Risk Management and Derivatives: Cash Flow Hedges (Details) - Cash Flow Hedging - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Interest rate swaps
Derivative [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months			$ 3.0
Designated as Hedging Instrument
Derivative [Line Items]
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	$ 0.5	$ 1.3	1.7	$ 4.4
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(0.9)	(1.3)	(2.0)	(4.6)
Designated as Hedging Instrument \| Interest rate swaps
Derivative [Line Items]
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	0.8	0.7	1.4	1.4
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	(0.8)	(0.7)	(1.4)	(1.4)
Designated as Hedging Instrument \| Commodity Contract
Derivative [Line Items]
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	(0.3)	0.6	0.3	3.0
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	$ (0.1)	$ (0.6)	$ (0.6)	$ (3.2)

Derivative instruments gain losses reclassified from accumulated OCI into income effective portion net.

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- Definition

Derivative instruments losses reclassified from accumulated OCI into income effective portion.

+ References

No definition available.

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- Definition

Unrealized gain losses on cash flow hedging instruments.

+ References

No definition available.

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- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480870/815-30-50-1

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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.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480682/815-20-25-6A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-5

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