XML 63 R48.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Description of Business and Basis of Presentation (Details) |  |  | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Aug. 31, 2013 | Aug. 30, 2013 | Mar. 31, 2013 USD ($) $ / shares shares | Oct. 31, 2009 gal | Dec. 31, 2015 state store $ / shares gal | Dec. 31, 2012 gal | Dec. 31, 2014 $ / shares
Description of Business and Basis of Presentation [Line Items] |  |  |  |  |  |  |
Percentage of shares of stock distributed |  | 100.00% |  |  |  |  |
Stock conversion ratio |  | 0.25 |  |  |  |  |
Ownership interest after transaction (percent) | 0.00% |  |  |  |  |  |
Number of states in which entity operates | state |  |  |  |  | 24 |  |
Number of stations | store |  |  |  |  | 1,335 |  |
Common stock shares issued | shares |  |  | 100 |  |  |  |
Common stock par value (in dollars per share) | $ / shares |  |  | $ 0.01 |  | $ 0.01 |  | $ 0.01
Proceeds from issuance of common stock | $ |  |  | $ 1.00 |  |  |  |
North Dakota [Member] |  |  |  |  |  |  |
Description of Business and Basis of Presentation [Line Items] |  |  |  |  |  |  |
Per annum production capacity of facility (in gallons per year) |  |  |  | 110,000,000 |  | 135,000,000 |
Texas [Member] |  |  |  |  |  |  |
Description of Business and Basis of Presentation [Line Items] |  |  |  |  |  |  |
Per annum production capacity of facility (in gallons per year) |  |  |  |  | 105,000,000 |  |

X
- Definition Description Of Business And Basis Of Presentation [Line Items] + References No definition available. + Details
Name: | musa_DescriptionOfBusinessAndBasisOfPresentationLineItems
Namespace Prefix: | musa_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Gallons produced per year + References No definition available. + Details
Name: | musa_PerAnnumProductionCapacityOfFacility
Namespace Prefix: | musa_
Data Type: | num:volumeItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage Of Shares Of Stock Distributed + References No definition available. + Details
Name: | musa_PercentageOfSharesOfStockDistributed
Namespace Prefix: | musa_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Spin Off, Stock Conversion Ratio + References No definition available. + Details
Name: | musa_SpinOffStockConversionRatio
Namespace Prefix: | musa_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Face amount or stated value per share of common stock. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 + Details
Name: | us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of states the entity operates in as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the number of stores. + References No definition available. + Details
Name: | us-gaap_NumberOfStores
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of subsidiary's or equity investee's stock owned by parent company after stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of new stock issued during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementGeographicalAxis=stpr_ND
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=stpr_TX
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |