Cash Taxes Paid (Details) $ in Millions	12 Months Ended
	Dec. 31, 2025 USD ($)
Income Tax Disclosure [Abstract]
Income Taxes Paid, Net	$ 36.6
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income Taxes Paid, Net	36.6
Federal
Income Tax Disclosure [Abstract]
Income Taxes Paid, Net	29.5
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income Taxes Paid, Net	29.5
State, Montana
Income Tax Disclosure [Abstract]
Income Taxes Paid, Net	4.0
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income Taxes Paid, Net	4.0
State, Other
Income Tax Disclosure [Abstract]
Income Taxes Paid, Net	3.1
Income Tax Paid, by Individual Jurisdiction [Line Items]
Income Taxes Paid, Net	$ 3.1