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Financing: Summary of ATM Activity (Details) - Common Stock - USD ($) $ / shares in Units, $ in Millions | 12 Months Ended
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Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Number of shares issued | 1,307,755 | 1,812,197 | 0
Average price per share | $ 69.74 | $ 66.18 | $ 0
Proceeds, (net of issuance costs) | $ 90.3 | $ 118.8 | $ 0.0

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