Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

Property, Pland and Equipment with Useful Life Classification

The following table summarizes the components of the electric generation and distribution assets and other property, plant and equipment (in millions) with their estimated useful lives (in years). The amounts are stated net of all prior asset impairment losses recognized.

	Estimated Useful Life	December 31,
	(in years)	2020		2019
Electric generation and distribution facilities	5-40	$	24,239	$	22,869
Other buildings	5-51	1,507		1,612
Furniture, fixtures and equipment	3-30	333		319
Other	5-39	628		583
Total electric generation and distribution assets and other		26,707		25,383
Accumulated depreciation		(8,472)		(8,505)
Net electric generation and distribution assets and other		$	18,235	$	16,878

Interest Capitalized During Development And Construction

The following table summarizes depreciation expense (including the amortization of assets recorded under finance leases in 2020 and 2019 or capital leases in 2018, and the amortization of asset retirement obligations) and interest capitalized during development and construction on qualifying assets for the periods indicated (in millions):

Years Ended December 31,	2020		2019		2018
Depreciation expense	$	1,004	$	977	$	960
Interest capitalized during development and construction	307		238		199

Net Asset Value Of Regulated And Non-Regulated Assets And Accumulated Depreciation

The following table summarizes regulated and non-regulated generation and distribution property, plant and equipment and accumulated depreciation as of the dates indicated (in millions):

December 31,	2020		2019
Regulated generation and distribution assets and other, gross	$	8,858	$	8,570
Regulated accumulated depreciation	(3,329)		(3,029)
Regulated generation and distribution assets and other, net	5,529		5,541
Non-regulated generation and distribution assets and other, gross	17,849		16,813
Non-regulated accumulated depreciation	(5,143)		(5,476)
Non-regulated generation and distribution assets and other, net	12,706		11,337
Net electric generation and distribution assets and other	$	18,235	$	16,878