Incentive Plans - Narrative (Details)		1 Months Ended	12 Months Ended			20 Months Ended
	Aug. 30, 2013 USD ($) shares	Feb. 29, 2024 peer_company $ / shares	Dec. 31, 2025 USD ($) $ / shares shares	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2024 shares	May 04, 2023 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)			28,900
Compensation charged against income before income tax benefit | $			$ 28,600,000	$ 22,900,000	$ 21,800,000
Unrecognized compensation cost related to stock option awards | $			$ 18,300,000
Unrecognized compensation cost related to stock option awards, weighted average period for recognition (in years)			2 years 2 months 12 days
Total income tax benefits realized from tax deductions related to stock option exercises under share-based payment arrangements | $			$ 400,000	$ 1,100,000	$ 800,000
2013 Long-Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares authorized for incentive plan (in shares)	5,500,000
Maximum number of shares per employee (in shares)	1,000,000
Maximum amount payable | $	$ 5,000,000
2023 Omnibus Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares authorized for incentive plan (in shares)							1,725,000
Shares granted (in shares)						191,075
Shares available for grant (in shares)			1,533,925
2023 Omnibus Incentive Compensation Plan | DSUs | Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share of common stock right			1
Granted (in shares)			865
Compensation charged against income before income tax benefit | $			$ 400,000
Outstanding (in shares)			2,604
Weighted average grant date fair value (in dollars per share) | $ / shares			$ 399.79
MUSA 2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option term (in years)			7 years
MUSA 2013 Plan | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)			3 years
MUSA 2013 Plan | RSUs | Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)			1 year
MUSA 2013 Plan | Return On Average Capital Employed Performance Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)		3 years
MUSA 2013 Plan | Return On Average Capital Employed Performance Units | ROACE
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units issued, weighted average grant date fair value (in dollars per share) | $ / shares		$ 492.22
MUSA 2013 Plan | Total Shareholder Return Performance Units
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 | peer_company		17
MUSA 2013 Plan | Total Shareholder Return Performance Units | TSR
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units issued, weighted average grant date fair value (in dollars per share) | $ / shares		$ 674.28
2013 Directors Plan | RSUs | Non-employee directors | Prior to 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)			3 years
2013 Directors Plan | RSUs | Non-employee directors | In 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (in years)			1 year
2013 Directors Plan | DSUs | Non-employee directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share of common stock right			1
Outstanding (in shares)			426
Weighted average grant date fair value (in dollars per share) | $ / shares			$ 259.87