Number Of Companies In Total Shareholder Return Peer Comparison Group

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Share Base Compensation Arrangement By Share Based Payment Awards, Maximum Amount Payable

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- Definition

Share Based Compensation Arrangement By Share Payment Awards, Number Of Plans

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Subparagraph (i)
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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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Disclosure of the aggregate tax benefit realized from the exercise of stock options and the conversion of similar instruments during the annual period.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

The highest quantity of shares an employee can purchase under the plan per period.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

Gross number of share options (or share units) granted during the period.

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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Incentive Plans (Narrative) (Details)	12 Months Ended			28 Months Ended
Incentive Plans (Narrative) (Details)	Dec. 31, 2015 USD ($) plan $ / shares company shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2013 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) plan company shares	Feb. 12, 2014 shares	Aug. 30, 2013 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share based compensation plans \| plan	2			2
Shares granted	72,350	127,400
Unrecognized compensation cost related to stock option awards \| $	$ 12,934,000			$ 12,934,000
Unrecognized compensation cost related to stock option awards, weighted average period for recognition (in years)	2 years 3 months 18 days
Related income tax benefit recognized in income \| $	$ 3,155,000	$ 3,652,000	$ 3,287,000
Total income tax benefits realized from tax deductions related to stock option exercises under share-based payment arrangements \| $	$ 3,109,000	$ 470,000
2013 Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares authorized for incentive plan					5,500,000.0	10,000,000
Maximum number of shares per employee	1,000,000
Maximum amount payable \| $	$ 5,000,000
Shares granted				1,563,828
Shares available for grant	4,074,288			4,074,288
2013 Stock Plan For Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares authorized for incentive plan	500,000			500,000
Award vesting period (in years)	3 years
Shares available for grant	436,226			436,226
Restricted stock units issued				63,774
2013 Stock Plan For Non-Employee Directors [Member] \| Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units issued	12,924	22,437	28,413
MUSA 2013 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units issued	55,450	93,025	352,522
Option term (in years)	7 years
MUSA 2013 Plan [Member] \| Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
MUSA 2013 Plan [Member] \| Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units issued	40,400	78,500
MUSA 2013 Plan [Member] \| Return On Average Capital Employed Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Restricted stock units issued, weighted average grant date fair value (in dollars per share) \| $ / shares	$ 70.57
MUSA 2013 Plan [Member] \| Total Shareholder Return Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	3 years
Number of companies in total shareholder return peer comparison group \| company	16			16
Restricted stock units issued, weighted average grant date fair value (in dollars per share) \| $ / shares	$ 100.33
Murphy Oil [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)	2 years
Related income tax benefit recognized in income \| $	$ 0	$ 0	$ 625,000
Minimum grant date fair value of options replaced (in dollars per share) \| $ / shares			$ 32.53
Maximum grant date fair value of options replaced (in dollars per share) \| $ / shares			$ 40.25