
	Comprehensive Income
	Comprehensive income for a period encompasses net income and all other changes in equity other than from transactions with our stockholders. Foreign currency translation adjustments are the only component of our accumulated other comprehensive income. Our other comprehensive loss before reclassifications results from foreign currencies (the Canadian dollar) that devalued from the U.S. dollar. Changes in foreign currency translation adjustment were as follows for the three and six months ended June 30, 2013 (in millions):
			Three Months Ended				Six Months Ended
			June 30,				June 30,
			2013				2013
	Balance at the beginning of the period		$	155			$	165
	Other comprehensive loss before reclassifications		(20		)		(30		)
	Amounts reclassified from other comprehensive income		—				—
	Net other comprehensive loss		(20		)		(30		)
	Balance at the end of the period		$	135			$	135

Fair_Value

Fair Value

6 Months Ended

12 Months Ended

Jun. 30, 2013

Dec. 31, 2012

Fair Value Disclosures [Abstract]

Fair Value Disclosures

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS

General

General

U.S. GAAP defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. U.S. GAAP requires the disclosure of the fair values of all financial instruments, regardless of whether they are recognized at their fair values or carrying amounts in our balance sheets.

GAAP requires that certain financial instruments, such as derivative instruments, be recognized at their fair values in our balance sheets. However, other financial instruments, such as debt obligations, are not required to be recognized at their fair values, but GAAP provides an option to elect fair value accounting for these instruments. GAAP requires the disclosure of the fair values of all financial instruments, regardless of whether they are recognized at their fair values or carrying amounts in our balance sheets. For financial instruments recognized at fair value, GAAP requires the disclosure of their fair values by type of instrument, along with other information, including changes in the fair values of certain financial instruments recognized in income or other comprehensive income. We had no financial instruments, however, that were required to be recognized at their fair values in our balance sheets as of December 31, 2012 or 2011. For financial instruments not recognized at fair value, the disclosure of their fair values is provided below under “Other Financial Instruments.”

U.S. GAAP provides a framework for measuring fair value and establishes a three-level fair value hierarchy that prioritizes inputs to valuation techniques based on the degree to which objective prices in external active markets are available to measure fair value. Following is a description of each of the levels of the fair value hierarchy.

Nonfinancial assets, such as property and equipment, and nonfinancial liabilities are recognized at their carrying amounts in our balance sheets. GAAP does not permit nonfinancial assets and liabilities to be remeasured at their fair values. However, GAAP requires the remeasurement of such assets and liabilities to their fair values upon the occurrence of certain events, such as the impairment of property and equipment. In addition, if such an event occurs, GAAP requires the disclosure of the fair value of the asset or liability along with other information, including the gain or loss recognized in income in the period the remeasurement occurred. This information is provided below under “Nonrecurring Fair Value Measurements.”

GAAP provides a framework for measuring fair value and establishes a three-level fair value hierarchy that prioritizes inputs to valuation techniques based on the degree to which objective prices in external active markets are available to measure fair value. Following is a description of each of the levels of the fair value hierarchy.

•

Level 1–Observable inputs, such as unadjusted quoted prices in active markets for identical assets or liabilities.

•

Level 1 - Observable inputs, such as unadjusted quoted prices in active markets for identical assets or liabilities.

•

Level 2–Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active.

•

Level 2 - Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active.

•

Level 3–Unobservable inputs for the asset or liability for which there is little, if any, market activity at the measurement date. Unobservable inputs reflect our own assumptions about what market participants would use to price the asset or liability. The inputs are developed based on the best information available in the circumstances, which might include occasional market quotes or sales of similar instruments or our own financial data such as internally developed pricing models, discounted cash flow methodologies, as well as instruments for which the fair value determination requires significant judgment.

During the six months ended June 30, 2013, there were no transfers between the fair value hierarchy levels.

•

Level 3 - Unobservable inputs for the asset or liability for which there is little, if any, market activity at the measurement date. Unobservable inputs reflect our own assumptions about what market participants would use to price the asset or liability. The inputs are developed based on the best information available in the circumstances, which might include occasional market quotes or sales of similar instruments or our own financial data such as internally developed pricing models, discounted cash flow methodologies, as well as instruments for which the fair value determination requires significant judgment.

We do not have any financial instruments measured at fair value on our balance sheets for any of the years presented. Because of their maturities and/or variable interest rates, certain financial instruments have fair values approximating their carrying values. These instruments include cash and cash equivalents, accounts receivable and trade payables. The fair value disclosure related to our debt is located in Note 7.

The financial instruments and nonfinancial assets and liabilities included in our disclosure of fair value measurements are categorized according to the fair value hierarchy based on the inputs used to measure their fair values.

Nonfinancial assets, such as property, plant and equipment, and nonfinancial liabilities are recognized at their carrying amounts in our balance sheets. U.S. GAAP does not permit nonfinancial assets and liabilities to be remeasured at their fair values. However, U.S. GAAP requires the remeasurement of such assets and liabilities to their fair values upon the occurrence of certain events, such as the impairment of property, plant and equipment or goodwill. In addition, if such an event occurs, U.S. GAAP requires the disclosure of the fair value of the asset or liability along with other information, including the gain or loss recognized in income in the period the remeasurement occurred.

Nonrecurring Fair Value Measurements

The fair value disclosure related to our 2012 acquisition of Crackerbox is located in Note 2.

As discussed in Note 3, we concluded that certain of our retail sites were impaired as of December 31, 2011 and 2010. To estimate fair value of the convenience stores, we used an income approach reflecting internally developed discounted cash flows that included, among other things, our expectations of future cash flows based on sales volume, gross margins and operating expenses.

The table below presents the fair value (in millions) of our nonfinancial assets measured on a nonrecurring basis during the years ended December 31, 2011 and 2010, and categorized according to the fair value hierarchy of the inputs utilized by us to determine the fair values as of December 31, 2011 and 2010.

Fair Value Measurements Using

Quoted

Significant

Significant

Total

Total Loss

Prices in

Other

Unobservable

Fair Value

Recognized

Active

Observable

Inputs

as of

During the

Markets

Inputs

(Level 3)

December 31

Year Ended

(Level 1)

(Level 2)

December 31

2011:00:00

Property and equipment

$

—

$

—

$

1

$

1

$

3

2010:00:00

Property and equipment

—

—

2

2

5

There were no liabilities that were measured at fair value on a nonrecurring basis during the years ended December 31, 2012, 2011 and 2010.

Other Financial Instruments

Cash is a financial instrument that we recognize in our balance sheets at its carrying amount. The fair value of this financial instrument approximates its carrying amount due to the low level of credit risk (Level 1).

Quarterly_Financial_Data_Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2012
Quarterly Financial Data (Unaudited) [Abstract]
Quarterly Financial Information	QUARTERLY FINANCIAL DATA (Unaudited)
	The following table summarizes quarterly financial data for the years ended December 31, 2012 and 2011 (in millions).
		2012 Quarter Ended
		31-Mar		30-Jun		30-Sep		31-Dec
	Operating revenues	$	3,212	$	3,345	$	3,382	$	3,196
	Operating income	19		164		35		97
	Net income	15		108		23		64
		2011 Quarter Ended
		31-Mar		30-Jun		30-Sep		31-Dec
	Operating revenues	$	2,962	$	3,430	$	3,353	$	3,118
	Operating income	43		120		84		70
	Net income	31		80		55		48

Guarantor_Subsidiaries

Guarantor Subsidiaries	6 Months Ended																																12 Months Ended
	Jun. 30, 2013																																Dec. 31, 2012
Guarantor Subsidiaries [Abstract]
Condensed Financial Statements	GUARANTOR SUBSIDIARIES																																GUARANTOR SUBSIDIARIES
	CST Brands, Inc.’s (the “Parent Company”) wholly-owned, domestic subsidiaries (the “Guarantor Subsidiaries”) fully and unconditionally guarantee on a joint and several basis certain of the outstanding indebtedness of CST Brands, Inc. The following consolidating and combining schedules present financial information on a consolidated and combined basis in conformity with the SEC’s Regulation S-X Rule 3-10(f):																																In connection with the separation and distribution, CST Brands, Inc. (the “Parent Company”) issued $550 million aggregate principal amount of senior unsecured bonds which are fully and unconditionally guaranteed, on a joint and several basis, by its wholly-owned, domestic subsidiaries (the “Guarantor Subsidiaries”). The following combining schedules present financial information on a combined basis in conformity with the SEC’s Regulation S-X Rule 3-10(f):
																																	COMBINING BALANCE SHEETS
	COMBINING BALANCE SHEETS																																(Millions of Dollars)
	(Unaudited, Millions of Dollars)
																																		31-Dec-12
		30-Jun-13																																Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Combined
		Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Consolidated															ASSETS
	ASSETS																																Current assets:
	Current assets:																																Cash	$	—			$	44			$	17			$	—			$	61
	Cash	$	—			$	266			$	148			$	—			$	414
																																	Receivables, net	—				41				93				—				134
	Receivables, net	—				98				99				—				197
																																	Inventories	—				121				47				—				168
	Inventories	—				119				44				—				163
																																	Deferred income taxes	—				4				9				—				13
	Deferred income taxes	—				1				8				—				9
																																	Prepaid expenses and other	—				3				5				—				8
	Prepaid expenses and other	—				7				7				—				14
																																	Total current assets	—				213				171				—				384
	Total current assets	—				491				306				—				797
																																	Property and equipment, at cost	—				1,371				492				—				1,863
	Property and equipment, at cost	—				1,414				478				—				1,892
																																	Accumulated depreciation	—				(435		)		(152		)		—				(587		)
	Accumulated depreciation	—				(463		)		(155		)		—				(618		)
																																	Property and equipment, net	—				936				340				—				1,276
	Property and equipment, net	—				951				323				—				1,274
																																	Intangible assets, net	—				2				39				—				41
	Goodwill and intangible assets, net	—				20				33				—				53
																																	Other assets, net	—				3				5				—				8
	Investment in subsidiaries	1,610				—				—				(1,610		)		—
																																	Total assets	$	—			$	1,154			$	555			$	—			$	1,709
	Deferred income taxes	—				—				112				—				112
																																	LIABILITIES AND NET INVESTMENT
	Other assets, net	32				33				6				—				71															Current liabilities:
																																	Current portion of capital lease obligations	$	—			$	1			$	—			$	—			$	1
	Total assets	$	1,642			$	1,495			$	780			$	(1,610	)		$	2,307
																																	Accounts payable	—				52				43				—				95
	LIABILITIES AND STOCKHOLDERS’ EQUITY
	Current liabilities:																																Accrued expenses	—				22				18				—				40
	Current portion of debt and capital lease obligations	$	28			$	1			$	—			$	—			$	29
																																	Taxes other than income taxes	—				22				70				—				92
	Accounts payable	—				48				35				—				83
																																	Total current liabilities	—				97				131				—				228
	Accounts payable to Valero	(1		)		205				138				—				342
																																	Capital lease obligations, less current portion	—				4				—				—				4
	Accrued expenses	7				21				16				—				44
																																	Deferred income taxes	—				110				13				—				123
	Taxes other than income taxes	—				20				3				—				23
																																	Other long-term liabilities	—				77				30				—				107
	Income taxes payable	—				5				4				—				9
																																	Commitments and contingencies
	Total current liabilities	34				300				196				—				530
																																	Net investment:
	Debt and capital lease obligations, less current portion	1,022				3				—				—				1,025															Net parent investment	—				866				216				—				1,082
	Deferred income taxes	—				89				—				—				89															Accumulated other comprehensive income (AOCI)	—				—				165				—				165
	Intercompany payables (receivables)	20				(20		)		—				—				—															Total net investment	—				866				381				—				1,247
	Other long-term liabilities	15				68				29				—				112															Total liabilities and net investment	$	—			$	1,154			$	555			$	—			$	1,709
	Commitments and contingencies
	Stockholders’ equity:																																COMBINING BALANCE SHEETS (CONTINUED)
	Common stock	1				—				—				—				1															(Millions of Dollars)
	Additional paid-in capital (APIC)	395				1,038				544				(1,582		)		395
																																			31-Dec-11
	Retained earnings	20				17				11				(28		)		20																	Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
																																ASSETS
Accumulated other comprehensive income (AOCI)	135				—				—				—				135															Current assets:
																																Cash		$	116			$	16			$	132
Total stockholders’ equity	551				1,055				555				(1,610		)		551
																																Receivables, net		64				108				172
Total liabilities and stockholders’ equity	$	1,642			$	1,495			$	780			$	(1,610	)		$	2,307
																																Inventories		109				50				159
COMBINING BALANCE SHEETS (CONTINUED)
(Millions of Dollars)																																Deferred income taxes		3				9				12
																																Prepaid expenses and other		5				5				10
	31-Dec-12
	Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Combined															Total current assets		297				188				485
ASSETS
Current assets:																																Property and equipment, at cost		1,224				454				1,678
Cash	$	—			$	44			$	17			$	—			$	61
																																Accumulated depreciation		(390		)		(135		)		(525		)
Receivables, net	—				41				93				—				134															Property and equipment, net		834				319				1,153
Inventories	—				121				47				—				168															Intangible assets, net		2				45				47
Deferred income taxes	—				4				9				—				13															Other assets, net		1				5				6
Prepaid expenses and other	—				3				5				—				8															Total assets		$	1,134			$	557			$	1,691
Total current assets	—				213				171				—				384															LIABILITIES AND NET INVESTMENT
																																Current liabilities:
Property and equipment, at cost	—				1,371				492				—				1,863															Current portion of capital lease obligations		$	1			$	—			$	1
Accumulated depreciation	—				(435		)		(152		)		—				(587		)													Accounts payable		46				38				84
Property and equipment, net	—				936				340				—				1,276															Accrued expenses		18				23				41
Intangible assets, net	—				2				39				—				41															Taxes other than income taxes		19				67				86
Other assets, net	—				3				5				—				8															Total current liabilities		84				128				212
Total assets	$	—			$	1,154			$	555			$	—			$	1,709														Capital lease obligations, less current portion		5				—				5
LIABILITIES AND NET INVESTMENT																																Deferred income taxes		109				15				124
Current liabilities:
Current portion of capital lease obligations	$	—			$	1			$	—			$	—			$	1														Other long-term liabilities		75				26				101
Accounts payable	—				52				43				—				95															Commitments and contingencies
																																Net investment:
Accrued expenses	—				22				18				—				40															Net parent investment		861				233				1,094
Taxes other than income taxes	—				22				70				—				92															Accumulated other comprehensive income (AOCI)		—				155				155
Income taxes payable	—				—				—				—				—															Total net investment		861				388				1,249
Total current liabilities	—				97				131				—				228															Total liabilities and net investment		$	1,134			$	557			$	1,691
Capital lease obligations, less current portion	—				4				—				—				4
																																COMBINING STATEMENTS OF INCOME
Deferred income taxes	—				110				13				—				123															(Millions of Dollars)
Other long-term liabilities	—				77				30				—				107
																																	Year Ended December 31, 2012
Commitments and contingencies																																	Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Combined
Net investment:																																Operating revenues	$	—			$	7,907			$	5,228			$	—			$	13,135
Net parent investment	—				866				216				—				1,082
																																Costs and expenses:
Accumulated other comprehensive income (AOCI)	—				—				165				—				165															Cost of sales	—				7,185				4,815				—				12,000
Total net investment	—				866				381				—				1,247															Operating expenses	—				398				246				—				644
Total liabilities and net investment	$	—			$	1,154			$	555			$	—			$	1,709														General and administrative expenses	—				44				17				—				61
																																Depreciation, amortization and accretion expense	—				78				37				—				115
COMBINING STATEMENTS OF INCOME
(Unaudited, Millions of Dollars)																																Total costs and expenses	—				7,705				5,115				—				12,820
																																Operating income	—				202				113				—				315
	Six Months Ended June 30, 2013
	Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Consolidated and Combined															Other income, net	—				—				1				—				1
Operating revenues	$	—			$	3,935			$	2,464			$	—			$	6,399
																																Interest expense	—				(1		)		—				—				(1		)
Costs and expenses:
Cost of sales	—				3,608				2,266				—				5,874															Income before income tax expense	—				201				114				—				315
Operating expenses	—				200				120				—				320															Income tax expense	—				74				31				—				105
General and administrative expenses	1				26				8				—				35															Net income	$	—			$	127			$	83			$	—			$	210
Depreciation, amortization and accretion expense	—				42				18				—				60
Total costs and expenses	1				3,876				2,412				—				6,289
																																		Year Ended December 31, 2011
Operating income	(1		)		59				52				—				110																	Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
																																Operating revenues		$	7,557			$	5,306			$	12,863
Other income, net	—				—				2				—				2
																																Costs and expenses:
Interest expense	(7		)		—				—				—				(7		)													Cost of sales		6,893				4,842				11,735
Equity in earnings of subsidiaries	28				—				—				(28		)		—															Operating expenses		383				253				636
Income before income tax expense	20				59				54				(28		)		105															General and administrative expenses		42				17				59
Income tax expense	—				25				16				—				41															Depreciation, amortization and accretion expense		76				37				113
Net income	$	20			$	34			$	38			$	(28	)		$	64														Asset impairment losses		2				1				3
																																Total costs and expenses		7,396				5,150				12,546
																																Operating income		161				156				317
	Six Months Ended June 30, 2012
		Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined																						Other income, net		—				1				1
Operating revenues		$	3,948			$	2,609			$	6,557
																																Interest expense		(1		)		—				(1		)
Costs and expenses:
Cost of sales		3,577				2,396				5,973																						Income before income tax expense		160				157				317
Operating expenses		194				122				316																						Income tax expense		59				44				103
General and administrative expenses		21				8				29																						Net income		$	101			$	113			$	214
Depreciation, amortization and accretion expense		38				18				56
Total costs and expenses		3,830				2,544				6,374																						COMBINING STATEMENTS OF INCOME (CONTINUED)
																																(Millions of Dollars)
Operating income		118				65				183
Other income, net		—				—				—																								Year Ended December 31, 2010
																																		Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
Interest expense		—				—				—																						Operating revenues		$	6,183			$	4,188			$	10,371
Income before income tax expense		118				65				183																						Costs and expenses:
																																Cost of sales		5,540				3,770				9,310
Income tax expense		43				18				61
																																Operating expenses		372				233				605
Net income		$	75			$	47			$	122
																																General and administrative expenses		40				17				57
COMBINING STATEMENTS OF COMPREHENSIVE INCOME																																Depreciation, amortization and accretion expense		72				33				105
(Unaudited, Millions of Dollars)
																																Asset impairment losses		2				3				5
	Six Months Ended June 30, 2013																															Total costs and expenses		6,026				4,056				10,082
	Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Consolidated and Combined
Net income	$	20			$	34			$	38			$	(28	)		$	64														Operating income		157				132				289
Other comprehensive income (loss):																																Other income, net		1				1				2
Foreign currency translation adjustment	(30		)		—				—				—				(30		)
																																Interest expense		(1		)		—				(1		)
Other comprehensive income (loss) before income taxes	(30		)		—				—				—				(30		)
																																Income before income tax expense		157				133				290
Income taxes related to items of other comprehensive income	—				—				—				—				—
																																Income tax expense		57				40				97
Other comprehensive income (loss)	(30		)		—				—				—				(30		)
																																Net income		$	100			$	93			$	193
Comprehensive income	$	(10	)		$	34			$	38			$	(28	)		$	34
																																COMBINING STATEMENTS OF COMPREHENSIVE INCOME
																																(Millions of Dollars)
	Six Months Ended June 30, 2012
		Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined																							Year Ended December 31, 2012
Net income		$	75			$	47			$	122																						Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Combined
																																Net income	$	—			$	127			$	83			$	—			$	210
Other comprehensive income (loss):
Foreign currency translation adjustment		—				1				1																						Other comprehensive income (loss):
																																Foreign currency translation adjustment	—				—				10				—				10
Other comprehensive income (loss) before income taxes		—				1				1
																																Other comprehensive income (loss) before income taxes	—				—				10				—				10
Income taxes related to items of other comprehensive income		—				—				—
																																Income taxes related to items of other comprehensive income	—				—				—				—				—
Other comprehensive income (loss)		—				1				1
																																Other comprehensive income (loss)	—				—				10				—				10
Comprehensive income		$	75			$	48			$	123
																																Comprehensive income	$	—			$	127			$	93			$	—			$	220
COMBINING STATEMENTS OF CASH FLOWS
(Unaudited, Millions of Dollars)
	Six Months Ended June 30, 2013																																	Year Ended December 31, 2011
	Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Consolidated and Combined																	Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
Cash flows from operating activities:																																Net income		$	101			$	113			$	214
Net income	$	20			$	34			$	38			$	(28	)		$	64
																																Other comprehensive income (loss):
Adjustments to reconcile net income to net cash provided by (used in) operating activities:																																Foreign currency translation adjustment		—				(7		)		(7		)
Stock-based compensation expense	—				2				—				—				$	2
																																Other comprehensive income (loss) before income taxes		—				(7		)		(7		)
Depreciation, amortization and accretion expense	—				42				18				—				60
																																Income taxes related to items of other comprehensive income		—				—				—
Deferred income tax expense	—				5				3				—				8
																																Other comprehensive income (loss)		—				(7		)		(7		)
Changes in current assets and current liabilities	6				149				62				—				217
																																Comprehensive income		$	101			$	106			$	207
Equity in earnings of subsidiaries	(28		)		—				—				28				—
Other operating activities, net	—				—				—				—				—
Net cash provided by (used in) operating activities	(2		)		232				121				—				351																	Year Ended December 31, 2010
																																		Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
Cash flows from investing activities:																																Net income		$	100			$	93			$	193
Capital expenditures	—				(78		)		(12		)		—				(90		)
																																Other comprehensive income (loss):
Acquisition	—				—				(4		)		—				(4		)													Foreign currency translation adjustment		—				24				24
Proceeds from dispositions of property and equipment	—				—				—				—				—															Other comprehensive income (loss) before income taxes		—				24				24
Other investing activities, net	—				(1		)		(1		)		—				(2		)													Income taxes related to items of other comprehensive income		—				—				—
Net cash used in investing activities	—				(79		)		(17		)		—				(96		)													Other comprehensive income (loss)		—				24				24
Cash flows from financing activities:																																Comprehensive income		$	100			$	117			$	217
Proceeds from issuance of long-term debt	500				—				—				—				500
Debt issuance and credit facility origination costs	(18		)		—				—				—				(18		)
Intercompany funding	20				(20		)		—				—				—															COMBINING STATEMENTS OF CASH FLOWS
																																(Millions of Dollars)
Payments of capital lease obligations	—				(1		)		—				—				(1		)
Net transfers to Valero	(500		)		90				32				—				(378		)														Year Ended December 31, 2012
																																	Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Combined
Net cash provided by financing activities	2				69				32				—				103															Cash flows from operating activities:
																																Net income	$	—			$	127			$	83			$	—			$	210
Effect of foreign exchange rate changes on cash	—				—				(5		)		—				(5		)
																																Adjustments to reconcile net income to net cash provided by operating activities:
Net increase in cash	—				222				131				—				353															Depreciation, amortization and accretion expense	—				78				37				—				115
Cash at beginning of year	—				44				17				—				61															Deferred income tax expense (benefit)	—				1				(2		)		—				(1		)
Cash at end of period	$	—			$	266			$	148			$	—			$	414														Changes in current assets and current liabilities	—				20				22				—				42
COMBINING STATEMENTS OF CASH FLOWS (CONTINUED)																																Other operating activities, net	—				(2		)		—				—				(2		)
(Unaudited, Millions of Dollars)
																																Net cash provided by operating activities	—				224				140				—				364
	Six Months Ended June 30, 2012																															Cash flows from investing activities:
		Guarantor Subsidiaries				Non-Guarantor Subsidiaries					Combined																					Capital expenditures	—				(114		)		(42		)		—				(156		)
Cash flows from operating activities:
Net income		$	75			$	47				$	122																				Acquisition	—				(61		)		—				—				(61		)
Adjustments to reconcile net income to net cash provided by operating activities:																																Proceeds from dispositions of property and equipment	—				2				—				—				2
Stock-based compensation expense		1				—					$	1
																																Other investing activities, net	—				—				—				—				—
Depreciation, amortization and accretion expense		38				18					56
																																Net cash used in investing activities	—				(173		)		(42		)		—				(215		)
Deferred income tax expense (benefit)		(5		)		1			—		(4		)
																																Cash flows from financing activities:
Changes in current assets and current liabilities		(3		)		25					22																					Payments of capital lease obligations	—				(1		)		—				—				(1		)
Other operating activities, net		3				—					3																					Net transfers to Parent	—				(122		)		(97		)		—				(219		)
Net cash provided by operating activities		109				91					200																					Net cash used in financing activities	—				(123		)		(97		)		—				(220		)
Cash flows from investing activities:																																Effect of foreign exchange rate changes on cash	—				—				—				—				—
Capital expenditures		(35		)		(11		)			(46		)
Acquisitions		(61		)		—					(61		)																			Net increase (decrease) in cash	—				(72		)		1				—				(71		)
Proceeds from dispositions of property and equipment		1				1					2																					Cash at beginning of year	—				116				16				—				132
Other investing activities, net		—				—					—																					Cash at end of year	$	—			$	44			$	17			$	—			$	61
Net cash used in investing activities		(95		)		(10		)			(105		)
Cash flows from financing activities:
Payments of capital lease obligations		—				—					—																					COMBINING STATEMENTS OF CASH FLOWS (CONTINUED)
																																(Millions of Dollars)
Net transfers to Parent		(89		)		(83		)			(172		)
Net cash used in financing activities		(89		)		(83		)			(172		)
Effect of foreign exchange rate changes on cash		—				(1		)			(1		)																					Year Ended December 31, 2011
																																		Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
Net decrease in cash		(75		)		(3		)			(78		)																			Cash flows from operating activities:
Cash at beginning of year		116				16					132																					Net income		$	101			$	113			$	214
Cash at end of period		$	41			$	13				$	54																				Adjustments to reconcile net income to net cash provided
																																by operating activities:
COMBINING STATEMENT OF CHANGES IN EQUITY																																Depreciation, amortization and accretion expense		76				37				113
(Unaudited, Millions of Dollars)
																																Asset impairment losses		2				1				3
		Common Stock																APIC														Non-cash interest expense		1				—				1
		Parent Company			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated				Parent Company			Guarantor Subsidiaries		Non-Guarantor Subsidiaries			Eliminations			Consolidated
Balance as of December 31, 2012		$	—		$	—		$	—		$	—		$	—			$	—		$	—	$	—		$	—		$	—		Deferred income tax expense (benefit)		14				(2		)		12
Net income		—			—			—			—			—				—			—		—			—			—			Changes in current assets and current liabilities		(35		)		(5		)		(40		)
																																Other operating activities, net		5				—				5
Net transfers to Valero		—			—			—			—			—				—			—		—			—			—
																																Net cash provided by operating activities		164				144				308
Issuance of stock at the separation and distribution		1			—			—			—			1				(1		)			—			—			(1		)
																																Cash flows from investing activities:
Reclassification of net parent investment to APIC		—			—			—			—			—				395			1,038		544			(1,582		)	395			Capital expenditures		(91		)		(39		)		(130		)
																																Proceeds from dispositions of property and equipment		3				2				5
Stock-based compensation expense		—			—			—			—			—				1					—			—			1
																																Other investing activities, net		(1		)		(1		)		(2		)
Other comprehensive loss		—			—			—			—			—				—			—		—			—			—			Net cash used in investing activities		(89		)		(38		)		(127		)
																																Cash flows from financing activities:
Balance as of June 30, 2013		$	1		$	—		$	—		$	—		$	1			$	395		$	1,038	$	544		$	(1,582	)	$	395		Payments of capital lease obligations		(1		)		—				(1		)
																																Net transfers to Parent		(47		)		(103		)		(150		)
		Net Parent Investment																Retained Earnings														Net cash used in financing activities		(48		)		(103		)		(151		)
		Parent Company			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated				Parent Company			Guarantor Subsidiaries		Non-Guarantor Subsidiaries			Eliminations			Consolidated			Effect of foreign exchange rate changes on cash		—				—				—
Balance as of December 31, 2012		$	—		$	866		$	216		$	—		$	1,082			$	—		$	—	$	—		$	—		$	—
																																Net increase in cash		27				3				30
Net income		—			17			27			—			44				20			17		11			(28		)	20
																																Cash at beginning of year		89				13				102
Net transfers to Valero		395			155			301			(1,582		)	(731		)		—			—		—			—			—
																																Cash at end of year		$	116			$	16			$	132
Issuance of stock at the separation and distribution		—			—			—			—			—				—			—		—			—			—
Reclassification of net parent investment to APIC		(395		)	(1,038		)	(544		)	1,582			(395		)		—			—		—			—			—
Stock-based compensation expense		—			—			—			—			—															—
Other comprehensive loss		—			—			—			—			—							—		—						—			COMBINING STATEMENTS OF CASH FLOWS (CONTINUED)
																																(Millions of Dollars)
Balance as of June 30, 2013		$	—		$	—		$	—		$	—		$	—			$	20		$	17	$	11		$	(28	)	$	20
																																		Year Ended December 31, 2010
		AOCI																Total																Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
		Parent Company			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated				Parent Company			Guarantor Subsidiaries		Non-Guarantor Subsidiaries			Eliminations			Consolidated			Cash flows from operating activities:
Balance as of December 31, 2012		$	—		$	—		$	165		$	—		$	165			$	—		$	866	$	381		$	—		$	1,247		Net income		$	100			$	93			$	193
Net income		—			—			—			—			—				$	20		$	34	$	38		$	(28	)	$	64		Adjustments to reconcile net income to net cash provided
																																by operating activities:
Net transfers to Valero		—			—			—			—			—				$	395		$	155	$	301		$	(1,582	)	$	(731	)	Depreciation, amortization and accretion expense		72				33				105
Issuance of stock at the separation and distribution		—			—			—			—			—				$	—		$	—	$	—		$	—		$	—		Asset impairment losses		2				3				5
Reclassification of net parent investment to APIC		165			—			(165		)	—			—				$	165		$	—	$	(165	)	$	—		$	—		Deferred income tax expense (benefit)		9				(3		)		6
Stock-based compensation expense		—			—			—			—			—				$	1		$	—	$	—		$	—		$	1		Changes in current assets and current liabilities		(6		)		18				12
Other comprehensive loss		(30		)	—			—			—			(30		)		$	(30	)	$	—	$	—		$	—		$	(30	)	Other operating activities, net		1				1				2
Balance as of June 30, 2013		$	135		$	—		$	—		$	—		$	135			$	551		$	1,055	$	555		$	(1,610	)	$	551		Net cash provided by operating activities		178				145				323
																																Cash flows from investing activities:
																																Capital expenditures		(68		)		(37		)		(105		)
																																Proceeds from dispositions of property and equipment		2				1				3
																																Other investing activities, net		(1		)		(1		)		(2		)
																																Net cash used in investing activities		(67		)		(37		)		(104		)
																																Cash flows from financing activities:
																																Payments of capital lease obligations		(1		)		—				(1		)
																																Net transfers to Parent		(116		)		(104		)		(220		)
																																Net cash used in financing activities		(117		)		(104		)		(221		)
																																Effect of foreign exchange rate changes on cash		—				1				1
																																Net increase (decrease) in cash		(6		)		5				(1		)
																																Cash at beginning of year		95				8				103
																																Cash at end of year		$	89			$	13			$	102
																																COMBINING STATEMENTS OF CHANGES IN NET INVESTMENT
																																(Millions of Dollars)
																																	Accumulated Other Comprehensive Income										Net Parent Investment									Net Investment
																																	Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Combined				Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Combined			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Combined
																																Balance as of December 31, 2009	$	—		$	138		$	138			$	823		$	236		$	1,059		$	823		$	374		$	1,197
																																Net income	—			—			—				100			93			193			100			93			193
																																Net transfers to Parent	—			—			—				(116		)	(105		)	(221		)	(116		)	(105		)	(221		)
																																Other comprehensive income	—			24			24				—			—			—			—			24			24
																																Balance as of December 31, 2010	—			162			162				807			224			1,031			807			386			1,193
																																Net income	—			—			—				101			113			214			101			113			214
																																Net transfers to Parent	—			—			—				(47		)	(104		)	(151		)	(47		)	(104		)	(151		)
																																Other comprehensive income	—			(7		)	(7		)		—			—			—			—			(7		)	(7		)
																																Balance as of December 31, 2011	—			155			155				861			233			1,094			861			388			1,249
																																Net income	—			—			—				127			83			210			127			83			210
																																Net transfers to Parent	—			—			—				(122		)	(100		)	(222		)	(122		)	(100		)	(222		)
																																Other comprehensive income	—			10			10				—			—			—			—			10			10
																																Balance as of December 31, 2012	$	—		$	165		$	165			$	866		$	216		$	1,082		$	866		$	381		$	1,247

The_Separation_and_the_Distrib1

The Separation and the Distribution, Basis of Presentation Description of Business and Summary of Significant Accounting Policies (Policies)	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Basis of presentation	Basis of Presentation	Basis of Presentation
	CST was incorporated in November 2012 and, in connection with its incorporation, CST issued 1,000 shares of common stock, par value $0.01 per share, to Valero for $10. CST was formed solely in contemplation of the separation and distribution and, prior to May 1, 2013, had not commenced operations and had no material assets, liabilities or commitments.	As previously noted, CST was incorporated in November 2012 and, in connection with its incorporation, CST issued 1,000 shares of common stock, par value $0.01 per share, to Valero for $10. CST was formed solely in contemplation of the separation and distribution, had not commenced operations and had no material assets, liabilities or commitments prior to the separation and distribution.
	Prior to the separation and distribution, these financial statements reflect the combined historical financial position, results of operations and cash flows of Valero’s retail business in the U.S. and Canada that were owned by direct and indirect wholly-owned subsidiaries of Valero, including an allocable portion of Valero’s corporate costs. The legal transfer of the assets (including the equity interests of certain Valero subsidiaries), liabilities and operations of Valero’s retail business into CST occurred on May 1, 2013. However, for ease of reference, these consolidated and combined financial statements are referred to as those of CST. Unless otherwise stated or the context otherwise indicates, all references in these consolidated and combined financial statements to “us,” “our,” or “we” mean CST.	These combined financial statements were prepared in connection with the expected separation and distribution and are derived from the consolidated financial statements and accounting records of Valero. These statements reflect the combined historical financial position, results of operations and cash flows of CST and Valero’s retail business in the United States (“U.S.”) and Canada that were owned by direct and indirect wholly owned subsidiaries of Valero, including an allocable portion of Valero’s corporate costs. The legal transfer of the assets (including the equity interests of certain Valero subsidiaries), liabilities and operations of Valero’s retail business into CST occurred on May 1, 2013. However, for ease of reference, these combined financial statements are referred to as those of CST. Unless otherwise stated or the context otherwise indicates, all references in these combined financial statements to “us,” “our,” or “we” mean the retail business of Valero, which is referred to as CST.
	Neither of our segments carried out transactions with the other during the periods presented; therefore, there were no intercompany transactions or accounts to be eliminated in connection with the consolidation or combination of these operations.	The financial statements are presented as if Valero’s U.S. and Canadian retail operations had been combined for all years presented. Neither operation, however, carried out transactions with the other during the years presented; therefore, there were no intercompany transactions or accounts to be eliminated in connection with the combination of these operations. The assets and liabilities in the combined balance sheets have been reflected on a historical cost basis, as immediately prior to the separation and the distribution, and all of the assets and liabilities presented were wholly owned by Valero and were transferred within the Valero consolidated group. The combined statements of income also include expense allocations for certain corporate functions historically performed by Valero and not allocated to its operating segments, including allocations of general corporate expenses related to executive oversight, accounting, treasury, tax, legal, procurement and information technology. These allocations are based primarily on specific identification of time and/or activities associated with CST, employee headcount or capital expenditures. Our management believes the assumptions underlying the combined financial statements, including the assumptions regarding allocating general corporate expenses from Valero, are reasonable. Nevertheless, the combined financial statements may not include all of the actual expenses that would have been incurred had we been a stand-alone company during the years presented and may not reflect our combined financial position, results of operations and cash flows had we been a stand-alone company during the periods presented. Actual costs that would have been incurred if we had been a stand-alone company would depend on multiple factors, including organizational structure and strategic decisions made in various areas, including information technology and infrastructure.
	The unaudited combined financial statements are presented as if Valero’s retail businesses in the U.S. and Canada had been combined for all periods prior to the separation and distribution. The assets and liabilities in the combined balance sheets have been reflected on a historical cost basis, as immediately prior to the separation and distribution. All of the assets and liabilities presented were wholly owned by Valero and were transferred within the Valero consolidated group. The combined statements of income prior to the separation and distribution also include expense allocations for certain corporate functions historically performed by Valero and not allocated to its operating segments, including allocations of general corporate expenses related to executive oversight, accounting, treasury, tax, legal, procurement, human resources and information technology (“IT”). These allocations were based primarily on specific identification of time and/or activities associated with CST’s operations, employee headcount or capital expenditures. We believe the assumptions underlying the combined financial statements, including the assumptions regarding allocating general corporate expenses from Valero, are reasonable. Subsequent to the separation and distribution, Valero continues to perform certain of these corporate functions on our behalf, for which we are charged a fee, in accordance with the Transition Services Agreements. Nevertheless, the combined financial statements may not include all of the actual expenses that would have been incurred had we operated as a stand-alone company during the combined periods presented and may not reflect our combined financial position, results of operations and cash flows had we operated as a stand-alone company during the combined periods presented. Actual costs that would have been incurred if we had operated as a stand-alone company during the combined periods presented would depend on multiple factors, including organizational structure and strategic decisions made in various areas, including IT and related infrastructure.
Cash	Prior to the separation and distribution, we transferred cash to Valero daily and Valero funded our operating and investing activities as needed. Accordingly, cash held by Valero at the corporate level was not allocated to us. Cash presented on our combined balance sheet prior to the separation and distribution represented cash on hand at our convenience stores, cash that had not yet been transferred to Valero and cash held by us in automated teller machines (“ATMs”) in our Retail–Canada segment. We reflected transfers of cash to and from Valero’s cash management system as a component of net parent investment on our combined balance sheet, and these net transfers of cash were reflected as a financing activity in our combined statement of cash flows. We did not include any interest income on the net cash transfers to Valero.	Valero uses a centralized approach to cash management and the financing of its operations. We transfered cash to Valero daily and Valero funded our operating and investing activities as needed. Accordingly, cash held by Valero at the corporate level was not allocated to us for any of the years presented. Cash presented on our combined balance sheets represents cash on hand at our convenience stores, cash that had not yet been transferred to Valero and cash held by us in automated teller machines (“ATMs”). We reflected transfers of cash to and from Valero’s cash management system as a component of net parent investment on our combined balance sheets, and these net transfers of cash are reflected as a financing activity in our combined statements of cash flows. We also have not included any interest income on the net cash transfers to Valero.
Use of estimates		Use of Estimates
		The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported in the combined financial statements and accompanying notes. Actual results could differ from those estimates. On an ongoing basis, we review our estimates based on currently available information. Changes in facts and circumstances may result in revised estimates.

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Policies)	6 Months Ended
	Jun. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and intangible assets	Goodwill is not amortized, but instead is tested for impairment at the reporting unit level at least annually, and tested for impairment more frequently if events and circumstances indicate that the goodwill might be impaired. The annual impairment test of goodwill is performed as of the first day of the fourth quarter of our fiscal year.
	In performing our annual impairment analysis, ASC 350–20, Intangibles–Goodwill and Other, allows us to use qualitative factors to determine whether it is more likely than not (likelihood of more than 50%) that the fair value of a reporting unit is less than its carrying amount, including goodwill.
	If, after assessing the totality of events or circumstances, we determine that it is more likely than not that the fair value of a reporting unit exceeds its carrying amount, no further testing is necessary. However, if we determine that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, then we perform the first step of the two-step goodwill impairment test.
	In the first step of the goodwill impairment test, the reporting unit’s carrying amount (including goodwill) and its fair value are compared. If the estimated fair value of a reporting unit is less than the carrying value, a second step is performed to compute the amount of the impairment by determining an “implied fair value” of goodwill. The determination of our “implied fair value” requires us to allocate the estimated fair value of the reporting unit to the assets and liabilities of the reporting unit. Any unallocated fair value represents the “implied fair value” of goodwill, which is compared to the corresponding carrying value. If the “implied fair value” is less than the carrying value, an impairment charge would be recorded.

Acquisitions_Tables

Acquisitions (Tables)	6 Months Ended			12 Months Ended
	Jun. 30, 2013			Dec. 31, 2012
Business Combinations [Abstract]
Schedule of Business Acquisitions	The purchase price allocation of the acquisition of Crackerbox was determined based on the acquisition-date fair values of the assets acquired and is as follows (in millions):			The assets acquired were recognized at their acquisition-date estimated fair values as follows (in millions):
	Inventories	$	3	Inventories	$	3
	Property and equipment	38		Property and equipment	56
	Other assets	2		Other assets	2
	Goodwill	18		Total consideration	$	61
	Total consideration	$	61

Earnings_per_Common_Share_Tabl

Earnings per Common Share (Tables)	6 Months Ended
	Jun. 30, 2013
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table provides a reconciliation of basic and diluted earnings per common share computations for the three and six months ended June 30, 2013 and 2012 (in millions, except per share amounts):
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2013		2012		2013		2012
	Earnings per common share:
	Net income attributable to stockholders	$	43	$	108	$	64	$	122
	Weighted-average common shares outstanding (in thousands)	75,397		75,397		75,397		75,397
	Total earnings per share	$	0.57	$	1.43	$	0.84	$	1.62
	Earnings per common share - assuming dilution:
	Net income attributable to stockholders	$	43	$	108	$	64	$	122
	Weighted-average common shares outstanding (in thousands)	75,397		75,397		75,397		75,397
	Common equivalent shares:
	Restricted stock (in thousands)	10		—		5		—
	Weighted-average common shares outstanding - assuming dilution (in thousands)	75,407		75,397		75,402		75,397
	Earnings per common shares - assuming dilution	$	0.57	$	1.43	$	0.84	$	1.62

Receivables_Tables

Receivables (Tables)	12 Months Ended
	Dec. 31, 2012
Receivables [Abstract]
Schedule of Accounts Receivable	Receivables consisted of the following (in millions):
		December 31,
		2012			2011
	Trade receivables	$	115		$	147
	Other	21			27
		136			174
	Allowance for doubtful accounts	(2		)	(2		)
	Receivables, net	$	134		$	172
Schedule of Allowance for Doubtful Accounts	Changes in the allowance for doubtful accounts consisted of the following (in millions):
		Year Ended December 31,
		2012			2011			2010
	Balance as of beginning of year	$	2		$	2		$	2
	Increase in allowance charged to expense	—			1			1
	Accounts charged against the allowance, net of recoveries	—			(1		)	(1		)
	Balance as of end of year	$	2		$	2		$	2

Inventories_Tables

Inventories (Tables)	6 Months Ended					12 Months Ended
	Jun. 30, 2013					Dec. 31, 2012
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consisted of the following (in millions):					Inventories consisted of the following (in millions):
		June 30,		December 31,			December 31,
		2013		2012			2012		2011
	Convenience store merchandise	$	110	$	111	Convenience store merchandise	$	111	$	104
	Motor fuel (at LIFO)	51		56		Motor fuel (at LIFO)	56		54
	Supplies	2		1		Supplies	1		1
	Inventories	$	163	$	168	Inventories	$	168	$	159

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2012
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Major classes of property and equipment consisted of the following (in millions):
		December 31,
		2012			2011
	Land	$	387		$	339
	Retail site buildings	476			406
	Equipment	560			535
	Leasehold improvements	276			254
	Other	135			130
	Construction in progress	29			14
	Property and equipment, at cost	1,863			1,678
	Accumulated depreciation	(587		)	(525		)
	Property and equipment, net	$	1,276		$	1,153

Accrued_Expenses_and_Other_Lon1

Accrued Expenses and Other Long-term Liabilities (Tables)	12 Months Ended
	Dec. 31, 2012
Asset Retirement Obligations [Abstract]
Schedule of Accounts Payable and Accrued Liabilities	Accrued expenses and other long-term liabilities consisted of the following (in millions):
		Accrued Expenses						Other Long-Term
								Liabilities
		December 31,						December 31,
		2012			2011			2012			2011
	Wage and other employee-related liabilities	$	22		$	19		$	—		$	—
	Environmental liabilities	2			2			3			2
	Self-insurance accruals (see Note 9)	6			6			11			12
	Asset retirement obligations	2			2			77			74
	Other	8			12			16			13
	Accrued expenses and other long-term liabilities	$	40		$	41		$	107		$	101
Schedule of Asset Retirement Obligations	Changes in our asset retirement obligations were as follows (in millions):
		Year Ended December 31,
		2012			2011			2010
	Balance as of beginning of year	$	76		$	72		$	70
	Additions to accrual	2			2			1
	Accretion expense	4			4			4
	Settlements	(4		)	(2		)	(3		)
	Foreign currency translation	1			—			—
	Balance as of end of year	$	79		$	76		$	72

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments	As of December 31, 2012, our future minimum lease payments for (i) operating leases having initial or remaining noncancelable lease terms in excess of one year and (ii) capital leases were as follows (in millions):
		Operating		Capital
		Leases		Leases
	2013	$	23	$	2
	2014	18		1
	2015	15		1
	2016	12		1
	2017	9		—
	Thereafter	26		3
	Total minimum rental payments	$	103	8
	Less amount representing interest			(3		)
	Net minimum rental payments			$	5
Schedule of Rent Expense	Rental expense was as follows (in millions):
		Year Ended December 31,
		2012		2011			2010
	Minimum rental expense	$	25	$	25		$	25
	Contingent rental expense	23		23			23
	Total rental expense	$	48	$	48		$	48

Stockbased_Compensation_Tables

Stock-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan	Total stock-based compensation expense charged to us was as follows (in millions):
		Year Ended December 31,
		2012		2011		2010
	Stock-based compensation expense	$	2	$	3	$	2

Employee_Benefit_Plans_Tables

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2012
Employee Benefit Expense [Abstract]
Allocation of Benefit Costs, Valero's Defined Benefit Plans	For our allocation of benefit costs, we recorded expense as follows (in millions):
		Year Ended December 31,
		2012		2011		2010
	Valero Savings Plan	$	7	$	5	$	6
	Valero Energy Corporation Thrift Plan	1		1		1
	Ultramar Ltd. Savings Plan	3		3		3
	For our allocation of benefit costs, we recorded expense as follows (in millions):
		Year Ended December 31,
		2012		2011		2010
	U.S. pension cost	$	2	$	1	$	1
	Canadian pension cost	2		2		2
	U.S. postretirement benefit cost	—		—		—
Allocation of Benefit Costs, Ultramar Ltd. Savings Plan	For our allocation of benefit costs, we recorded expense as follows (in millions):
		Year Ended December 31,
		2012		2011		2010
	Valero Savings Plan	$	7	$	5	$	6
	Valero Energy Corporation Thrift Plan	1		1		1
	Ultramar Ltd. Savings Plan	3		3		3
	For our allocation of benefit costs, we recorded expense as follows (in millions):
		Year Ended December 31,
		2012		2011		2010
	U.S. pension cost	$	2	$	1	$	1
	Canadian pension cost	2		2		2
	U.S. postretirement benefit cost	—		—		—

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	Income before income tax expense from our U.S. and Canadian operations was as follows (in millions):
		Year Ended December 31,
		2012			2011			2010
	U.S. operations	$	202		$	160		$	157
	Canadian operations	113			157			133
	Income before income tax expense	$	315		$	317		$	290
Schedule of Federal Income Tax	The following is a reconciliation of income tax expense to income taxes computed by applying the U.S. statutory federal income tax rate (35% for all years presented) to income before income tax expense (in millions):
		Year Ended December 31,
		2012			2011			2010
	Federal income tax expense	$	110		$	111		$	101
	at the U.S. statutory rate
	U.S. state income tax expense,	4			4			4
	net of U.S. federal income tax effect
	Canadian operations	(9		)	(11		)	(7		)
	Credits	—			(1		)	(1		)
	Income tax expense	$	105		$	103		$	97
Schedule of Components of Income Tax Expense (Benefit)	Components of income tax expense related to net income were as follows (in millions):
		Year Ended December 31,
		2012			2011			2010
	Current:
	U.S. federal	$	67		$	40		$	44
	U.S. state	6			5			4
	Canada	33			46			43
	Total current	106			91			91
	Deferred:
	U.S. federal	1			14			8
	U.S. state	—			1			1
	Canada	(2		)	(3		)	(3		)
	Total deferred	(1		)	12			6
	Income tax expense	$	105		$	103		$	97
Schedule of Deferred Tax Assets and Liabilities	The tax effects of significant temporary differences representing deferred income tax assets and liabilities were as follows (in millions):
		December 31,
		2012			2011
	Deferred income tax assets:
	Tax credit carryforwards	$	8		$	8
	Net operating losses (“NOLs”)	1			1
	Environmental liabilities	1			1
	Inventories	10			10
	Other assets	16			17
	Total deferred income tax assets	36			37
	Less: Valuation allowance	(1		)	(1		)
	Net deferred income tax assets	35			36
	Deferred income tax liabilities:
	Property and equipment	(145		)	(147		)
	Other	—			(1		)
	Total deferred income tax liabilities	(145		)	(148		)
	Net deferred income tax liabilities	$	(110	)	$	(112	)
Summary of Tax Credit Carryforwards	We had the following income tax credit and loss carryforwards as of December 31, 2012 (in millions):
		Amount			Expiration
	U.S. state income tax credits	$	12		2026
	U.S. state NOL (gross amount)	16			2018

Debt_Tables

Debt (Tables)	6 Months Ended
	Jun. 30, 2013
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	Our balances for long-term debt and capital leases are as follows (in millions):
			June 30,			December 31,
			2013			2012
	5.00% senior notes due 2023		$	550		$	—
	Term loan due 2018 (effective rate of 1.95% at June 30, 2013)		500			—
	Capital leases		4			5
	Total debt outstanding		1,054			5
	Less current portion		(29		)	(1		)
	Debt, less current portion		$	1,025		$	4
	Availability under revolving credit facility (expires 2018):
	Total available credit facility limit		$	300		$	—
	Letters of credit outstanding		(3		)	—
	Maximum leverage ratio constraint (a)		(99		)	—
	Total available and undrawn		$	198		$	—
	(a)	Our credit facility contains a maximum lease adjusted leverage ratio of 3.75 to 1.00. As a result, we were limited to the amount we could borrow under our revolving credit facility at June 30, 2013.
Schedule of Maturities of Long-term Debt	We are required to make principal payments on the term loan in accordance with an amortization schedule as follows (in millions):
	Years Ending December 31,		Total Principal to be Repaid
	2013 (remainder)		$	12
	2014		34
	2015		47
	2016		69
	2017		75
	2018		263
	Total		$	500

Related_Party_Tables

Related Party (Tables)	6 Months Ended										12 Months Ended
	Jun. 30, 2013										Dec. 31, 2012
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The following table reflects significant transactions with Valero (in millions):										The following table reflects significant transactions with related parties (in millions):
		Three Months Ended					Six Months Ended						Year Ended December 31,
		June 30,					June 30,						2012			2011			2010
		2013			2012		2013		2012		Cost of sales		$	10,810		$	10,533		$	8,170
	Cost of sales	$	2,632		$	2,688	$	5,288	$	5,390
											Operating expenses (a)		43			36			35
	Operating expenses	4			11		14		21
											General and administrative expenses (a)		36			36			33
	General and administrative expenses	5			9		12		17
											(a)	Includes stock-based compensation and employee benefit plan expense allocations that are more fully described in Notes 10 and 11, respectively.
Reconciliation of net change in net parent company investment	The following is a reconciliation of amounts presented as “Net transfers to Valero” on the consolidated and combined statement of stockholders’ equity and “Net transfers to Valero” on the consolidated and combined statement of cash flows for the six months ended June 30, 2013 (in millions):										The following is a reconciliation of the amounts presented as “Net transfers to Parent” on our statements of changes in net investment and the amounts presented as “Net transfers to Parent” on our statements of cash flows.
	Net transfers to Valero per the consolidated and combined statement of stockholders’ equity	$	(731	)									Year Ended December 31,
	Non-cash adjustments:												2012			2011			2010
	Net transfers of assets and liabilities with Valero	353									Net transfers to Parent per statements of changes in net investment		$	(222	)	$	(151	)	$	(221	)
											Non-cash transactions:
	Net transfers to Valero per the consolidated and combined statements of cash flows	$	(378	)							Transfers of assets to Parent		3			1			1
											Net transfers of cash to Parent per statements of cash flows		$	(219	)	$	(150	)	$	(220	)

Segment_Information_Tables

Segment Information (Tables)	6 Months Ended													12 Months Ended
	Jun. 30, 2013													Dec. 31, 2012
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following table reflects activity related to our reportable segments (in millions):													The following table reflects activity related to segment operating income (in millions):
		Three Months Ended						Six Months Ended							Retail–		Retail–		Corporate			Total
		June 30,						June 30,							U.S.		Canada
		2013			2012			2013			2012			Year ended December 31, 2012:
	Operating revenues													Operating revenues from external customers	$	7,907	$	5,228	$	—		$	13,135
	Retail–U.S.	$	2,007		$	2,044		$	3,935		$	3,948
														Depreciation, amortization and accretion expense	78		37		—			115
	Retail–Canada	1,204			1,301			2,464			2,609
														Operating income (loss)	246		130		(61		)	315
	Total	$	3,211		$	3,345		$	6,399		$	6,557
														Total expenditures for long-lived assets	181		42		—			223
	Depreciation, amortization and accretion expense
	Retail–U.S.	$	21		$	20		$	42		$	38
														Year ended December 31, 2011:
	Retail–Canada	9			9			18			18			Operating revenues from external customers	7,557		5,306		—			12,863
	Total	$	30		$	29		$	60		$	56		Depreciation, amortization and accretion expense	76		37		—			113
	Operating income (loss)													Operating income (loss)	202		174		(59		)	317
	Retail–U.S.	$	68		$	132		$	86		$	139
														Total expenditures for long-lived assets	91		39		—			130
	Retail–Canada	33			46			59			73
	General and administrative expense	(20		)	(14		)	(35		)	(29		)	Year ended December 31, 2010:
	Total	$	81		$	164		$	110		$	183		Operating revenues from external customers	6,183		4,188		—			10,371
	Income before income taxes													Depreciation, amortization and accretion expense	71		34		—			105
	Operating income	$	81		$	164		$	110		$	183
														Operating income (loss)	197		149		(57		)	289
	Other income, net	1			—			2			—
														Total expenditures for long-lived assets	68		37		—			105
	Interest expense	(7		)	—			(7		)	—
	Income before income tax expense	$	75		$	164		$	105		$	183
	Capital expenditures
	Retail–U.S.	$	40		$	20		$	78		$	35
	Retail–Canada	10			9			12			11
	Total	$	50		$	29		$	90		$	46
Revenue from External Customers by Products and Services	Operating revenues for our principal products were as follows (in millions):													Operating revenues from external customers for our principal products were as follows (in millions):
		Three Months Ended						Six Months Ended							Year Ended December 31,
		June 30,						June 30,							2012		2011		2010
		2013			2012			2013			2012			Motor fuel sales (gasoline and diesel)	$	11,047	$	10,758	$	8,443
	Motor fuel sales	$	2,701		$	2,815		$	5,342		$	5,477
														Merchandise sales	1,496		1,484		1,445
	Merchandise sales	399			385			751			731
														Other	592		621		483
	Other	111			145			306			349
														Total operating revenues	$	13,135	$	12,863	$	10,371
	Total operating revenues	$	3,211		$	3,345		$	6,399		$	6,557
Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country	Long-lived assets include property and equipment, goodwill and intangible assets. Geographic information by country for long-lived assets consisted of the following (in millions):													Long-lived assets include property and equipment and intangible assets. Geographic information by country for long-lived assets consisted of the following (in millions):
		June 30,			December 31,										December 31,
		2013			2012										2012		2011
	U.S.	$	971		$	938								U.S.	$	938	$	836
	Canada	356			379									Canada	379		364
	Total long-lived assets	$	1,327		$	1,317								Total long-lived assets	$	1,317	$	1,200
Reconciliation of Assets from Segment to Consolidated	Total assets by reportable segment were as follows (in millions):
		June 30,			December 31,
		2013			2012
	Retail–U.S.	$	1,463		$	1,153
	Retail–Canada	779			555
	Corporate	65			1
	Total assets	$	2,307		$	1,709
Segment Reporting Disclosure	SEGMENT INFORMATION													SEGMENT INFORMATION
	We have two reportable segments: Retail–U.S. and Retail–Canada. The Retail–U.S. segment includes convenience stores located in the United States. The Retail–Canada segment includes convenience stores, filling stations, cardlock locations and heating oil operations located in Canada. Operating revenues from our heating oil business were less than 5% of our consolidated operating revenues for the three and six months ended June 30, 2013 and have been included within the Retail–Canada segment information.													We have two reportable segments: Retail–U.S. and Retail–Canada. The Retail–U.S. segment includes convenience stores located in the U.S. The Retail–Canada segment includes convenience stores, filling stations, cardlocks and heating oil operations. Our heating oil operations are not significant and have been included within the Retail–Canada segment information. General and administrative expenses that are not included in either of the two reportable segments are included in the corporate category.
	The reportable segments are strategic business units that experience different operating income margins due to geographic supply and demand attributes and specific country and local regulatory environments. Performance is evaluated based on operating income. There are no intersegment revenues. No single customer accounted for more than 10% of our consolidated and combined operating revenues.													The reportable segments are strategic business units that experience different operating income margins due to geographic supply and demand and country and local regulatory environments. They are managed separately as each business requires unique marketing strategies that address country-specific operating requirements. Performance is evaluated based on operating income. There are no intersegment revenues.
	The following table reflects activity related to our reportable segments (in millions):													The following table reflects activity related to segment operating income (in millions):
		Three Months Ended						Six Months Ended							Retail–		Retail–		Corporate			Total
		June 30,						June 30,							U.S.		Canada
		2013			2012			2013			2012			Year ended December 31, 2012:
	Operating revenues													Operating revenues from external customers	$	7,907	$	5,228	$	—		$	13,135
	Retail–U.S.	$	2,007		$	2,044		$	3,935		$	3,948
														Depreciation, amortization and accretion expense	78		37		—			115
	Retail–Canada	1,204			1,301			2,464			2,609
														Operating income (loss)	246		130		(61		)	315
	Total	$	3,211		$	3,345		$	6,399		$	6,557
														Total expenditures for long-lived assets	181		42		—			223
	Depreciation, amortization and accretion expense
	Retail–U.S.	$	21		$	20		$	42		$	38
														Year ended December 31, 2011:
	Retail–Canada	9			9			18			18			Operating revenues from external customers	7,557		5,306		—			12,863
	Total	$	30		$	29		$	60		$	56		Depreciation, amortization and accretion expense	76		37		—			113
	Operating income (loss)													Operating income (loss)	202		174		(59		)	317
	Retail–U.S.	$	68		$	132		$	86		$	139
														Total expenditures for long-lived assets	91		39		—			130
	Retail–Canada	33			46			59			73
	General and administrative expense	(20		)	(14		)	(35		)	(29		)	Year ended December 31, 2010:
	Total	$	81		$	164		$	110		$	183		Operating revenues from external customers	6,183		4,188		—			10,371
	Income before income taxes													Depreciation, amortization and accretion expense	71		34		—			105
	Operating income	$	81		$	164		$	110		$	183
														Operating income (loss)	197		149		(57		)	289
	Other income, net	1			—			2			—
														Total expenditures for long-lived assets	68		37		—			105
	Interest expense	(7		)	—			(7		)	—
														Operating revenues from external customers for our principal products were as follows (in millions):
	Income before income tax expense	$	75		$	164		$	105		$	183
	Capital expenditures														Year Ended December 31,
	Retail–U.S.	$	40		$	20		$	78		$	35			2012		2011		2010
														Motor fuel sales (gasoline and diesel)	$	11,047	$	10,758	$	8,443
	Retail–Canada	10			9			12			11
														Merchandise sales	1,496		1,484		1,445
	Total	$	50		$	29		$	90		$	46
														Other	592		621		483
	Operating revenues for our principal products were as follows (in millions):
														Total operating revenues	$	13,135	$	12,863	$	10,371
		Three Months Ended						Six Months Ended						Operating revenues by geographic area are shown in the table below (in millions). The geographic area is based on location of customer, and no single customer accounted for more than 10% of our combined operating revenues.
		June 30,						June 30,
		2013			2012			2013			2012
	Motor fuel sales	$	2,701		$	2,815		$	5,342		$	5,477			Year Ended December 31,
															2012		2011		2010
	Merchandise sales	399			385			751			731			U.S.	$	7,907	$	7,557	$	6,183
	Other	111			145			306			349			Canada	5,228		5,306		4,188
	Total operating revenues	$	3,211		$	3,345		$	6,399		$	6,557		Total operating revenues	$	13,135	$	12,863	$	10,371
	Other operating revenues are derived from our heating oil business as well as revenues from car wash and commissions from lottery, money orders, air/water/vacuum services, video and game rentals and access to ATMs.													Long-lived assets include property and equipment and intangible assets. Geographic information by country for long-lived assets consisted of the following (in millions):
	Long-lived assets include property and equipment, goodwill and intangible assets. Geographic information by country for long-lived assets consisted of the following (in millions):
															December 31,
		June 30,			December 31,										2012		2011
		2013			2012									U.S.	$	938	$	836
	U.S.	$	971		$	938
														Canada	379		364
	Canada	356			379
														Total long-lived assets	$	1,317	$	1,200
	Total long-lived assets	$	1,327		$	1,317
														Total assets by reportable segment were as follows (in millions):
	Total assets by reportable segment were as follows (in millions):
															December 31,
		June 30,			December 31,										2012		2011
	2013			2012									Retail–U.S.	$	1,153	$	1,132
Retail–U.S.	$	1,463		$	1,153
													Retail–Canada	555		558
Retail–Canada	779			555
													Corporate	1		1
Corporate	65			1
													Total assets	$	1,709	$	1,691
Total assets	$	2,307		$	1,709
													Total assets by reportable segment were as follows (in millions):
														December 31,
														2012		2011
													Retail–U.S.	$	1,153	$	1,132
													Retail–Canada	555		558
													Corporate	1		1
													Total assets	$	1,709	$	1,691

Supplemental_Cash_Flows_Inform1

Supplemental Cash Flows Information (Tables)	6 Months Ended							12 Months Ended
	Jun. 30, 2013							Dec. 31, 2012
Supplemental Cash Flow Elements [Abstract]
Cash Flow, Operating Capital	In order to determine net cash provided by operating activities, net income is adjusted by, among other things, changes in current assets and current liabilities as follows (in millions):							In order to determine net cash provided by operating activities, net income is adjusted by, among other things, changes in current assets and current liabilities as follows (in millions):
		Six Months Ended							Year Ended December 31,
		June 30,							2012			2011			2010
		2013			2012			Decrease (increase) in current assets:
	Increase (decrease) in current assets:							Receivables, net	$	41		$	(30	)	$	(11	)
	Receivables, net	$	(69	)	$	7
								Inventories	(5		)	(5		)	(3		)
	Inventories	3			14			Prepaid expenses and other	2			(4		)	—
	Prepaid expenses and other	(6		)	—			Increase (decrease) in current liabilities:
								Accounts payable	4			(2		)	7
	Increase (decrease) in current liabilities:
	Accounts payable	1			(1		)	Accrued expenses	(3		)	(4		)	(1		)
								Taxes other than income taxes	3			5			20
	Accounts payable to Valero	342			—
								Changes in current assets and current liabilities	$	42		$	(40	)	$	12
	Accrued expenses	4			(5		)
	Taxes other than income taxes	(67		)	7
	Income taxes payable	9			—
	Changes in current assets and current liabilities	$	217		$	22
Cash Flows Related To Interest And Income Taxes								Cash flows related to interest and income taxes were as follows (in millions):
									Year Ended December 31,
									2012			2011			2010
								Interest paid	$	1		$	1		$	1
								Income taxes paid, net	106			91			91

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Tables)	6 Months Ended											12 Months Ended
	Jun. 30, 2013											Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets and Goodwill	Goodwill and intangible assets consisted of the following (in millions):											Intangible assets, net consisted of the following (in millions):
		Gross Carrying Amount				Accumulated Amortization							Gross Carrying Amount				Accumulated Amortization
		June 30,		December 31,		June 30,			December 31,				December 31,				December 31,
		2013		2012		2013			2012				2012		2011		2012			2011
	Goodwill	$	18	$	—							Customer list	$	124	$	120	$	(85	)	$	(74	)
	Intangible assets:											Other	3		2		(1		)	(1		)
	Customer lists and other	120		127		$	(85	)	$	(86	)
												Total	$	127	$	122	$	(86	)	$	(75	)
	Total	$	138	$	127	$	(85	)	$	(86	)

Equity_Tables

Equity (Tables)	6 Months Ended
	Jun. 30, 2013
Equity [Abstract]
Schedule of Share-based Compensation, Stock Options, Activity	We granted the following stock-based awards in the second quarter of 2013 under the Plan:
		Actual Number of Awards			Weighted-Average Grant-Date Fair Value
	Stock options	228,885			$	11.78
	Restricted stock	199,283			$	29.68
Schedule of Accumulated Other Comprehensive Income (Loss)	Changes in foreign currency translation adjustment were as follows for the three and six months ended June 30, 2013 (in millions):
		Three Months Ended				Six Months Ended
		June 30,				June 30,
		2013				2013
	Balance at the beginning of the period	$	155			$	165
	Other comprehensive loss before reclassifications	(20		)		(30		)
	Amounts reclassified from other comprehensive income	—				—
	Net other comprehensive loss	(20		)		(30		)
	Balance at the end of the period	$	135			$	135

Fair_Value_Tables

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2012
Fair Value Disclosures [Abstract]
Fair Value Measurements	The table below presents the fair value (in millions) of our nonfinancial assets measured on a nonrecurring basis during the years ended December 31, 2011 and 2010, and categorized according to the fair value hierarchy of the inputs utilized by us to determine the fair values as of December 31, 2011 and 2010.
		Fair Value Measurements Using
		Quoted		Significant		Significant		Total		Total Loss
		Prices in		Other		Unobservable		Fair Value		Recognized
		Active		Observable		Inputs		as of		During the
		Markets		Inputs		(Level 3)		December 31		Year Ended
		(Level 1)		(Level 2)						December 31
	2011:00:00
	Property and equipment	$	—	$	—	$	1	$	1	$	3
	2010:00:00
	Property and equipment	—		—		2		2		5

Quarterly_Financial_Data_Unaud1

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2012
Quarterly Financial Data (Unaudited) [Abstract]
Schedule of Quarterly Financial Information	The following table summarizes quarterly financial data for the years ended December 31, 2012 and 2011 (in millions).
		2012 Quarter Ended
		31-Mar		30-Jun		30-Sep		31-Dec
	Operating revenues	$	3,212	$	3,345	$	3,382	$	3,196
	Operating income	19		164		35		97
	Net income	15		108		23		64
		2011 Quarter Ended
		31-Mar		30-Jun		30-Sep		31-Dec
	Operating revenues	$	2,962	$	3,430	$	3,353	$	3,118
	Operating income	43		120		84		70
	Net income	31		80		55		48

Guarantor_Subsidiaries_Tables

Guarantor Subsidiaries (Tables)	6 Months Ended																																12 Months Ended
	Jun. 30, 2013																																Dec. 31, 2012
Guarantor Subsidiaries [Abstract]
Schedule of Condensed Balance Sheet	COMBINING BALANCE SHEETS																																COMBINING BALANCE SHEETS
	(Unaudited, Millions of Dollars)																																(Millions of Dollars)
		30-Jun-13																																31-Dec-12
		Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Consolidated																Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Combined
	ASSETS																																ASSETS
	Current assets:																																Current assets:
	Cash	$	—			$	266			$	148			$	—			$	414														Cash	$	—			$	44			$	17			$	—			$	61
	Receivables, net	—				98				99				—				197															Receivables, net	—				41				93				—				134
	Inventories	—				119				44				—				163															Inventories	—				121				47				—				168
	Deferred income taxes	—				1				8				—				9															Deferred income taxes	—				4				9				—				13
	Prepaid expenses and other	—				7				7				—				14															Prepaid expenses and other	—				3				5				—				8
	Total current assets	—				491				306				—				797															Total current assets	—				213				171				—				384
	Property and equipment, at cost	—				1,414				478				—				1,892															Property and equipment, at cost	—				1,371				492				—				1,863
	Accumulated depreciation	—				(463		)		(155		)		—				(618		)													Accumulated depreciation	—				(435		)		(152		)		—				(587		)
	Property and equipment, net	—				951				323				—				1,274															Property and equipment, net	—				936				340				—				1,276
	Goodwill and intangible assets, net	—				20				33				—				53															Intangible assets, net	—				2				39				—				41
	Investment in subsidiaries	1,610				—				—				(1,610		)		—															Other assets, net	—				3				5				—				8
	Deferred income taxes	—				—				112				—				112															Total assets	$	—			$	1,154			$	555			$	—			$	1,709
	Other assets, net	32				33				6				—				71															LIABILITIES AND NET INVESTMENT
																																	Current liabilities:
	Total assets	$	1,642			$	1,495			$	780			$	(1,610	)		$	2,307														Current portion of capital lease obligations	$	—			$	1			$	—			$	—			$	1
	LIABILITIES AND STOCKHOLDERS’ EQUITY																																Accounts payable	—				52				43				—				95
	Current liabilities:
	Current portion of debt and capital lease obligations	$	28			$	1			$	—			$	—			$	29														Accrued expenses	—				22				18				—				40
	Accounts payable	—				48				35				—				83															Taxes other than income taxes	—				22				70				—				92
	Accounts payable to Valero	(1		)		205				138				—				342															Total current liabilities	—				97				131				—				228
	Accrued expenses	7				21				16				—				44															Capital lease obligations, less current portion	—				4				—				—				4
	Taxes other than income taxes	—				20				3				—				23															Deferred income taxes	—				110				13				—				123
	Income taxes payable	—				5				4				—				9															Other long-term liabilities	—				77				30				—				107
	Total current liabilities	34				300				196				—				530															Commitments and contingencies
	Debt and capital lease obligations, less current portion	1,022				3				—				—				1,025															Net investment:
																																	Net parent investment	—				866				216				—				1,082
	Deferred income taxes	—				89				—				—				89
																																	Accumulated other comprehensive income (AOCI)	—				—				165				—				165
	Intercompany payables (receivables)	20				(20		)		—				—				—
																																	Total net investment	—				866				381				—				1,247
	Other long-term liabilities	15				68				29				—				112
																																	Total liabilities and net investment	$	—			$	1,154			$	555			$	—			$	1,709
	Commitments and contingencies
	Stockholders’ equity:
	Common stock	1				—				—				—				1															COMBINING BALANCE SHEETS (CONTINUED)
																																	(Millions of Dollars)
	Additional paid-in capital (APIC)	395				1,038				544				(1,582		)		395
	Retained earnings	20				17				11				(28		)		20																	31-Dec-11
																																			Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
	Accumulated other comprehensive income (AOCI)	135				—				—				—				135															ASSETS
																																	Current assets:
	Total stockholders’ equity	551				1,055				555				(1,610		)		551															Cash		$	116			$	16			$	132
	Total liabilities and stockholders’ equity	$	1,642			$	1,495			$	780			$	(1,610	)		$	2,307														Receivables, net		64				108				172
	COMBINING BALANCE SHEETS (CONTINUED)																																Inventories		109				50				159
	(Millions of Dollars)
																																	Deferred income taxes		3				9				12
		31-Dec-12																															Prepaid expenses and other		5				5				10
		Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Combined
	ASSETS																																Total current assets		297				188				485
	Current assets:
	Cash	$	—			$	44			$	17			$	—			$	61														Property and equipment, at cost		1,224				454				1,678
	Receivables, net	—				41				93				—				134															Accumulated depreciation		(390		)		(135		)		(525		)
																																	Property and equipment, net		834				319				1,153
	Inventories	—				121				47				—				168
																																	Intangible assets, net		2				45				47
	Deferred income taxes	—				4				9				—				13
																																	Other assets, net		1				5				6
	Prepaid expenses and other	—				3				5				—				8
																																Total assets		$	1,134			$	557			$	1,691
Total current assets	—				213				171				—				384
																																LIABILITIES AND NET INVESTMENT
Property and equipment, at cost	—				1,371				492				—				1,863															Current liabilities:
																																Current portion of capital lease obligations		$	1			$	—			$	1
Accumulated depreciation	—				(435		)		(152		)		—				(587		)
																																Accounts payable		46				38				84
Property and equipment, net	—				936				340				—				1,276
																																Accrued expenses		18				23				41
Intangible assets, net	—				2				39				—				41
																																Taxes other than income taxes		19				67				86
Other assets, net	—				3				5				—				8
																																Total current liabilities		84				128				212
Total assets	$	—			$	1,154			$	555			$	—			$	1,709
																																Capital lease obligations, less current portion		5				—				5
LIABILITIES AND NET INVESTMENT
Current liabilities:																																Deferred income taxes		109				15				124
Current portion of capital lease obligations	$	—			$	1			$	—			$	—			$	1
																																Other long-term liabilities		75				26				101
Accounts payable	—				52				43				—				95
																																Commitments and contingencies
Accrued expenses	—				22				18				—				40															Net investment:
																																Net parent investment		861				233				1,094
Taxes other than income taxes	—				22				70				—				92
																																Accumulated other comprehensive income (AOCI)		—				155				155
Income taxes payable	—				—				—				—				—
																																Total net investment		861				388				1,249
Total current liabilities	—				97				131				—				228
																																Total liabilities and net investment		$	1,134			$	557			$	1,691
Capital lease obligations, less current portion	—				4				—				—				4
Deferred income taxes	—				110				13				—				123
Other long-term liabilities	—				77				30				—				107
Commitments and contingencies
Net investment:
Net parent investment	—				866				216				—				1,082
Accumulated other comprehensive income (AOCI)	—				—				165				—				165
Total net investment	—				866				381				—				1,247
Total liabilities and net investment	$	—			$	1,154			$	555			$	—			$	1,709
Schedule of Condensed Income Statement	COMBINING STATEMENTS OF INCOME																																COMBINING STATEMENTS OF INCOME
	(Unaudited, Millions of Dollars)																																(Millions of Dollars)
		Six Months Ended June 30, 2013																																Year Ended December 31, 2012
		Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Consolidated and Combined																Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Combined
	Operating revenues	$	—			$	3,935			$	2,464			$	—			$	6,399														Operating revenues	$	—			$	7,907			$	5,228			$	—			$	13,135
	Costs and expenses:																																Costs and expenses:
	Cost of sales	—				3,608				2,266				—				5,874															Cost of sales	—				7,185				4,815				—				12,000
	Operating expenses	—				200				120				—				320															Operating expenses	—				398				246				—				644
	General and administrative expenses	1				26				8				—				35															General and administrative expenses	—				44				17				—				61
	Depreciation, amortization and accretion expense	—				42				18				—				60															Depreciation, amortization and accretion expense	—				78				37				—				115
	Total costs and expenses	1				3,876				2,412				—				6,289															Total costs and expenses	—				7,705				5,115				—				12,820
	Operating income	(1		)		59				52				—				110															Operating income	—				202				113				—				315
	Other income, net	—				—				2				—				2															Other income, net	—				—				1				—				1
	Interest expense	(7		)		—				—				—				(7		)													Interest expense	—				(1		)		—				—				(1		)
	Equity in earnings of subsidiaries	28				—				—				(28		)		—															Income before income tax expense	—				201				114				—				315
	Income before income tax expense	20				59				54				(28		)		105															Income tax expense	—				74				31				—				105
	Income tax expense	—				25				16				—				41															Net income	$	—			$	127			$	83			$	—			$	210
	Net income	$	20			$	34			$	38			$	(28	)		$	64
																																			Year Ended December 31, 2011
																																			Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
		Six Months Ended June 30, 2012																															Operating revenues		$	7,557			$	5,306			$	12,863
			Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
	Operating revenues		$	3,948			$	2,609			$	6,557																					Costs and expenses:
																																	Cost of sales		6,893				4,842				11,735
	Costs and expenses:
	Cost of sales		3,577				2,396				5,973																						Operating expenses		383				253				636
	Operating expenses		194				122				316																						General and administrative expenses		42				17				59
	General and administrative expenses		21				8				29																						Depreciation, amortization and accretion expense		76				37				113
	Depreciation, amortization and accretion expense		38				18				56																						Asset impairment losses		2				1				3
	Total costs and expenses		3,830				2,544				6,374																						Total costs and expenses		7,396				5,150				12,546
	Operating income		118				65				183																						Operating income		161				156				317
	Other income, net		—				—				—																						Other income, net		—				1				1
	Interest expense		—				—				—																						Interest expense		(1		)		—				(1		)
	Income before income tax expense		118				65				183																						Income before income tax expense		160				157				317
	Income tax expense		43				18				61																						Income tax expense		59				44				103
	Net income		$	75			$	47			$	122																					Net income		$	101			$	113			$	214
																																	COMBINING STATEMENTS OF INCOME (CONTINUED)
																																	(Millions of Dollars)
																																			Year Ended December 31, 2010
																																			Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
																																	Operating revenues		$	6,183			$	4,188			$	10,371
																																	Costs and expenses:
																																	Cost of sales		5,540				3,770				9,310
																																	Operating expenses		372				233				605
																																	General and administrative expenses		40				17				57
																																	Depreciation, amortization and accretion expense		72				33				105
																																	Asset impairment losses		2				3				5
																																	Total costs and expenses		6,026				4,056				10,082
																																	Operating income		157				132				289
																																	Other income, net		1				1				2
																																	Interest expense		(1		)		—				(1		)
																																	Income before income tax expense		157				133				290
																																	Income tax expense		57				40				97
																																	Net income		$	100			$	93			$	193
Schedule of Comprehensive Income (Loss)	COMBINING STATEMENTS OF COMPREHENSIVE INCOME
	(Unaudited, Millions of Dollars)
																																		Year Ended December 31, 2012
																																		Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Combined
		Six Months Ended June 30, 2013																															Net income	$	—			$	127			$	83			$	—			$	210
		Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Consolidated and Combined
	Net income	$	20			$	34			$	38			$	(28	)		$	64														Other comprehensive income (loss):
																																	Foreign currency translation adjustment	—				—				10				—				10
	Other comprehensive income (loss):
	Foreign currency translation adjustment	(30		)		—				—				—				(30		)													Other comprehensive income (loss) before income taxes	—				—				10				—				10
	Other comprehensive income (loss) before income taxes	(30		)		—				—				—				(30		)													Income taxes related to items of other comprehensive income	—				—				—				—				—
	Income taxes related to items of other comprehensive income	—				—				—				—				—															Other comprehensive income (loss)	—				—				10				—				10
	Other comprehensive income (loss)	(30		)		—				—				—				(30		)													Comprehensive income	$	—			$	127			$	93			$	—			$	220
	Comprehensive income	$	(10	)		$	34			$	38			$	(28	)		$	34
																																			Year Ended December 31, 2011
																																			Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
		Six Months Ended June 30, 2012																															Net income		$	101			$	113			$	214
			Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
	Net income		$	75			$	47			$	122																					Other comprehensive income (loss):
																																	Foreign currency translation adjustment		—				(7		)		(7		)
	Other comprehensive income (loss):
	Foreign currency translation adjustment		—				1				1																						Other comprehensive income (loss) before income taxes		—				(7		)		(7		)
	Other comprehensive income (loss) before income taxes		—				1				1																						Income taxes related to items of other comprehensive income		—				—				—
	Income taxes related to items of other comprehensive income		—				—				—																						Other comprehensive income (loss)		—				(7		)		(7		)
	Other comprehensive income (loss)		—				1				1																						Comprehensive income		$	101			$	106			$	207
	Comprehensive income		$	75			$	48			$	123
																																			Year Ended December 31, 2010
																																			Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
																																	Net income		$	100			$	93			$	193
																																	Other comprehensive income (loss):
																																	Foreign currency translation adjustment		—				24				24
																																	Other comprehensive income (loss) before income taxes		—				24				24
																																	Income taxes related to items of other comprehensive income		—				—				—
																																	Other comprehensive income (loss)		—				24				24
																																	Comprehensive income		$	100			$	117			$	217
Schedule of Condensed Cash Flow Statement	COMBINING STATEMENTS OF CASH FLOWS
	(Unaudited, Millions of Dollars)
																																		Year Ended December 31, 2012
																																		Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Combined
		Six Months Ended June 30, 2013																															Cash flows from operating activities:
		Parent Company				Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Eliminations				Consolidated and Combined															Net income	$	—			$	127			$	83			$	—			$	210
	Cash flows from operating activities:
	Net income	$	20			$	34			$	38			$	(28	)		$	64														Adjustments to reconcile net income to net cash provided by operating activities:
																																	Depreciation, amortization and accretion expense	—				78				37				—				115
	Adjustments to reconcile net income to net cash provided by (used in) operating activities:
	Stock-based compensation expense	—				2				—				—				$	2														Deferred income tax expense (benefit)	—				1				(2		)		—				(1		)
	Depreciation, amortization and accretion expense	—				42				18				—				60															Changes in current assets and current liabilities	—				20				22				—				42
	Deferred income tax expense	—				5				3				—				8															Other operating activities, net	—				(2		)		—				—				(2		)
	Changes in current assets and current liabilities	6				149				62				—				217															Net cash provided by operating activities	—				224				140				—				364
	Equity in earnings of subsidiaries	(28		)		—				—				28				—															Cash flows from investing activities:
																																	Capital expenditures	—				(114		)		(42		)		—				(156		)
	Other operating activities, net	—				—				—				—				—
																																	Acquisition	—				(61		)		—				—				(61		)
	Net cash provided by (used in) operating activities	(2		)		232				121				—				351
																																	Proceeds from dispositions of property and equipment	—				2				—				—				2
	Cash flows from investing activities:
	Capital expenditures	—				(78		)		(12		)		—				(90		)													Other investing activities, net	—				—				—				—				—
	Acquisition	—				—				(4		)		—				(4		)													Net cash used in investing activities	—				(173		)		(42		)		—				(215		)
	Proceeds from dispositions of property and equipment	—				—				—				—				—															Cash flows from financing activities:
																																	Payments of capital lease obligations	—				(1		)		—				—				(1		)
	Other investing activities, net	—				(1		)		(1		)		—				(2		)
																																	Net transfers to Parent	—				(122		)		(97		)		—				(219		)
	Net cash used in investing activities	—				(79		)		(17		)		—				(96		)
																																	Net cash used in financing activities	—				(123		)		(97		)		—				(220		)
	Cash flows from financing activities:
	Proceeds from issuance of long-term debt	500				—				—				—				500															Effect of foreign exchange rate changes on cash	—				—				—				—				—
	Debt issuance and credit facility origination costs	(18		)		—				—				—				(18		)													Net increase (decrease) in cash	—				(72		)		1				—				(71		)
	Intercompany funding	20				(20		)		—				—				—															Cash at beginning of year	—				116				16				—				132
	Payments of capital lease obligations	—				(1		)		—				—				(1		)													Cash at end of year	$	—			$	44			$	17			$	—			$	61
	Net transfers to Valero	(500		)		90				32				—				(378		)
	Net cash provided by financing activities	2				69				32				—				103															COMBINING STATEMENTS OF CASH FLOWS (CONTINUED)
																																	(Millions of Dollars)
	Effect of foreign exchange rate changes on cash	—				—				(5		)		—				(5		)
	Net increase in cash	—				222				131				—				353																	Year Ended December 31, 2011
																																			Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
	Cash at beginning of year	—				44				17				—				61															Cash flows from operating activities:
																																	Net income		$	101			$	113			$	214
	Cash at end of period	$	—			$	266			$	148			$	—			$	414
																																	Adjustments to reconcile net income to net cash provided
	COMBINING STATEMENTS OF CASH FLOWS (CONTINUED)																																by operating activities:
	(Unaudited, Millions of Dollars)																																Depreciation, amortization and accretion expense		76				37				113
																																	Asset impairment losses		2				1				3
		Six Months Ended June 30, 2012
			Guarantor Subsidiaries				Non-Guarantor Subsidiaries					Combined																					Non-cash interest expense		1				—				1
	Cash flows from operating activities:
	Net income		$	75			$	47				$	122																				Deferred income tax expense (benefit)		14				(2		)		12
	Adjustments to reconcile net income to net cash provided by operating activities:																																Changes in current assets and current liabilities		(35		)		(5		)		(40		)
	Stock-based compensation expense		1				—					$	1																				Other operating activities, net		5				—				5
	Depreciation, amortization and accretion expense		38				18					56																					Net cash provided by operating activities		164				144				308
	Deferred income tax expense (benefit)		(5		)		1			—		(4		)																			Cash flows from investing activities:
																																	Capital expenditures		(91		)		(39		)		(130		)
	Changes in current assets and current liabilities		(3		)		25					22																					Proceeds from dispositions of property and equipment		3				2				5
	Other operating activities, net		3				—					3																					Other investing activities, net		(1		)		(1		)		(2		)
																																	Net cash used in investing activities		(89		)		(38		)		(127		)
	Net cash provided by operating activities		109				91					200																					Cash flows from financing activities:
																																	Payments of capital lease obligations		(1		)		—				(1		)
	Cash flows from investing activities:
	Capital expenditures		(35		)		(11		)			(46		)																			Net transfers to Parent		(47		)		(103		)		(150		)
	Acquisitions		(61		)		—					(61		)																			Net cash used in financing activities		(48		)		(103		)		(151		)
																																Effect of foreign exchange rate changes on cash		—				—				—
Proceeds from dispositions of property and equipment		1				1					2
																																Net increase in cash		27				3				30
Other investing activities, net		—				—					—
																																Cash at beginning of year		89				13				102
Net cash used in investing activities		(95		)		(10		)			(105		)
Cash flows from financing activities:																																Cash at end of year		$	116			$	16			$	132
Payments of capital lease obligations		—				—					—
Net transfers to Parent		(89		)		(83		)			(172		)
Net cash used in financing activities		(89		)		(83		)			(172		)
Effect of foreign exchange rate changes on cash		—				(1		)			(1		)
Net decrease in cash		(75		)		(3		)			(78		)																			COMBINING STATEMENTS OF CASH FLOWS (CONTINUED)
Cash at beginning of year		116				16					132																					(Millions of Dollars)
Cash at end of period		$	41			$	13				$	54
																																		Year Ended December 31, 2010
																																		Guarantor Subsidiaries				Non-Guarantor Subsidiaries				Combined
																																Cash flows from operating activities:
																																Net income		$	100			$	93			$	193
																																Adjustments to reconcile net income to net cash provided
																																by operating activities:
																																Depreciation, amortization and accretion expense		72				33				105
																																Asset impairment losses		2				3				5
																																Deferred income tax expense (benefit)		9				(3		)		6
																																Changes in current assets and current liabilities		(6		)		18				12
																																Other operating activities, net		1				1				2
																																Net cash provided by operating activities		178				145				323
																																Cash flows from investing activities:
																																Capital expenditures		(68		)		(37		)		(105		)
																																Proceeds from dispositions of property and equipment		2				1				3
																																Other investing activities, net		(1		)		(1		)		(2		)
																																Net cash used in investing activities		(67		)		(37		)		(104		)
																																Cash flows from financing activities:
																																Payments of capital lease obligations		(1		)		—				(1		)
																																Net transfers to Parent		(116		)		(104		)		(220		)
																																Net cash used in financing activities		(117		)		(104		)		(221		)
																																Effect of foreign exchange rate changes on cash		—				1				1
																																Net increase (decrease) in cash		(6		)		5				(1		)
																																Cash at beginning of year		95				8				103
																																Cash at end of year		$	89			$	13			$	102
Schedule of Net Investment	COMBINING STATEMENT OF CHANGES IN EQUITY
	(Unaudited, Millions of Dollars)
																																		Accumulated Other Comprehensive Income										Net Parent Investment									Net Investment
																																		Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Combined				Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Combined			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Combined
			Common Stock																APIC														Balance as of December 31, 2009	$	—		$	138		$	138			$	823		$	236		$	1,059		$	823		$	374		$	1,197
			Parent Company			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated				Parent Company			Guarantor Subsidiaries		Non-Guarantor Subsidiaries			Eliminations			Consolidated
	Balance as of December 31, 2012		$	—		$	—		$	—		$	—		$	—			$	—		$	—	$	—		$	—		$	—		Net income	—			—			—				100			93			193			100			93			193
	Net income		—			—			—			—			—				—			—		—			—			—			Net transfers to Parent	—			—			—				(116		)	(105		)	(221		)	(116		)	(105		)	(221		)
	Net transfers to Valero		—			—			—			—			—				—			—		—			—			—			Other comprehensive income	—			24			24				—			—			—			—			24			24
	Issuance of stock at the separation and distribution		1			—			—			—			1				(1		)			—			—			(1		)	Balance as of December 31, 2010	—			162			162				807			224			1,031			807			386			1,193
	Reclassification of net parent investment to APIC		—			—			—			—			—				395			1,038		544			(1,582		)	395			Net income	—			—			—				101			113			214			101			113			214
	Stock-based compensation expense		—			—			—			—			—				1					—			—			1			Net transfers to Parent	—			—			—				(47		)	(104		)	(151		)	(47		)	(104		)	(151		)
	Other comprehensive loss		—			—			—			—			—				—			—		—			—			—			Other comprehensive income	—			(7		)	(7		)		—			—			—			—			(7		)	(7		)
	Balance as of June 30, 2013		$	1		$	—		$	—		$	—		$	1			$	395		$	1,038	$	544		$	(1,582	)	$	395		Balance as of December 31, 2011	—			155			155				861			233			1,094			861			388			1,249
																																	Net income	—			—			—				127			83			210			127			83			210
			Net Parent Investment																Retained Earnings
			Parent Company			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated				Parent Company			Guarantor Subsidiaries		Non-Guarantor Subsidiaries			Eliminations			Consolidated			Net transfers to Parent	—			—			—				(122		)	(100		)	(222		)	(122		)	(100		)	(222		)
	Balance as of December 31, 2012		$	—		$	866		$	216		$	—		$	1,082			$	—		$	—	$	—		$	—		$	—
																																	Other comprehensive income	—			10			10				—			—			—			—			10			10
	Net income		—			17			27			—			44				20			17		11			(28		)	20
																																	Balance as of December 31, 2012	$	—		$	165		$	165			$	866		$	216		$	1,082		$	866		$	381		$	1,247
	Net transfers to Valero		395			155			301			(1,582		)	(731		)		—			—		—			—			—
	Issuance of stock at the separation and distribution		—			—			—			—			—				—			—		—			—			—
	Reclassification of net parent investment to APIC		(395		)	(1,038		)	(544		)	1,582			(395		)		—			—		—			—			—
	Stock-based compensation expense		—			—			—			—			—															—
	Other comprehensive loss		—			—			—			—			—							—		—						—
	Balance as of June 30, 2013		$	—		$	—		$	—		$	—		$	—			$	20		$	17	$	11		$	(28	)	$	20
			AOCI																Total
			Parent Company			Guarantor Subsidiaries			Non-Guarantor Subsidiaries			Eliminations			Consolidated				Parent Company			Guarantor Subsidiaries		Non-Guarantor Subsidiaries			Eliminations			Consolidated
	Balance as of December 31, 2012		$	—		$	—		$	165		$	—		$	165			$	—		$	866	$	381		$	—		$	1,247
	Net income		—			—			—			—			—				$	20		$	34	$	38		$	(28	)	$	64
	Net transfers to Valero		—			—			—			—			—				$	395		$	155	$	301		$	(1,582	)	$	(731	)
	Issuance of stock at the separation and distribution		—			—			—			—			—				$	—		$	—	$	—		$	—		$	—
	Reclassification of net parent investment to APIC		165			—			(165		)	—			—				$	165		$	—	$	(165	)	$	—		$	—
	Stock-based compensation expense		—			—			—			—			—				$	1		$	—	$	—		$	—		$	1
	Other comprehensive loss		(30		)	—			—			—			(30		)		$	(30	)	$	—	$	—		$	—		$	(30	)
	Balance as of June 30, 2013		$	135		$	—		$	—		$	—		$	135			$	551		$	1,055	$	555		$	(1,610	)	$	551

The_Separation_and_the_Distrib2

The Separation and the Distribution, Basis of Presentation Description of Business and Summary of Significant Accounting Policies - Narrative (Details) (USD $)	3 Months Ended		12 Months Ended
	Jun. 30, 2013	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	1-May-13	Jun. 30, 2013	1-May-13	Nov. 30, 2012	Jun. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
							Senior Subordinated Notes	Retail - Canada	Valero Energy Corporation	Line of Credit	Revolving Credit Facility	Revolving Credit Facility
Cost of sales vendor allowances accrued rebates		$62,000,000	$70,000,000		$63,000,000
Separation and Distribution
Spinoff transaction, ownership percentage by parent company stockholders			80.00%			80.00%
Equity method investment, ownership percentage						20.00%
Long-term debt	1,050,000,000
Notes payable			0				550,000,000
Line of credit facility, maximum borrowing capacity	800,000,000									500,000,000	300,000,000	0
Letters of credit outstanding, amount											-3,000,000	0
Goodwill	18,000,000
Deferred tax assets, net								115,000,000
Deferred state and local income tax expense (benefit)	7,000,000		0	1,000,000	1,000,000
Basis of Presentation
Common stock shares issued	75,397,241								1,000
Common stock, par or stated value per share	$0.01								$0.01
Common stock, value issued	$1,000,000		$0						$10

Acquisitions_Narrative_Details

Acquisitions - Narrative (Details) (USD $)	6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Business Combinations [Abstract]
Purchase price of acquired entity	$61		$61
Goodwill	18
Payments to acquire sites	$4	$61	$61	$0	$0

Acquisitions_Purchase_Price_Al

Acquisitions - Purchase Price Allocation of Crackerbox Acquisition (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Acquisitions [Abstract]
Inventories	$3	$3
Property and equipment	38	56
Other assets	2	2
Goodwill	18
Total consideration	$61	$61

Earnings_per_Common_Share_Narr

Earnings per Common Share - Narrative (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013
Common stock shares issued	75,397,241	75,397,241
Stock Options
Antidilutive securities excluded from computation of earnings per share, amount	131,622	66,174
Restricted Stock
Antidilutive securities excluded from computation of earnings per share, amount	106,760	53,676

Earnings_per_Common_Share_Deta

Earnings per Common Share (Details) (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Earnings Per Share [Abstract]
Net income attributable to stockholders	$43	$64	$23	$108	$15	$48	$55	$80	$31	$64	$122	$210	$214	$193
Weighted-average common shares outstanding (in thousands)	75,397			75,397						75,397	75,397
Total earnings per common share	$0.57			$1.43						$0.84	$1.62
Restricted stock (in thousands)	10			0						5	0
Weighted-average common shares outstanding – assuming dilution (in thousands)	75,407			75,397						75,402	75,397
Earnings per common shares - assuming dilution	$0.57			$1.43						$0.84	$1.62

Impairment_Details

Impairment (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Carrying values	$1,892	$1,863	$1,678
Less: Estimated fair values			1	2
Retail - U.S.
Carrying values			3	3
Less: Estimated fair values			1	1
Asset impairment loss			2	2
Retail - Canada
Carrying values			1	4
Less: Estimated fair values			0	1
Asset impairment loss			$1	$3

Receivables_Details

Receivables (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Receivables [Abstract]
Trade receivables		$115	$147
Other		21	27
Receivables		136	174
Allowance for doubtful accounts		2	2	2
Receivables, net	$197	$134	$172

Receivables_Allowance_for_Doub

Receivables - Allowance for Doubtful Accounts (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Receivables [Abstract]
Balance as of beginning of year	$2	$2
Increase in allowance charged to expense	0	1	1
Accounts charged against the allowance, net of recoveries	0	-1	-1
Balance as of end of year	$2	$2	$2

Inventories_Narrative_Details

Inventories - Narrative (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Inventory Disclosure [Abstract]
Excess of replacement or current costs over stated LIFO value	$55	$56	$56

Inventories_Details

Inventories (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Inventories (textual) [Abstract]
Excess of replacement or current costs over stated LIFO value	$55	$56	$56
Inventory, Net [Abstract]
Convenience store merchandise	110	111	104
Motor fuel (at LIFO)	51	56	54
Supplies	2	1	1
Inventories	$163	$168	$159

Property_and_Equipment_Narrati

Property and Equipment - Narrative (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Abstract]
Depreciation expense	$103	$101	$94
Land and certain retail sites under capital leases	9	9
Land and certain retail sites under capital leases, accumulated depreciation	$5	$4

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Property and Equipment
Land		$387	$339
Retail site buildings		476	406
Equipment		560	535
Leasehold improvements		276	254
Other		135	130
Construction in progress		29	14
Property and equipment, at cost	1,892	1,863	1,678
Accumulated depreciation	618	587	525
Property and equipment, net	$1,274	$1,276	$1,153

Accrued_Expenses_and_Other_Lon2

Accrued Expenses and Other Long-term Liabilities - Narrative (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Accrued Expenses and Other Long-Term Liabilities [Abstract]
Other increase (decrease) in environmental liabilities	$3	$2	$2
Payments for environmental liabilities	$2	$2	$2
Property, plant and equipment, useful life	20 years

Accrued_Expenses_and_Other_Lon3

Accrued Expenses and Other Long-term Liabilities (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Accrued Expenses and Other Long-Term Liabilities [Abstract]
Wage and other employee-related liabilities, current		$22	$19
Environmental liabilities, current		2	2
Self-insurance accruals, current		6	6
Asset retirement obligations, current		2	2
Other, current		8	12
Accrued expenses and other long-term liabilities, current	44	40	41
Wage and other employee-related liabilities, noncurrent		0	0
Environmental liabilities, noncurrent		3	2
Self-insurance accruals, noncurrent		11	12
Asset retirement obligations, noncurrent		77	74
Other, noncurrent		16	13
Accrued expenses and other long-term liabilities, noncurrent	$112	$107	$101

Accrued_Expenses_and_Other_Lon4

Accrued Expenses and Other Long-term Liabilities - Asset Retirement Obligation (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Asset Retirement Obligation Disclosure [Abstract]
Balance as of beginning of year	$76	$72	$70
Additions to accrual	2	2	1
Accretion expense	4	4	4
Settlements	-4	-2	-3
Foreign currency translation	1	0	0
Balance as of end of year	$79	$76	$72

Commitments_and_Contingencies_1

Commitments and Contingencies - Narrative (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Jun. 30, 2013	Dec. 31, 2011
Commitments and contingencies
Percentage of payment for final resolultion of class action	50.00%
Accrued expenses	17
Subsequent Event
Increase (decrease) in health care insurance liabilities	5
Guarantor Subsidiaries
Commitments and contingencies
Non-Guarantor Subsidiaries
Commitments and contingencies
2015 | Subsequent Event
Environmental exit costs, anticipated cost	2
2014 | Subsequent Event
Environmental exit costs, anticipated cost	2
Next Fiscal Year | Subsequent Event
Environmental exit costs, anticipated cost	$2

Commitments_and_Contingencies_2

Commitments and Contingencies - Minimum Lease Payments (Details) (USD $)	Dec. 31, 2012
In Millions, unless otherwise specified
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2013	$23
2014	18
2015	15
2016	12
2017	9
Thereafter	26
Total minimum rental payments	103
Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2013	2
2014	1
2015	1
2016	1
2017	0
Thereafter	3
Total minimum rental payments	8
Less amount representing interest	-3
Net minimum rental payments	$5

Commitments_and_Contingencies_3

Commitments and Contingencies - Commitments and Contingencies (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Commitments and Contingencies Disclosure [Abstract]
Minimum rental expense	$25	$25	$25
Contingent rental expense	23	23	23
Total rental expense	$48	$48	$48

Stockbased_Compensation_Narrat

Stock-based Compensation - Narrative (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
stock-based compensation [Abstract]
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, stock options	$2	$2

Stockbased_Compensation_Expens

Stock-based Compensation - Expense (Details) (USD $)	3 Months Ended	6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation expense	$2	$2	$1	$2	$3	$2

Employee_Benefit_Plans_Narrati

Employee Benefit Plans - Narrative (Details)	12 Months Ended
	Dec. 31, 2012
Valero Savings Plan
Defined contribution plan minimum contribution per employee offered, percent	1.00%
Defined contribution plan, employers matching contribution, annual vesting percentage	60.00%
Defined benefit plan, contributions by employer	6.00%
Defined contribution plan, employer discretionary contribution amount	3.50%
Valero Savings Plan | Maximum
Defined contribution plan, maximum annual contribution per employee, percent	30.00%
Defined contribution plan, employer discretionary contribution amount	5.00%
Valero Energy Corporation Thrift Plan
Defined contribution plan, employers matching contribution, annual vesting percentage	100.00%
Defined benefit plan, contributions by employer	6.00%
Ultramar Ltd. Savings Plan
Defined contribution plan, employers matching contribution, annual vesting percentage	50.00%
Defined benefit plan, contributions by employer	6.00%
Defined contribution plan, employer contribution, percent	9.00%
Ultramar Ltd. Savings Plan | Maximum
Defined benefit plan, contributions by employer	12.00%

Employee_Benefit_Plans_Allocat

Employee Benefit Plans - Allocation of Benefit Costs (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
U.S. postretirement benefit cost	$0	$0	$0
Retail - U.S.
Pension expense	2	1	1
Retail - Canada
Pension expense	$2	$2	$2

Employee_Benefit_Plans_Deferre

Employee Benefit Plans - Deferred Contribution Plan (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Valero Savings Plan
Defined contribution plan, allocation of benefit costs	$7	$5	$6
Valero Energy Corporation Thrift Plan
Defined contribution plan, allocation of benefit costs	1	1	1
Ultramar Ltd. Savings Plan
Defined contribution plan, allocation of benefit costs	$3	$3	$3

Income_Taxes_Narrative_Details

Income Taxes - Narrative (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Effective income tax rate	43.00%	34.00%	39.00%	33.00%
U.S. Federal Statutory Tax Rate			35.00%		35.00%
Deferred state and local income tax expense (benefit)	$7				$0	$1	$1
Effective income tax rate, change in deferred tax assets valuation allowance	10.00%			7.00%
Current income tax expense (benefit)					106	91	91
Deferred income tax expense			8	-4	-1	12	6
Deferred tax assets, valuation allowance					1	1
Income taxes paid					$1	$0	$0

Income_Taxes_Income_Before_Inc

Income Taxes - Income Before Income Tax Expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income before income tax expense	$315	$317	$290
Retail - U.S.
Income before income tax expense	202	160	157
Retail - Canada
Income before income tax expense	$113	$157	$133

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of Net Income Expense (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Federal income tax expense at the U.S. statutory rate					$110	$111	$101
U.S. state income tax expense, net of U.S. federal income tax effect					4	4	4
Canadian operations					-9	-11	-7
Credits					0	1	1
Income tax expense	$32	$56	$41	$61	$105	$103	$97

Income_Taxes_Income_Tax_Expens

Income Taxes - Income Tax Expense Related to Net Income (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current:
U.S. federal					$67	$40	$44
U.S. state					6	5	4
Canada					33	46	43
Total current					106	91	91
Deferred:
U.S. federal					1	14	8
U.S. state	7				0	1	1
Canada					-2	-3	-3
Total deferred			8	-4	-1	12	6
Income tax expense	$32	$56	$41	$61	$105	$103	$97

Income_Taxes_Deferred_Income_T

Income Taxes - Deferred Income Tax Assets and Liabilities (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Deferred income tax assets:
Tax credit carryforwards	$8	$8
Net operating losses (“NOLs”)	1	1
Environmental liabilities	1	1
Inventories	10	10
Other assets	16	17
Total deferred income tax assets	36	37
Less: Valuation allowance	1	1
Net deferred income tax assets	35	36
Deferred income tax liabilities:
Property and equipment	145	147
Other	0	1
Total deferred income tax liabilities	145	148
Net deferred income tax liabilities	$110	$112

Income_Taxes_Tax_Credit_and_Lo

Income Taxes - Tax Credit and Loss Carry Forward (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012
Income Tax Disclosure [Abstract]
U.S. state income tax credits	$12
U.S. state income tax credits, expiration date	31-Dec-26
U.S. state NOL (gross amount)	$16
U.S. state NOL (gross amount), expiration date	2018

Debt_NarrativeDetails

Debt - Narrative(Details) (USD $)

6 Months Ended

3 Months Ended

6 Months Ended

Jun. 30, 2013

Dec. 31, 2012

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Dec. 31, 2012

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Jun. 30, 2013

Maximum

Minimum

Asset sale

Change of control

Revolving Credit Facility

Revolving Credit Facility

Line of Credit

Line of Credit

Interest Rate Margin [Member]

Alternate Base Rate [Member]

London Interbank Offered Rate (LIBOR)

Subsequent Event

Line of Credit

Line of Credit

Line of Credit

Credit Facilities (Textual)

Total lease adjusted leverage ratio

3.24

3.75

Debt issuance cost

$18,000,000

Total available credit facility limit

800,000,000

300,000,000

0

500,000,000

Term loan, due date

1-May-18

Security interests in the capital stock of domestic subsidiaries

100.00%

Security interests in the voting equity interests of foreign subsidiaries

65.00%

Security interests in the non-voting equity interests of foreign subsidiaries

100.00%

Fixed charge coverage ratio

5.56

1.3

Line of credit facility, amount outstanding

0

Term loan, margin on LIBOR

1.75%

0.75%

1.75%

Term loan, interest rate

1.95%

Notes Payable

Notes payable

0

Debt instrument, redemption price, percentage of principal amount redeemed

100.00%

101.00%

Long-term debt, fair value

1,040,000,000

Long-term debt, face amount

$1,050,000,000

Debt_Details

Debt (Details) (USD $)	Jun. 30, 2013		Dec. 31, 2012		Dec. 31, 2011
In Millions, unless otherwise specified
Debt Instrument
5.00% senior notes due 2023			$0
Term loan due 2018 (effective rate of 1.95% at June 30, 2013)			0
Capital leases	4		5
Total debt outstanding	1,054		5
Less current portion	-29		-1		-1
Debt, less current portion	1,025		4		5
Total available credit facility limit	800
Total lease adjusted leverage ratio	3.24
Revolving Credit Facility
Debt Instrument
Total available credit facility limit	300		0
Letters of credit outstanding	-3		0
Maximum leverage ratio constraint (a)	-99	[1]	0	[1]
Total available and undrawn	$198		$0
Maximum
Debt Instrument
Total lease adjusted leverage ratio	3.75
[1]	Our credit facility contains a maximum lease adjusted leverage ratio of 3.75 to 1.00. As a result, we were limited to the amount we could borrow under our revolving credit facility at June 30, 2013.

Debt_Parenthetical_Details

Debt - Parenthetical (Details)	6 Months Ended
	Jun. 30, 2013
Note payable, interest rate	5.00%
Subsequent Event
Note payable, maturity date	2023
Line of Credit | Subsequent Event
Term loan, due date	1-May-18
London Interbank Offered Rate (LIBOR) | Line of Credit
Term loan, interest rate	1.95%
Term loan, margin on LIBOR	1.75%

Debt_Principal_Payments_Due_De

Debt - Principal Payments Due (Details) (Subsequent Event, USD $)	Jun. 30, 2013
In Millions, unless otherwise specified
Subsequent Event
2013 (remainder)	$12
2014	34
2015	47
2016	69
2017	75
2018	263
Total	$500

Related_Party_Narrative_Detail

Related Party - Narrative (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cost of sales	$2,919	$2,977	$5,874	$5,973	$12,000	$11,735	$9,310
Accounts payable to Valero	342		342		0
Indemnification assets as of separation date	15		15
Change in Motor Fuel Price Formulas | Retail - U.S.
Cost of sales	2		4
Change in Motor Fuel Price Formulas | Retail - Canada
Cost of sales	$3		$6

Related_Party_Significant_Tran

Related Party - Significant Transactions with Valero (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Related Party Transactions [Abstract]
Cost of sales	$2,632	$2,688	$5,288	$5,390	$10,810	$10,533	$8,170
Operating expenses	4	11	14	21	43	36	35
General and administrative expenses	$5	$9	$12	$17	$36	$36	$33

Related_Party_Transfers_to_Val

Related Party - Transfers to Valero (Details) (USD $)	6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Related Party Transaction
Net transfers to Valero per the consolidated and combined statement of stockholders' equity	($731)		($222)	($151)	($221)
Net transfers to Valero per the consolidated and combined statement of cash flows	-378	-172	-219	-150	-220
Net Parent Investment
Related Party Transaction
Net transfers to Valero per the consolidated and combined statement of stockholders' equity	-731		-222	-151	-221
Net transfer of assts and liabilities, Related Party	$353		$3	$1	$1

Segment_Information_Narrative_

Segment Information - Narrative (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
	segments	segments
Segment Reporting [Abstract]
Number of reportable segments	2	2
Intersegment revenues	$0	$0
Major customer amounts	$0	$0

Segment_Information_Reportable

Segment Information Reportable Segments (Details) (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information
Operating revenues	$3,211	$3,196	$3,382	$3,345	$3,212	$3,118	$3,353	$3,430	$2,962	$6,399	$6,557	$13,135	$12,863	$10,371
Depreciation, amortization and accretion expense	30			29						60	56	115	113	105
Operating income	81	97	35	164	19	70	84	120	43	110	183	315	317	289
Income before income taxs												315	317	290
Other income, net	1			0						2	0	1	1	2
Interest expense	7			0						7	0	1	1	1
Income before income tax expense	75			164						105	183	315	317	290
Capital expenditures	50			29						90	46	223	130	105
Retail - U.S.
Segment Reporting Information
Operating revenues	2,007			2,044						3,935	3,948	7,907	7,557	6,183
Depreciation, amortization and accretion expense	21			20						42	38	78	76	71
Operating income	68			132						86	139	246	202	197
Income before income taxs												202	160	157
Capital expenditures	40			20						78	35	181	91	68
Retail - Canada
Segment Reporting Information
Operating revenues	1,204			1,301						2,464	2,609	5,228	5,306	4,188
Depreciation, amortization and accretion expense	9			9						18	18	37	37	34
Operating income	33			46						59	73	130	174	149
Income before income taxs												113	157	133
Capital expenditures	10			9						12	11	42	39	37
Corporate
Segment Reporting Information
Operating revenues												0	0	0
Depreciation, amortization and accretion expense												0	0	0
Operating income												-61	-59	-57
General and administrative expense	-20			-14						-35	-29
Capital expenditures												$0	$0	$0

Segment_Information_Operating_

Segment Information - Operating Revenues from External Customers (Details) (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues from External Customers and Long-Lived Assets
Operating revenues	$3,211	$3,196	$3,382	$3,345	$3,212	$3,118	$3,353	$3,430	$2,962	$6,399	$6,557	$13,135	$12,863	$10,371
Motor fuel sales
Revenues from External Customers and Long-Lived Assets
Operating revenues	2,701			2,815						5,342	5,477	11,047	10,758	8,443
Merchandise sales
Revenues from External Customers and Long-Lived Assets
Operating revenues	399			385						751	731	1,496	1,484	1,445
Other product revenues
Revenues from External Customers and Long-Lived Assets
Operating revenues	$111			$145						$306	$349	$592	$621	$483

Segment_Information_LongLived_

Segment Information - Long-Lived Assets by Reportable Segment (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Segment Reporting Information
Long-lived assets, U.S.		$1,317	$1,200
Total long-lived assets	1,327	1,317
U.S.
Segment Reporting Information
Long-lived assets, U.S.	971	938	836
Canada
Segment Reporting Information
Long-lived assets, Canada	$356	$379	$364

Segment_Information_Total_Asse

Segment Information - Total Assets by Reportable Segment (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Segment Reporting Information
Total assets	$2,307	$1,709	$1,691
Retail - U.S.
Segment Reporting Information
Total assets	1,463	1,153	1,132
Retail - Canada
Segment Reporting Information
Total assets	779	555	558
Corporate
Segment Reporting Information
Total assets	$65	$1	$1

Segment_Information_Revenue_by

Segment Information - Revenue by Product (Details) (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue from External Customer
Operating revenues	$3,211	$3,196	$3,382	$3,345	$3,212	$3,118	$3,353	$3,430	$2,962	$6,399	$6,557	$13,135	$12,863	$10,371
Motor fuel sales
Revenue from External Customer
Operating revenues	2,701			2,815						5,342	5,477	11,047	10,758	8,443
Merchandise sales
Revenue from External Customer
Operating revenues	399			385						751	731	1,496	1,484	1,445
Other product revenues
Revenue from External Customer
Operating revenues	$111			$145						$306	$349	$592	$621	$483

Segment_Information_Operating_1

Segment Information - Operating Revenues by Geographic Area (Details) (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information
Operating revenues	$3,211	$3,196	$3,382	$3,345	$3,212	$3,118	$3,353	$3,430	$2,962	$6,399	$6,557	$13,135	$12,863	$10,371
U.S.
Segment Reporting Information
Operating revenues												7,907	7,557	6,183
Canada
Segment Reporting Information
Operating revenues												$5,228	$5,306	$4,188

Supplemental_Cash_Flows_Inform2

Supplemental Cash Flows Information - Narrative (Details) (USD $)	6 Months Ended	12 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Interest paid	$1	$1	$1	$1
Income taxes paid		1	0	0
Notes payable		0
Common stock shares issued	75,397,241
Senior Subordinated Notes
Notes payable	$550

Supplemental_Cash_Flows_Inform3

Supplemental Cash Flows Information - Changes in Current Assets and Current Liabilities (Details) (USD $)	6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Receivables, net	($69)	$7	$41	($30)	($11)
Inventories	3	14	-5	-5	-3
Prepaid expenses and other	-6	0	2	-4	0
Accounts payable	1	-1	4	-2	7
Accounts payable to Valero	342	0
Accrued expenses	4	-5	-3	-4	-1
Taxes other than income taxes	-67	7	3	5	20
Income taxes payable	9	0
Changes in current assets and current liabilities	($217)	($22)	($42)	$40	($12)

Supplemental_Cash_Flows_Inform4

Supplemental Cash Flows Information - Cash Flows Related to Interest and Income Taxes (Details) (USD $)	6 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Supplemental Cash Flow Elements [Abstract]
Interest paid	$1	$1	$1	$1
Income taxes paid, net		$106	$91	$91

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets - Narrative (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$8	$8	$7
Finite-lived intangible assets, amortization expense, 2013-2016	8
Finite-lived intangible assets, amortization expense, 2017	$1

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets - Goodwill (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Nov. 30, 2012
In Millions, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$18	$0
Customer lists and other	120	127	122
Total intangible assets, gross carrying amount	138	127
Customer lists and other, accumulated amortization	$85	$86	$75

Goodwill_and_Intangible_Assets5

Goodwill and Intangible Assets - Intangible Assets (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Nov. 30, 2012
In Millions, unless otherwise specified
Customer lists and other	$120	$127	$122
Customer lists and other, accumulated amortization	85	86	75
Customer Lists
Customer lists and other		124	120
Customer lists and other, accumulated amortization		85	74
Other Intangible Assets
Customer lists and other		3	2
Customer lists and other, accumulated amortization		$1	$1

Equity_Narrative_Details

Equity - Narrative (Details) (USD $)	3 Months Ended	6 Months Ended		12 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Equity [Abstract]
Common stock, shares authorized	250,000,000	250,000,000
Common stock, par or stated value per share	$0.01	$0.01
Common stock shares issued	75,397,241	75,397,241
Common stock shares outstanding	75,397,241	75,397,241
Share-based compensation subsequent to business reorganization		$1
Share-based compensation arrangement by share-based payment award, number of shares available for grant	7,600,000	7,600,000
Stock-based compensation expense	2	2	1	2	3	2
Share-based compensation arrangements by share-based payment award, options, grants in period, weighted average exercise price	$29.77
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, stock options	2	2		2
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, period for recognition		1 year 10 months 13 days
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, share-based awards other than options	$5	$5
Share-based compensation arrangement by share-based payment award, options, outstanding, weighted average remaining contractual term		2 years 2 months 10 days

Equity_StockBased_Compensation

Equity - Stock-Based Compensation (Details) (USD $)	6 Months Ended
	Jun. 30, 2013
Stock Options
Class of Stock
Actual number of awards	228,885
Weighted-average grant-date fair value	$11.78
Restricted Stock
Class of Stock
Actual number of awards	199,283
Weighted-average grant-date fair value	$29.68

Equity_Foreign_Currency_Transl

Equity - Foreign Currency Translation Adjustment (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Equity [Abstract]
Balance at the beginning of the period	$155		$165
Other comprehensive loss before reclassifications	-20	-8	-30	1	10	-7	24
Amounts reclassified from other comprehensive income	0		0
Net other comprehensive loss	-20		-30
Balance at the end of the period	$135		$135		$165

Fair_Value_Narrative_Details

Fair Value - Narrative (Details) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]
Liabilities measured at fair value	$0	$0	$0

Fair_Value_Details

Fair Value (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Fair Value Disclosures [Abstract]
Quoted prices in active markets (Level 1)		$0	$0
Significant other observable inputs (Level 2)		0	0
Significant unobservable inputs (Level 3)		1	2
Total fair value as of December 31		1	2
Total loss recognized during the year ended December 31	$0	$3	$5

Quarterly_Financial_Data_Unaud2

Quarterly Financial Data (Unaudited) (Details) (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly Financial Data (Unaudited) [Abstract]
Operating revenues	$3,211	$3,196	$3,382	$3,345	$3,212	$3,118	$3,353	$3,430	$2,962	$6,399	$6,557	$13,135	$12,863	$10,371
Operating income	81	97	35	164	19	70	84	120	43	110	183	315	317	289
Net income	$43	$64	$23	$108	$15	$48	$55	$80	$31	$64	$122	$210	$214	$193

Guarantor_Subsidiaries_Balance

Guarantor Subsidiaries - Balance Sheets (Details) (USD $)	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current assets:
Cash	$414,000,000	$61,000,000	$54,000,000	$132,000,000	$102,000,000	$103,000,000
Receivables, net	197,000,000	134,000,000		172,000,000
Inventories	163,000,000	168,000,000		159,000,000
Deferred income taxes	9,000,000	13,000,000		12,000,000
Prepaid expenses and other	14,000,000	8,000,000		10,000,000
Total current assets	797,000,000	384,000,000		485,000,000
Property and equipment, at cost	1,892,000,000	1,863,000,000		1,678,000,000
Accumulated depreciation	618,000,000	587,000,000		525,000,000
Property and equipment, net	1,274,000,000	1,276,000,000		1,153,000,000
Goodwill and intangible assets, net	53,000,000	41,000,000		47,000,000
Investment in subsidiaries	0
Deferred income taxes	112,000,000	0
Other assets, net	71,000,000	8,000,000		6,000,000
Total assets	2,307,000,000	1,709,000,000		1,691,000,000
Current liabilities:
Current portion of debt and capital lease obligations	29,000,000	1,000,000		1,000,000
Accounts payable	83,000,000	95,000,000		84,000,000
Accounts payable to Valero	342,000,000	0
Accrued expenses	44,000,000	40,000,000		41,000,000
Taxes other than income taxes	23,000,000	92,000,000		86,000,000
Income taxes payable	9,000,000	0
Total current liabilities	530,000,000	228,000,000		212,000,000
Debt and capital lease obligations, less current portion	1,025,000,000	4,000,000		5,000,000
Deferred income taxes	89,000,000	123,000,000		124,000,000
Intercompany payables (receivables)	0
Other long-term liabilities	112,000,000	107,000,000		101,000,000
Commitments and contingencies
Stockholders’ equity / net investment:
Common stock	-1,000,000	0
Net parent investment	0	1,082,000,000		1,094,000,000
Additional paid-in capital (APIC)	395,000,000	0
Retained earnings	20,000,000	0
Accumulated other comprehensive income (AOCI)	135,000,000	165,000,000		155,000,000
Total stockholders' equity	551,000,000	1,247,000,000		1,249,000,000	1,193,000,000	1,197,000,000
Total net investment		1,247,000,000		1,249,000,000
Total liabilities and stockholders’ equity / net investment	2,307,000,000	1,709,000,000		1,691,000,000
Parent Company
Current assets:
Cash	0	0		0
Receivables, net	0	0
Inventories	0	0
Deferred income taxes	0	0
Prepaid expenses and other	0	0
Total current assets	0	0
Property and equipment, at cost	0	0
Accumulated depreciation	0	0
Property and equipment, net	0	0
Goodwill and intangible assets, net	0	0
Investment in subsidiaries	1,610,000,000
Deferred income taxes	0
Other assets, net	32,000,000	0
Total assets	1,642,000,000	0
Current liabilities:
Current portion of debt and capital lease obligations	28,000,000	0
Accounts payable	0	0
Accounts payable to Valero	-1,000,000
Accrued expenses	7,000,000	0
Taxes other than income taxes	0	0
Income taxes payable	0	0
Total current liabilities	34,000,000	0
Debt and capital lease obligations, less current portion	1,022,000,000	0
Deferred income taxes	0	0
Intercompany payables (receivables)	20,000,000
Other long-term liabilities	15,000,000	0
Commitments and contingencies
Stockholders’ equity / net investment:
Common stock	-1,000,000
Net parent investment		0
Additional paid-in capital (APIC)	395,000,000
Retained earnings	20,000,000
Accumulated other comprehensive income (AOCI)	135,000,000	0
Total stockholders' equity	551,000,000	0
Total net investment		0
Total liabilities and stockholders’ equity / net investment	1,642,000,000	0
Guarantor Subsidiaries
Current assets:
Cash	266,000,000	44,000,000	41,000,000	116,000,000	89,000,000	95,000,000
Receivables, net	98,000,000	41,000,000		64,000,000
Inventories	119,000,000	121,000,000		109,000,000
Deferred income taxes	1,000,000	4,000,000		3,000,000
Prepaid expenses and other	7,000,000	3,000,000		5,000,000
Total current assets	491,000,000	213,000,000		297,000,000
Property and equipment, at cost	1,414,000,000	1,371,000,000		1,224,000,000
Accumulated depreciation	463,000,000	435,000,000		390,000,000
Property and equipment, net	951,000,000	936,000,000		834,000,000
Goodwill and intangible assets, net	20,000,000	2,000,000		2,000,000
Investment in subsidiaries	0
Deferred income taxes	0
Other assets, net	33,000,000	3,000,000		1,000,000
Total assets	1,495,000,000	1,154,000,000		1,134,000,000
Current liabilities:
Current portion of debt and capital lease obligations	1,000,000	1,000,000		1,000,000
Accounts payable	48,000,000	52,000,000		46,000,000
Accounts payable to Valero	205,000,000
Accrued expenses	21,000,000	22,000,000		18,000,000
Taxes other than income taxes	20,000,000	22,000,000		19,000,000
Income taxes payable	5,000,000	0
Total current liabilities	300,000,000	97,000,000		84,000,000
Debt and capital lease obligations, less current portion	3,000,000	4,000,000		5,000,000
Deferred income taxes	89,000,000	110,000,000		109,000,000
Intercompany payables (receivables)	-20,000,000
Other long-term liabilities	68,000,000	77,000,000		75,000,000
Commitments and contingencies
Stockholders’ equity / net investment:
Common stock	0
Net parent investment		866,000,000		861,000,000
Additional paid-in capital (APIC)	1,038,000,000
Retained earnings	17,000,000
Accumulated other comprehensive income (AOCI)	0	0		0
Total stockholders' equity	1,055,000,000	866,000,000		861,000,000	807,000,000	823,000,000
Total net investment		866,000,000		861,000,000
Total liabilities and stockholders’ equity / net investment	1,495,000,000	1,154,000,000		1,134,000,000
Non-Guarantor Subsidiaries
Current assets:
Cash	148,000,000	17,000,000	13,000,000	16,000,000	13,000,000	8,000,000
Receivables, net	99,000,000	93,000,000		108,000,000
Inventories	44,000,000	47,000,000		50,000,000
Deferred income taxes	8,000,000	9,000,000		9,000,000
Prepaid expenses and other	7,000,000	5,000,000		5,000,000
Total current assets	306,000,000	171,000,000		188,000,000
Property and equipment, at cost	478,000,000	492,000,000		454,000,000
Accumulated depreciation	155,000,000	152,000,000		135,000,000
Property and equipment, net	323,000,000	340,000,000		319,000,000
Goodwill and intangible assets, net	33,000,000	39,000,000		45,000,000
Investment in subsidiaries	0
Deferred income taxes	112,000,000
Other assets, net	6,000,000	5,000,000		5,000,000
Total assets	780,000,000	555,000,000		557,000,000
Current liabilities:
Current portion of debt and capital lease obligations	0	0		0
Accounts payable	35,000,000	43,000,000		38,000,000
Accounts payable to Valero	138,000,000
Accrued expenses	16,000,000	18,000,000		23,000,000
Taxes other than income taxes	3,000,000	70,000,000		67,000,000
Income taxes payable	4,000,000	0
Total current liabilities	196,000,000	131,000,000		128,000,000
Debt and capital lease obligations, less current portion	0	0		0
Deferred income taxes	0	13,000,000		15,000,000
Intercompany payables (receivables)	0
Other long-term liabilities	29,000,000	30,000,000		26,000,000
Commitments and contingencies
Stockholders’ equity / net investment:
Common stock	0
Net parent investment		216,000,000		233,000,000
Additional paid-in capital (APIC)	544,000,000
Retained earnings	11,000,000
Accumulated other comprehensive income (AOCI)	0	165,000,000		155,000,000
Total stockholders' equity	555,000,000	381,000,000		388,000,000	386,000,000	374,000,000
Total net investment		381,000,000		388,000,000
Total liabilities and stockholders’ equity / net investment	780,000,000	555,000,000		557,000,000
Consolidation, Eliminations
Current assets:
Cash	0	0		0
Receivables, net	0	0
Inventories	0	0
Deferred income taxes	0	0
Prepaid expenses and other	0	0
Total current assets	0	0
Property and equipment, at cost	0	0
Accumulated depreciation	0	0
Property and equipment, net	0	0
Goodwill and intangible assets, net	0	0
Investment in subsidiaries	-1,610,000,000
Deferred income taxes	0
Other assets, net	0	0
Total assets	-1,610,000,000	0
Current liabilities:
Current portion of debt and capital lease obligations	0	0
Accounts payable	0	0
Accounts payable to Valero	0
Accrued expenses	0	0
Taxes other than income taxes	0	0
Income taxes payable	0	0
Total current liabilities	0	0
Debt and capital lease obligations, less current portion	0	0
Deferred income taxes	0	0
Intercompany payables (receivables)	0
Other long-term liabilities	0	0
Commitments and contingencies
Stockholders’ equity / net investment:
Common stock	0
Net parent investment		0
Additional paid-in capital (APIC)	-1,582,000,000
Retained earnings	-28,000,000
Accumulated other comprehensive income (AOCI)	0	0
Total stockholders' equity	-1,610,000,000
Total net investment		0
Total liabilities and stockholders’ equity / net investment	-1,610,000,000	0
Additional Paid-in Capital
Stockholders’ equity / net investment:
Total stockholders' equity	395,000,000	0
Additional Paid-in Capital | Parent Company
Stockholders’ equity / net investment:
Additional paid-in capital (APIC)	395,000,000
Total stockholders' equity	395,000,000	0
Additional Paid-in Capital | Guarantor Subsidiaries
Stockholders’ equity / net investment:
Additional paid-in capital (APIC)	1,038,000,000
Total stockholders' equity	1,038,000,000	0
Additional Paid-in Capital | Non-Guarantor Subsidiaries
Stockholders’ equity / net investment:
Additional paid-in capital (APIC)	544,000,000
Total stockholders' equity	544,000,000	0
Additional Paid-in Capital | Consolidation, Eliminations
Stockholders’ equity / net investment:
Additional paid-in capital (APIC)	-1,582,000,000
Total stockholders' equity	($1,582,000,000)	$0

Guarantor_Subsidiaries_Income_

Guarantor Subsidiaries - Income Statement (Details) (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating revenues	$3,211	$3,196	$3,382	$3,345	$3,212	$3,118	$3,353	$3,430	$2,962	$6,399	$6,557	$13,135	$12,863	$10,371
Costs and expenses:
Cost of sales	2,919			2,977						5,874	5,973	12,000	11,735	9,310
Operating expenses	161			161						320	316	644	636	605
General and administrative expenses	20			14						35	29	61	59	57
Depreciation, amortization and accretion expense	30			29						60	56	115	113	105
Asset impairment losses												0	3	5
Total costs and expenses	3,130			3,181						6,289	6,374	12,820	12,546	10,082
Operating income	81	97	35	164	19	70	84	120	43	110	183	315	317	289
Other income, net	1			0						2	0	1	1	2
Interest expense	7			0						7	0	1	1	1
Equity in earnings of subsidiaries										0
Income before income tax expense	75			164						105	183	315	317	290
Income tax expense	32			56						41	61	105	103	97
Net income	43	64	23	108	15	48	55	80	31	64	122	210	214	193
Parent Company
Operating revenues										0		0
Costs and expenses:
Cost of sales										0		0
Operating expenses										0		0
General and administrative expenses										1		0
Depreciation, amortization and accretion expense										0		0
Total costs and expenses										1		0
Operating income										-1		0
Other income, net										0		0
Interest expense										7		0
Equity in earnings of subsidiaries										28
Income before income tax expense										20		0
Income tax expense										0		0
Net income										20		0
Guarantor Subsidiaries
Operating revenues										3,935	3,948	7,907	7,557	6,183
Costs and expenses:
Cost of sales										3,608	3,577	7,185	6,893	5,540
Operating expenses										200	194	398	383	372
General and administrative expenses										26	21	44	42	40
Depreciation, amortization and accretion expense										42	38	78	76	72
Asset impairment losses													2	2
Total costs and expenses										3,876	3,830	7,705	7,396	6,026
Operating income										59	118	202	161	157
Other income, net										0	0	0	0	1
Interest expense										0	0	1	1	1
Equity in earnings of subsidiaries										0
Income before income tax expense										59	118	201	160	157
Income tax expense										25	43	74	59	57
Net income										34	75	127	101	100
Non-Guarantor Subsidiaries
Operating revenues										2,464	2,609	5,228	5,306	4,188
Costs and expenses:
Cost of sales										2,266	2,396	4,815	4,842	3,770
Operating expenses										120	122	246	253	233
General and administrative expenses										8	8	17	17	17
Depreciation, amortization and accretion expense										18	18	37	37	33
Asset impairment losses													1	3
Total costs and expenses										2,412	2,544	5,115	5,150	4,056
Operating income										52	65	113	156	132
Other income, net										2	0	1	1	1
Interest expense										0	0	0	0	0
Equity in earnings of subsidiaries										0
Income before income tax expense										54	65	114	157	133
Income tax expense										16	18	31	44	40
Net income										38	47	83	113	93
Consolidation, Eliminations
Operating revenues										0		0
Costs and expenses:
Cost of sales										0		0
Operating expenses										0		0
General and administrative expenses										0		0
Depreciation, amortization and accretion expense										0		0
Total costs and expenses										0		0
Operating income										0		0
Other income, net										0		0
Interest expense										0		0
Equity in earnings of subsidiaries										-28
Income before income tax expense										-28		0
Income tax expense										0		0
Net income										-28		0
Net Parent Investment
Costs and expenses:
Net income										44		210	214	193
Net Parent Investment | Guarantor Subsidiaries
Costs and expenses:
Net income										17
Net Parent Investment | Non-Guarantor Subsidiaries
Costs and expenses:
Net income										$27

Guarantor_Subsidiaries_Compreh

Guarantor Subsidiaries - Comprehensive Income (Details) (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$43	$64	$23	$108	$15	$48	$55	$80	$31	$64	$122	$210	$214	$193
Foreign currency translation adjustment	-20			-8						-30	1	10	-7	24
Other comprehensive income (loss) before income taxes	-20			-8						-30	1	10	-7	24
Income taxes related to items of other comprehensive income	0			0						0	0	0	0	0
Other comprehensive income (loss)	-20			-8						-30	1	10	-7	24
Comprehensive income	23			100						34	123	220	207	217
Parent Company
Net income										20		0
Foreign currency translation adjustment										-30		0
Other comprehensive income (loss) before income taxes										-30		0
Income taxes related to items of other comprehensive income										0		0
Other comprehensive income (loss)										-30		0
Comprehensive income										-10		0
Guarantor Subsidiaries
Net income										34	75	127	101	100
Foreign currency translation adjustment										0	0	0	0	0
Other comprehensive income (loss) before income taxes										0	0	0	0	0
Income taxes related to items of other comprehensive income										0	0	0	0	0
Other comprehensive income (loss)										0	0	0	0	0
Comprehensive income										34	75	127	101	100
Non-Guarantor Subsidiaries
Net income										38	47	83	113	93
Foreign currency translation adjustment											1
Other comprehensive income (loss) before income taxes										0	1	10	-7	24
Income taxes related to items of other comprehensive income										0	0	0	0	0
Other comprehensive income (loss)										0	1	10	-7	24
Comprehensive income										38	48	93	106	117
Consolidation, Eliminations
Net income										-28		0
Foreign currency translation adjustment										0		0
Other comprehensive income (loss) before income taxes										0		0
Income taxes related to items of other comprehensive income										0		0
Other comprehensive income (loss)										0		0
Comprehensive income										-28		0
Net Parent Investment
Net income										44		210	214	193
Other comprehensive income (loss)												0	0	0
Net Parent Investment | Guarantor Subsidiaries
Net income										17
Other comprehensive income (loss)												0	0	0
Net Parent Investment | Non-Guarantor Subsidiaries
Net income										27
Other comprehensive income (loss)												0	0	0
Accumulated Other Comprehensive Income (Loss)
Net income												0	0	0
Other comprehensive income (loss) before income taxes										-30
Other comprehensive income (loss)										-30		10	-7	24
Accumulated Other Comprehensive Income (Loss) | Parent Company
Other comprehensive income (loss)										-30
Accumulated Other Comprehensive Income (Loss) | Guarantor Subsidiaries
Net income												0	0	0
Other comprehensive income (loss)												0	0	0
Accumulated Other Comprehensive Income (Loss) | Non-Guarantor Subsidiaries
Net income												0	0	0
Foreign currency translation adjustment										0
Other comprehensive income (loss)												$10

Guarantor_Subsidiaries_Cash_Fl

Guarantor Subsidiaries - Cash Flows (Details) (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$43	$64	$23	$108	$15	$48	$55	$80	$31	$64	$122	$210	$214	$193
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense	2									2	1	2	3	2
Depreciation, amortization and accretion expense	30			29						60	56	115	113	105
Asset impairment losses												0	3	5
Non-cash interest expense												0	1	0
Deferred income tax expense										8	-4	-1	12	6
Changes in current assets and current liabilities										217	22	42	-40	12
Equity in Earnings of Subsidiaries										0
Other operating activities, net										0	3	-2	5	2
Net cash provided by operating activities										351	200	364	308	323
Cash flows from investing activities:
Capital expenditures										-90	-46	-156	-130	-105
Proceeds from dispositions of property and equipment										0	2	2	5	3
Acquisitions										-4	-61	-61	0	0
Other investing activities, net										-2	0	0	-2	-2
Net cash used in investing activities										-96	-105	-215	-127	-104
Cash flows from financing activities:
Investment in subsidiaries	0									0
Proceeds from issuance of long-term debt										500	0
Payments of capital lease obligations										-1	0	-1	-1	-1
Net transfers to Parent										-378	-172	-219	-150	-220
Debt issuance and credit facility origination costs										-18	0
Intercompany funding										0
Net transfers to Valero										-378
Net cash provided by (used in) financing activities										103	-172	-220	-151	-221
Effect of foreign exchange rate changes on cash										-5	-1	0	0	1
Net increase (decrease) in cash										353	-78	-71	30	-1
Cash at beginning of period			54		132				102	61	132	132	102	103
Cash at end of period	414	61		54		132				414	54	61	132	102
Parent Company
Net income										20		0
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense										0
Depreciation, amortization and accretion expense										0		0
Deferred income tax expense										0		0
Changes in current assets and current liabilities										6		0
Equity in Earnings of Subsidiaries										-28
Other operating activities, net										0		0
Net cash provided by operating activities										-2		0
Cash flows from investing activities:
Capital expenditures										0		0
Proceeds from dispositions of property and equipment										0		0
Acquisitions										0		0
Other investing activities, net										0		0
Net cash used in investing activities										0		0
Cash flows from financing activities:
Investment in subsidiaries	1,610									1,610
Proceeds from issuance of long-term debt										500
Payments of capital lease obligations										0		0
Net transfers to Parent												0
Debt issuance and credit facility origination costs										-18
Intercompany funding										20
Net transfers to Valero										-500
Net cash provided by (used in) financing activities										2		0
Effect of foreign exchange rate changes on cash										0		0
Net increase (decrease) in cash										0		0
Cash at beginning of period					0					0	0	0
Cash at end of period	0	0								0		0
Guarantor Subsidiaries
Net income										34	75	127	101	100
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense										2	1
Depreciation, amortization and accretion expense										42	38	78	76	72
Asset impairment losses													2	2
Non-cash interest expense													1
Deferred income tax expense										5	-5	1	14	9
Changes in current assets and current liabilities										149	-3	20	-35	-6
Equity in Earnings of Subsidiaries										0
Other operating activities, net											3	-2	5	1
Net cash provided by operating activities										232	109	224	164	178
Cash flows from investing activities:
Capital expenditures										-78	-35	-114	-91	-68
Proceeds from dispositions of property and equipment										0	1	2	3	2
Acquisitions										0	-61	-61
Other investing activities, net										-1	0	0	-1	-1
Net cash used in investing activities										-79	-95	-173	-89	-67
Cash flows from financing activities:
Investment in subsidiaries	0									0
Proceeds from issuance of long-term debt										0
Payments of capital lease obligations										-1	0	-1	-1	-1
Net transfers to Parent											-89	-122	-47	-116
Debt issuance and credit facility origination costs										0
Intercompany funding										-20
Net transfers to Valero										90
Net cash provided by (used in) financing activities										69	-89	-123	-48	-117
Effect of foreign exchange rate changes on cash										0	0	0	0	0
Net increase (decrease) in cash										222	-75	-72	27	-6
Cash at beginning of period					116				89	44	116	116	89	95
Cash at end of period	266	44		41		116				266	41	44	116	89
Non-Guarantor Subsidiaries
Net income										38	47	83	113	93
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense										0	0
Depreciation, amortization and accretion expense										18	18	37	37	33
Asset impairment losses													1	3
Non-cash interest expense													0
Deferred income tax expense										3	1	-2	-2	-3
Changes in current assets and current liabilities										62	25	22	-5	18
Equity in Earnings of Subsidiaries										0
Other operating activities, net											0	0	0	1
Net cash provided by operating activities										121	91	140	144	145
Cash flows from investing activities:
Capital expenditures										-12	-11	-42	-39	-37
Proceeds from dispositions of property and equipment										0	1	0	2	1
Acquisitions										-4	0	0
Other investing activities, net										-1	0	0	-1	-1
Net cash used in investing activities										-17	-10	-42	-38	-37
Cash flows from financing activities:
Investment in subsidiaries	0									0
Proceeds from issuance of long-term debt										0
Payments of capital lease obligations										0	0	0	0	0
Net transfers to Parent											-83	-97	-103	-104
Debt issuance and credit facility origination costs										0
Intercompany funding										0
Net transfers to Valero										32
Net cash provided by (used in) financing activities										32	-83	-97	-103	-104
Effect of foreign exchange rate changes on cash										-5	-1	0	0	1
Net increase (decrease) in cash										131	-3	1	3	5
Cash at beginning of period					16				13	17	16	16	13	8
Cash at end of period	148	17		13		16				148	13	17	16	13
Consolidation, Eliminations
Net income										-28		0
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation expense										0
Depreciation, amortization and accretion expense										0		0
Deferred income tax expense										0		0
Changes in current assets and current liabilities										0		0
Equity in Earnings of Subsidiaries										28
Other operating activities, net										0		0
Net cash provided by operating activities										0		0
Cash flows from investing activities:
Capital expenditures										0		0
Proceeds from dispositions of property and equipment										0		0
Acquisitions										0		0
Other investing activities, net										0		0
Net cash used in investing activities										0		0
Cash flows from financing activities:
Investment in subsidiaries	-1,610									-1,610
Proceeds from issuance of long-term debt										0
Payments of capital lease obligations										0		0
Net transfers to Parent												0
Debt issuance and credit facility origination costs										0
Intercompany funding										0
Net transfers to Valero										0
Net cash provided by (used in) financing activities										0		0
Effect of foreign exchange rate changes on cash										0		0
Net increase (decrease) in cash										0		0
Cash at beginning of period					0					0	0	0
Cash at end of period	0	0								0		0
Net Parent Investment
Net income										44		210	214	193
Net Parent Investment | Guarantor Subsidiaries
Net income										17
Adjustments to reconcile net income to net cash provided by operating activities:
Other operating activities, net										0
Net Parent Investment | Non-Guarantor Subsidiaries
Net income										27
Adjustments to reconcile net income to net cash provided by operating activities:
Other operating activities, net										$0

Guarantor_Subsidiaries_Net_Inv

Guarantor Subsidiaries - Net Investment (Details) (USD $)	3 Months Ended									6 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stockholders' equity					$1,249				$1,193	$1,247	$1,249	$1,249	$1,193	$1,197
Net income	43	64	23	108	15	48	55	80	31	64	122	210	214	193
Net transfers to Valero										-731		-222	-151	-221
Additional paid-in capital (APIC)	395	0								395		0
Stock-based compensation expense										1
Other comprehensive loss	-20			-8						-30	1	10	-7	24
Stockholders' equity	551	1,247				1,249				551		1,247	1,249	1,193
Parent Company
Stockholders' equity										0
Net income										20		0
Net transfers to Valero										395
Additional paid-in capital (APIC)	395									395
Adjustment to Additional Paid in Capital from Net Parent Investment										165
Stock-based compensation expense										1
Other comprehensive loss										-30		0
Stockholders' equity	551	0								551		0
Guarantor Subsidiaries
Stockholders' equity					861				807	866	861	861	807	823
Net income										34	75	127	101	100
Net transfers to Valero										155		-122	-47	-116
Additional paid-in capital (APIC)	1,038									1,038
Other comprehensive loss										0	0	0	0	0
Stockholders' equity	1,055	866				861				1,055		866	861	807
Non-Guarantor Subsidiaries
Stockholders' equity					388				386	381	388	388	386	374
Net income										38	47	83	113	93
Net transfers to Valero										301		-100	-104	-105
Additional paid-in capital (APIC)	544									544
Adjustment to Additional Paid in Capital from Net Parent Investment										-165
Other comprehensive loss										0	1	10	-7	24
Stockholders' equity	555	381				388				555		381	388	386
Intersegment Elimination [Member]
Stockholders' equity										0
Net income										-28
Net transfers to Valero										-1,582
Stockholders' equity	-1,610									-1,610
Consolidation, Eliminations
Net income										-28		0
Additional paid-in capital (APIC)	-1,582									-1,582
Other comprehensive loss										0		0
Stockholders' equity	-1,610									-1,610
Common Stock Par Value
Stockholders' equity										0
Issuance of stock at the separation and distribution										1
Stockholders' equity	1									1
Common Stock Par Value | Parent Company
Stockholders' equity										0
Issuance of stock at the separation and distribution										1
Stockholders' equity	1									1
Common Stock Par Value | Guarantor Subsidiaries
Stockholders' equity	0	0								0		0
Common Stock Par Value | Non-Guarantor Subsidiaries
Stockholders' equity	0	0								0		0
Common Stock Par Value | Consolidation, Eliminations
Stockholders' equity	0	0								0		0
Additional Paid-in Capital
Stockholders' equity										0
Issuance of stock at the separation and distribution										-1
Adjustment to Additional Paid in Capital from Net Parent Investment										395
Stock-based compensation expense										1
Stockholders' equity	395									395
Additional Paid-in Capital | Parent Company
Stockholders' equity										0
Issuance of stock at the separation and distribution										-1
Additional paid-in capital (APIC)	395									395
Stock-based compensation expense										1
Stockholders' equity	395									395
Additional Paid-in Capital | Guarantor Subsidiaries
Additional paid-in capital (APIC)	1,038									1,038
Stockholders' equity	1,038	0								1,038		0
Additional Paid-in Capital | Non-Guarantor Subsidiaries
Additional paid-in capital (APIC)	544									544
Stockholders' equity	544	0								544		0
Additional Paid-in Capital | Consolidation, Eliminations
Additional paid-in capital (APIC)	-1,582									-1,582
Stockholders' equity	-1,582	0								-1,582		0
Accumulated Other Comprehensive Income (Loss)
Stockholders' equity					155				162	165	155	155	162	138
Net income												0	0	0
Net transfers to Valero												0	0	0
Other comprehensive loss										-30		10	-7	24
Stockholders' equity	135	165				155				135		165	155	162
Accumulated Other Comprehensive Income (Loss) | Parent Company
Stockholders' equity										0
Adjustment to Additional Paid in Capital from Net Parent Investment										165
Other comprehensive loss										-30
Stockholders' equity	135									135
Accumulated Other Comprehensive Income (Loss) | Guarantor Subsidiaries
Stockholders' equity					0				0		0	0	0	0
Net income												0	0	0
Net transfers to Valero												0	0	0
Other comprehensive loss												0	0	0
Stockholders' equity	0	0				0				0		0	0	0
Accumulated Other Comprehensive Income (Loss) | Non-Guarantor Subsidiaries
Stockholders' equity					155				162	165	155	155	162	138
Net income												0	0	0
Net transfers to Valero												0	0	0
Adjustment to Additional Paid in Capital from Net Parent Investment										-165
Other comprehensive loss												10
Stockholders' equity	0	165				155				0		165	155	162
Accumulated Other Comprehensive Income (Loss) | Consolidation, Eliminations
Stockholders' equity	0	0								0		0
Net Parent Investment
Stockholders' equity					1,094				1,031	1,082	1,094	1,094	1,031	1,059
Net income										44		210	214	193
Net transfers to Valero										-731		-222	-151	-221
Adjustment to Additional Paid in Capital from Net Parent Investment										-395
Other comprehensive loss												0	0	0
Stockholders' equity	0	1,082				1,094				0		1,082	1,094	1,031
Net Parent Investment | Parent Company
Stockholders' equity										0
Net transfers to Valero										395
Adjustment to Additional Paid in Capital from Net Parent Investment										-395
Stockholders' equity	0									0
Net Parent Investment | Guarantor Subsidiaries
Stockholders' equity					861				807	866	861	861	807	823
Net income										17
Net transfers to Valero										155		-122	-47	-116
Adjustment to Additional Paid in Capital from Net Parent Investment										-1,038
Other comprehensive loss												0	0	0
Stockholders' equity		866				861						866	861	807
Net Parent Investment | Non-Guarantor Subsidiaries
Stockholders' equity					233				224	216	233	233	224	236
Net income										27
Net transfers to Valero										301		-100	-104	-105
Adjustment to Additional Paid in Capital from Net Parent Investment										-544
Other comprehensive loss												0	0	0
Stockholders' equity		216				233						216	233	224
Net Parent Investment | Intersegment Elimination [Member]
Stockholders' equity										0
Net income										0
Net transfers to Valero										-1,582
Adjustment to Additional Paid in Capital from Net Parent Investment										1,582
Retained Earnings
Stockholders' equity										0
Net income										20
Stockholders' equity	20									20
Retained Earnings | Parent Company
Stockholders' equity										0
Net income										20
Stockholders' equity	20									20
Retained Earnings | Guarantor Subsidiaries
Stockholders' equity										0
Net income										17
Stockholders' equity	17									17
Retained Earnings | Non-Guarantor Subsidiaries
Stockholders' equity										0
Net income										11
Stockholders' equity	11									11
Retained Earnings | Intersegment Elimination [Member]
Stockholders' equity										0
Net income										-28
Stockholders' equity	($28)									($28)