Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Summary of Accounting poliicies [Abstract]

Property, Plant and Equipment [Table Text Block]

A summary of property, plant and equipment for continuing operations by classification as of December 31, 2019 and 2018 is provided in the following table:

	As of December 31,
(in thousands)	2019			2018
Property, plant and equipment
Regulated Energy
Natural gas distribution - Delmarva Peninsula and Florida	$	705,095		$	657,630
Natural gas transmission - Delmarva Peninsula, Pennsylvania and Florida	608,727			537,654
Electric distribution	127,651			102,133
Unregulated Energy
Propane operations – Mid-Atlantic and Florida	141,841			123,632
Natural gas transmission and supply – Ohio	73,658			70,225
Electricity and steam generation	35,436			35,239
Mobile CNG and pipeline solutions	14,014			7,240
Other unregulated energy	104			104
Other	40,006			34,584
Total property, plant and equipment	1,746,532			1,568,441
Less: Accumulated depreciation and amortization	(336,876		)	(294,089		)
Plus: Construction work in progress	54,141			79,168
Net property, plant and equipment	$	1,463,797		$	1,353,520

Annual Depreciation Rates Table [Table Text Block]

Depreciation and Accretion Included in Operations Expenses

We compute depreciation expense for our regulated operations by applying composite, annual rates, as approved by the respective regulatory bodies. The following table shows the average depreciation rates used for regulated operations during the years ended December 31, 2019, 2018 and 2017:

	2019	2018	2017
Natural gas distribution – Delmarva Peninsula	2.5%	2.5%	2.5%
Natural gas distribution – Florida	2.6%	2.9%	2.9%
Natural gas transmission – Delmarva Peninsula	2.6%	2.7%	2.8%
Natural gas transmission – Florida	2.4%	2.3%	3.5%
Electric distribution	3.4%	3.4%	3.4%

Estimated Useful Life Of Assets Table [Table Text Block]

For our unregulated operations, we compute depreciation expense on a straight-line basis over the following estimated useful lives of the assets:

Asset Description	Useful Life
Propane distribution mains	10-37 years
Propane bulk plants and tanks	10-40 years
Propane equipment, meters and meter installations	5-33 years
Measuring and regulating station equipment	5-37 years
Natural gas pipelines	45 years
Natural gas right of ways	Perpetual
CHP plant	30 years
Natural gas processing equipment	20-25 years
Office furniture and equipment	3-10 years
Transportation equipment	4-20 years
Structures and improvements	5-45 years
Other	Various