Revenue Recognition Disegragation of Revenue (Details) - USD ($)	3 Months Ended				6 Months Ended
	Jun. 30, 2022		Jun. 30, 2021		Jun. 30, 2022		Jun. 30, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 139,470,000		$ 111,082,000		$ 362,350,000		$ 302,268,000
Revenue from Contract with Customer, Excluding Assessed Tax	139,470,000	[1]	111,082,000	[1]	362,350,000	[2]	302,268,000	[2]
Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	92,193,000	[1]	80,910,000	[1]	220,084,000	[2]	202,107,000	[2]
Unregulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	53,463,000	[1]	34,773,000	[1]	154,756,000	[2]	109,531,000	[2]
Other Segments And Intersegments Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(6,186,000)		(4,601,000)		(12,490,000)		(9,370,000)
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(6,186,000)	[1]	(4,601,000)	[1]	(12,490,000)	[2]	(9,370,000)	[2]
Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(19,276,000)		(17,834,000)		(40,466,000)		(36,794,000)
Eliminations [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(12,980,000)		(13,168,000)		(27,769,000)		(27,268,000)
Other [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenues	(100,000)		100,000		100,000		(200,000)
Other [Member] | Unregulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenues	100,000				200,000		200,000
Revenue from Contract with Customer, Excluding Assessed Tax	(110,000)		(65,000)		(207,000)		(156,000)
Energy Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	79,152,000		68,804,000		194,476,000		177,616,000
Energy Distribution [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	79,152,000		68,804,000		194,476,000		177,616,000
Energy Distribution [Member] | Delaware natural gas division [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	13,086,000		10,068,000		47,568,000		43,340,000
Energy Distribution [Member] | Delaware natural gas division [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	13,086,000		10,068,000		47,568,000		43,340,000
Energy Distribution [Member] | Central Florida Gas Division [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	9,619,000		8,446,000		19,885,000		17,402,000
Energy Distribution [Member] | Central Florida Gas Division [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	9,619,000		8,446,000		19,885,000		17,402,000
Energy Distribution [Member] | FPU Electric Distribution [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	20,305,000		18,898,000		39,394,000		37,449,000
Energy Distribution [Member] | FPU Electric Distribution [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	20,305,000		18,898,000		39,394,000		37,449,000
Energy Distribution [Member] | Florida Public Utilities Company [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	25,817,000		23,159,000		55,837,000		50,020,000
Energy Distribution [Member] | Florida Public Utilities Company [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	25,817,000		23,159,000		55,837,000		50,020,000
Energy Distribution [Member] | Maryland Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,372,000		3,224,000		14,836,000		13,690,000
Energy Distribution [Member] | Maryland Natural Gas [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,372,000		3,224,000		14,836,000		13,690,000
Energy Distribution [Member] | Sandpiper [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,248,000		3,814,000		11,885,000		11,885,000
Energy Distribution [Member] | Sandpiper [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	4,248,000		3,814,000		11,885,000		11,885,000
Energy Distribution [Member] | Elkton Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,705,000				5,071,000
Energy Distribution [Member] | Elkton Gas [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,705,000		1,195,000		5,071,000		3,830,000
Energy Transmission [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	36,829,000		30,852,000		82,221,000		70,243,000
Energy Transmission [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	26,021,000		25,274,000		53,377,000		51,759,000
Energy Transmission [Member] | Unregulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	10,808,000		5,578,000		28,844,000		18,484,000
Energy Transmission [Member] | Aspire [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	10,808,000		5,578,000		28,844,000		18,484,000
Energy Transmission [Member] | Aspire [Member] | Unregulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	10,808,000		5,578,000		28,844,000		18,484,000
Energy Transmission [Member] | Eastern Shore Gas Company [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	18,875,000		18,617,000		39,196,000		38,589,000
Energy Transmission [Member] | Eastern Shore Gas Company [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	18,875,000		18,617,000		39,196,000		38,589,000
Energy Transmission [Member] | Peninsula Pipeline [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	6,777,000		6,610,000		13,549,000		13,077,000
Energy Transmission [Member] | Peninsula Pipeline [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	6,777,000		6,610,000		13,549,000		13,077,000
Energy Transmission [Member] | Aspire Energy Express | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	369,000		47,000		632,000		93,000
Energy Generation [Member] | Eight Flags [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	5,916,000		4,173,000		11,455,000		8,502,000
Energy Generation [Member] | Eight Flags [Member] | Unregulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	5,916,000		4,173,000		11,455,000		8,502,000
Propane Delivery [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	34,469,000		23,098,000		110,075,000		78,361,000
Propane Delivery [Member] | Florida Propane | Unregulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	34,469,000		23,098,000		110,075,000		78,361,000
Energy Services [Member] | Marlin Gas Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,380,000				4,589,000
Energy Services [Member] | Marlin Gas Services [Member] | Unregulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,380,000		1,989,000		4,589,000		4,340,000
Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(19,361,000)		(17,967,000)		(40,682,000)		(37,059,000)
Eliminations [Member] | Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(12,980,000)		(13,168,000)		(27,769,000)		(27,268,000)
Eliminations [Member] | Unregulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(110,000)		(65,000)		(207,000)		(156,000)
Eliminations [Member] | Eliminations [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	(6,271,000)		(4,734,000)		(12,706,000)		(9,635,000)
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	85,000		133,000		216,000		265,000
Other [Member] | Unregulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax					0		0
Other [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 85,000		$ 133,000		$ 216,000		$ 265,000

[1] (1) Total operating revenues for the three months ended June 30, 2022, include other revenue (revenues from sources other than contracts with customers) of $(0.1) million for Regulated and $0.1 million Unregulated Energy segments, respectively, and $0.1 million for both our Regulated and Unregulated Energy segments, respectively, for the three months ended June 30, 2021. The sources of other revenues include revenue from alternative revenue programs related to revenue normalization for the Maryland division and Sandpiper Energy and late fees.

[2] 1) Total operating revenues for the six months ended June 30, 2022, include other revenue (revenues from sources other than contracts with customers) of $0.1 million for Regulated and $0.2 million Unregulated Energy segments, respectively, and $(0.2) million and $0.2 million for our Regulated and Unregulated Energy segments, respectively, for the six months ended June 30, 2021. The sources of other revenues include revenue from alternative revenue programs related to revenue normalization for the Maryland division and Sandpiper Energy and late fees