Background and Nature of Operations - Narrative (Details)		12 Months Ended
	Oct. 31, 2024 $ / shares shares	Dec. 31, 2024 segment $ / shares shares	Oct. 30, 2024 shares	Dec. 31, 2023 $ / shares shares
Product Information [Line Items]
Number of operating segments | segment		2
Number of reportable segments | segment		2
Common stock, issued (in shares) | shares	50,972,059	50,980,924	1,000	1,000
Common stock, outstanding (in shares) | shares	50,972,059	50,980,924	1,000	1,000
Common stock, stated value (in dollars per share) | $ / shares	$ 0.01	$ 0.01		$ 1
MDU Resources Shareholders
Product Information [Line Items]
Common stock distribution ratio	0.25