Long-Term Debt - Narrative (Details)					1 Months Ended	3 Months Ended		12 Months Ended
	Oct. 22, 2021 USD ($)	Apr. 19, 2021 USD ($)	Mar. 16, 2021 USD ($)	Jan. 01, 2021 USD ($)	Oct. 31, 2016 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Jan. 18, 2021 USD ($)	Dec. 31, 2020 USD ($)
Debt Instrument [Line Items]
Debt outstanding						$ 99,245,000		$ 99,519,000
Unamortized deferred financing costs						684,000		757,000
Debt repurchased						$ 274,000	$ 358,843,000
2.00% Convertible Senior Notes due October 2023
Debt Instrument [Line Items]
Interest rate, stated percentage					2.00%	2.00%	2.00%
Debt instrument, term					7 years
Convertible senior notes					$ 402,500,000
Debt outstanding					$ 375,800,000	$ 6,821,000		6,821,000
Interest rate, effective					3.10%
Equity component of convertible senior notes (reversal of equity component of convertible senior notes)					$ 26,700,000
Unamortized deferred financing costs					11,200,000
Issuance costs					$ 744,000
Debt repurchased	$ 26,900,000		$ 358,600,000				$ 358,600,000	395,700,000
Transaction cost								1,200,000
Write-off of debt financing cost			$ 3,700,000			0	$ 3,644,000
Debt instrument, fair value disclosure						$ 6,600,000		6,800,000
Convertible conversion ratio						0.1629223
Cumulative Effect, Period of Adoption, Adjustment | Retained Earnings
Debt Instrument [Line Items]
Balance as of period date										$ 7,000,000
Accounting Standards Update 2020-06 | 2.00% Convertible Senior Notes due October 2023
Debt Instrument [Line Items]
Equity component of convertible senior notes (reversal of equity component of convertible senior notes)				$ (26,700,000)
Hawaii Gas Business | Senior Notes
Debt Instrument [Line Items]
Transaction cost		$ 4,700,000
Write-off of debt financing cost		154,000
Debt repurchased, face amount		$ 100,000,000
Term Loan Facility | Hawaii Gas Business
Debt Instrument [Line Items]
Borrowing capacity						$ 80,000,000		80,000,000
Revolving Credit Facility
Debt Instrument [Line Items]
Borrowing capacity									$ 600,000,000
Revolving Credit Facility | Hawaii Gas Business
Debt Instrument [Line Items]
Undrawn portion of line of credit						$ 60,000,000		$ 60,000,000