Revenue from Contracts with Customers Revenue from Contracts with Customers (Tables)

3 Months Ended

Mar. 31, 2018

Revenue from Contract with Customer [Abstract]

Contract with Customer, Asset and Liability [Table Text Block]

The following table provides a rollforward of the contract assets reflected on Exelon's and Generation's Consolidated Balance Sheets from January 1, 2018 to March 31, 2018:

Contract Assets	Exelon and Generation
Balance as of January 1, 2018	$	283
Increases as a result of changes in the estimate of the stage of completion	28
Amounts reclassified to receivables	(9		)
Balance at March 31, 2018	$	302

The following table provides a rollforward of the contract liabilities reflected on Exelon's and Generation's Consolidated Balance Sheet from January 1, 2018 to March 31, 2018:

Contract Liabilities	Exelon and Generation
Balance as of January 1, 2018	$	35
Increases as a result of additional cash received or due	227
Amounts recognized into revenues	(216		)
Balance at March 31, 2018	$	46

Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]

	2019		2020		2021		2022		2023 and thereafter		Total
Exelon	$	544	$	264	$	104	$	46	$	128	$	1,086
Generation	544		264		104		46		128		$	1,086