Incentive Plans - Schedule of Valuation Assumptions (Details) - MUSA 2013 Plan - $ / shares	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per option grant (in dollars per share)	$ 154.07	$ 133.91	$ 88.53
Dividend yield	0.40%	0.40%	0.50%
Expected volatility	27.90%	32.90%	33.10%
Risk-free interest rate	4.50%	4.30%	3.80%
Expected life (years)	4 years 9 months 18 days	4 years 9 months 18 days	4 years 10 months 24 days
Stock price at valuation date (usd per share)	$ 492.22	$ 391.54	$ 263.48