CONSOLIDATED STATEMENTS OF CASH FLOWS (Baltimore Gas and Electric Company) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Adjustments to reconcile to net cash provided by operating activities
Depreciation and amortization	$ 589.3	$ 519.5	$ 651.4
Other amortization	39.4	33.3	135.7
Deferred income taxes	(193.7)	(716.3)	1,847.0
Investment tax credit adjustments	(4.3)	(4.5)	(12.1)
Deferred fuel costs	5.0	67.4	68.9
Deferred storm costs	(15.5)
Defined benefit plan expenses	93.6	89.4	107.6
Accrual of residential customer rate credit			112.4
Impairment losses and other costs	891.0	2,476.8	124.7
Changes in:
Materials, supplies, and fuel stocks	34.7	0.1	220.6
Other current assets	5.5	(150.0)	217.2
Accounts payable	(201.4)	80.0	(1,105.0)
Other current liabilities	(96.2)	(1,028.4)	788.8
Net cash provided by operating activities	1,254.4	511.3	4,390.8
Cash Flows From Investing Activities
Proceeds from sales of investments and other assets	105.8	244.0	88.3
Increase in restricted funds	51.8	(60.3)	1,003.3
Net cash used in investing activities	(2,380.2)	(1,445.2)	675.6
Cash Flows From Financing Activities
Proceeds from issuance of long-term debt	564.2	550.0	136.1
Repayment of long-term debt	(305.3)	(664.5)	(1,986.8)
Debt issuance costs	(3.2)	(32.8)	(98.4)
Preference stock dividends paid	(13.2)	(13.2)	(13.2)
Net cash provided by (used in) financing activities	61.8	(477.6)	(1,828.6)
Net (Decrease) Increase in Cash and Cash Equivalents	(1,064.0)	(1,411.5)	3,237.8
Cash and Cash Equivalents at Beginning of Year	2,028.5	3,440.0	202.2
Cash and Cash Equivalents at End of Year	964.5	2,028.5	3,440.0
Cash paid (received) during the year for:
Interest (net of amounts capitalized)	265.3	289.5	369.5
Income taxes	(66.7)	1,044.2	57.1
Baltimore Gas and Electric Company
Cash Flows From Operating Activities
Net income	135.7	147.6	90.7
Adjustments to reconcile to net cash provided by operating activities
Depreciation and amortization	272.1	249.2	262.1
Other amortization	7.3	5.2	9.2
Deferred income taxes	145.8	300.2	184.7
Investment tax credit adjustments	(1.0)	(1.1)	(1.1)
Deferred fuel costs	5.0	67.4	68.9
Deferred storm costs	(15.5)
Defined benefit plan expenses	35.7	36.0	32.7
Allowance for equity funds used during construction	(15.1)	(10.5)	(8.2)
Accrual of residential customer rate credit			112.4
Impairment losses and other costs			20.0
Changes in:
Accounts receivable	103.4	(57.6)	(5.1)
Accounts receivable, affiliated companies	(0.6)	14.3	(11.1)
Materials, supplies, and fuel stocks	(9.6)	8.0	76.4
Income taxes receivable, net	34.7	(55.9)
Other current assets	(87.6)	(6.6)	(10.2)
Accounts payable	(43.3)	87.5	(65.0)
Accounts payable, affiliated companies	(18.8)	(13.4)	1.3
Other current liabilities	15.3	(121.5)	62.7
Long-term receivables and payables, affiliated companies	(53.0)	(200.8)	(197.8)
Regulatory assets, net	9.9	(64.3)	(44.4)
Other	(89.2)	(64.9)	67.6
Net cash provided by operating activities	431.2	318.8	645.8
Cash Flows From Investing Activities
Utility construction expenditures (excluding equity portion of allowance for funds used during construction)	(588.0)	(551.5)	(372.6)
Proceeds from U.S. Department of Energy grant	40.6	54.7
Change in cash pool at parent		314.7	(165.9)
Proceeds from sales of investments and other assets		20.9
Increase in restricted funds	(0.2)	(5.2)	(0.6)
Net cash used in investing activities	(547.6)	(166.4)	(539.1)
Cash Flows From Financing Activities
Net repayment of short-term borrowings		(46.0)	(324.0)
Proceeds from issuance of long-term debt	300.0
Repayment of long-term debt	(81.7)	(56.5)	(90.0)
Debt issuance costs	(5.1)	(0.3)	(0.5)
Contribution from noncontrolling interest			8.0
Preference stock dividends paid	(13.2)	(13.2)	(13.2)
(Distribution to) contribution from parent	(85.0)		315.9
Net cash provided by (used in) financing activities	115.0	(116.0)	(103.8)
Net (Decrease) Increase in Cash and Cash Equivalents	(1.4)	36.4	2.9
Cash and Cash Equivalents at Beginning of Year	50.0	13.6	10.7
Cash and Cash Equivalents at End of Year	48.6	50.0	13.6
Cash paid (received) during the year for:
Interest (net of amounts capitalized)	122.3	127.9	136.9
Income taxes	$ (53.6)	$ (76.0)	$ (250.9)