Debt and Credit Agreements (Tables)

3 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Commercial Paper Borrowings

The Registrants had the following amounts of commercial paper borrowings outstanding as of March 31, 2018 and December 31, 2017:

Commercial Paper Borrowings	March 31, 2018		December 31, 2017
Exelon	$	1,154	$	427
Generation	165		—
ComEd	317		—
PECO	220		—
BGE	45		77
PHI(a)	407		350
Pepco	60		26
DPL	211		216
ACE	136		108

Schedule of Long-term Debt Instruments [Table Text Block]

During the three months endedMarch 31, 2018, the following long-term debt was issued:

Company	Type	Interest Rate		Maturity	Amount		Use of Proceeds
Generation	Energy Efficiency Project Financing	3.72	%	April 30, 2018	$	1	Funding to install energy conservation measures for the Smithsonian Zoo project.
Generation	Energy Efficiency Project Financing	3.17	%	April 30, 2018	$	1	Funding to install energy conservation measures in Brooklyn, NY.
Generation	Energy Efficiency Project Financing	2.61	%	September 30, 2018	$	2	Funding to install energy conservation measures for the Pensacola project.
ComEd	First Mortgage Bonds, Series 124	4.00	%	March 1, 2048	$	800	Refinance one series of maturing first mortgage bonds, to repay a portion of ComEd’s outstanding commercial paper obligations and to fund general corporate purposes.
PECO	First and Refunding Mortgage Bonds	3.90	%	March 1, 2048	$	325	Refinance a portion of maturing mortgage bonds.