Financing: Summary of ATM Activity (Details) - Common Stock - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
At The Market Equity Offering Program [Line Items]
Proceeds, (net of issuance costs)	$ 219,600,000	$ 181,600,000	$ 118,700,000
Number of shares issued	3,700,000	3,300,000	2,000,000
Average price per share	$ 59.56	$ 55.63	$ 59.04
Payments of Stock Issuance Costs	$ (2,400,000)	$ (1,800,000)	$ (1,200,000)
August 4, 2020 ATM Program
At The Market Equity Offering Program [Line Items]
Proceeds, (net of issuance costs)	$ 0	$ 0	$ 48,500,000
Number of shares issued	0	0	800,000
Payments of Stock Issuance Costs	$ 0	$ 0	$ (500,000)
June 16, 2023 ATM Program
At The Market Equity Offering Program [Line Items]
Proceeds, (net of issuance costs)	$ 45,700,000	$ 181,600,000	$ 70,200,000
Number of shares issued	800,000	3,300,000	1,200,000
Payments of Stock Issuance Costs	$ (600,000)	$ (1,800,000)	$ (700,000)
May 8, 2025 ATM Program
At The Market Equity Offering Program [Line Items]
Proceeds, (net of issuance costs)	$ 173,900,000	$ 0	$ 0
Number of shares issued	2,900,000	0	0
Payments of Stock Issuance Costs	$ (1,800,000)	$ 0	$ 0