Electric utility segment - Unconsolidated Variable Interest Entities (Details)	3 Months Ended		12 Months Ended
	Jun. 30, 2021 MW	Mar. 31, 2021 MW	Dec. 31, 2021 entity agreement
Variable Interest Entity [Line Items]
Number of consolidation VIEs | entity			3
Puna Geothermal Venture Power Purchase Agreement
Variable Interest Entity [Line Items]
Firm capacity volume | MW	23.9	13.0
Subsidiaries
Variable Interest Entity [Line Items]
Number of power purchase agreements (PPAs) (in agreements) | agreement			5