CONSOLIDATED STATEMENTS OF CASH FLOWS (Constellation Energy Group, Inc. and Subsidiaries) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash Flows From Operating Activities
Net (loss) income	$ (306.8)	$ (931.8)	$ 4,503.4
Adjustments to reconcile to net cash provided by operating activities
Depreciation, depletion, accretion, and amortization	589.3	519.5	651.4
Amortization of nuclear fuel			117.9
Amortization of energy contracts and derivatives designated as hedges	438.0	319.6	(138.4)
All 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 obligation expense	93.6	89.4	107.6
Defined benefit obligation payments	(114.9)	(324.0)	(372.5)
Merger costs	62.5		128.2
Workforce reduction costs			12.6
Impairment losses and other costs	891.0	2,476.8	124.7
Impairment losses on nuclear decommissioning trust assets			62.6
Gain on sale of 49.99% membership interest in CENG			(7,445.6)
(Gain) loss on divestitures	(57.3)	(245.8)	468.8
Gains on termination of contracts	(26.9)	(76.8)
Gain on U. S. Department of Energy settlement	(58.4)
Accrual of BGE residential customer credit			112.4
Equity in earnings of affiliates less than dividends received	9.1	14.1	15.5
Derivative contracts classified as financing activities	8.8	186.0	1,138.3
Changes in working capital
Accounts receivable, excluding margin	(268.8)	(236.5)	543.3
Derivative assets and liabilities, excluding collateral	775.3	449.9	425.3
Net collateral and margin	(245.0)	44.2	1,522.8
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)
Liability for unrecognized tax benefits	(40.8)	(66.6)	102.1
Accrued taxes and other current liabilities	(96.2)	(1,028.4)	788.8
Other	(67.8)	11.7	149.3
Net cash provided by operating activities	1,254.4	511.3	4,390.8
Cash Flows From Investing Activities
Investments in property, plant and equipment	(1,106.8)	(1,050.3)	(1,529.7)
Asset acquisitions and business combinations, net of cash acquired	(1,501.9)	(445.8)	(41.1)
Investments in nuclear decommissioning trust fund securities			(385.2)
Proceeds from nuclear decommissioning trust fund securities			366.5
Investments in joint ventures			(201.6)
Proceeds from sale of 49.99% membership interest in CENG			3,528.7
Proceeds from U. S. Department of Energy grant	40.6	54.7
Proceeds from sales of investments and other assets	105.8	244.0	88.3
Proceeds from investment tax credits and grants related to renewable energy investments	81.7	56.5
Payment for issuance of loans receivable	(75.0)
Proceeds from repayment of loans receivable	45.0
Contract and portfolio acquisitions	(3.7)	(208.3)	(2,153.7)
Decrease (increase) in restricted funds	51.8	(60.3)	1,003.3
Other	(17.7)	(35.7)	0.1
Net cash (used in) provided by investing activities	(2,380.2)	(1,445.2)	675.6
Cash Flows From Financing Activities
Net repayment of short-term borrowings	(12.1)	(13.6)	(809.7)
Proceeds from issuance of common stock	21.1	14.0	33.9
Proceeds from issuance of long-term debt	564.2	550.0	136.1
Common stock dividends paid	(182.6)	(183.3)	(228.0)
BGE preference stock dividends paid	(13.2)	(13.2)	(13.2)
Proceeds from contract and portfolio acquisitions	2.0	52.2	2,263.1
Repayment of long-term debt	(305.3)	(664.5)	(1,986.8)
Derivative contracts classified as financing activities	(8.8)	(186.0)	(1,138.3)
Debt and credit facility costs	(3.2)	(32.8)	(98.4)
Other	(0.3)	(0.4)	12.7
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 during the year for:
Interest (net of amounts capitalized)	265.3	289.5	369.5
Income taxes	$ (66.7)	$ 1,044.2	$ 57.1