Consolidated Balance Sheet (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Current Assets:
Cash and cash equivalents	$ 5		$ 30
Accounts receivable - trade (less allowance for doubtful accounts)	423		404
Unbilled revenue	265		304
Miscellaneous accounts and notes receivable	81		196
Materials and supplies	524		526
Current regulatory assets	295		156
Current accumulated deferred income taxes, net	352		106
Other current assets	86		85
Assets of discontinued operations (Note 16)	15		165
Total current assets	2,046		1,972
Property, Plant and Equipment, Net	17,424	[1]	16,205	[1]
Investments and Other Assets:
Nuclear decommissioning trust fund	549		494
Goodwill	411		411
Regulatory assets	1,582		1,240
Other assets	664		720
Total investments and other assets	3,206		2,865
TOTAL ASSETS	22,676		21,042
Current Liabilities:
Current maturities of long-term debt	120		534
Short-term debt	714		368
Accounts and wages payable	711		806
Taxes accrued	46		55
Interest accrued	85		86
Current regulatory liabilities	106		216
Other current liabilities	434		351
Liabilities of discontinued operations (Note 16)	33		45
Total current liabilities	2,249		2,461
Long-term Debt, Net	6,120		5,504
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes, net	3,923		3,250
Accumulated deferred investment tax credits	64		63
Regulatory liabilities	1,850		1,705
Asset retirement obligations	396		369
Pension and other postretirement benefits	705		466
Other deferred credits and liabilities	514		538
Total deferred credits and other liabilities	7,452		6,391
Commitments and Contingencies (Notes 2, 10, 14 and 15)
Stockholders' Equity:
Common stock	2		2
Other paid-in capital, principally premium on common stock	5,617		5,632
Preferred stock not subject to mandatory redemption	142		142
Retained earnings	1,103		907
Accumulated other comprehensive income (loss)	(9)		3
Total stockholders' equity	6,713		6,544
Noncontrolling Interests	142		142
Total equity	6,855		6,686
TOTAL LIABILITIES AND EQUITY	22,676		21,042
Union Electric Company
Current Assets:
Cash and cash equivalents	1		1
Accounts receivable - trade (less allowance for doubtful accounts)	190		191
Accounts receivable - affiliates	65		1
Unbilled revenue	146		168
Miscellaneous accounts and notes receivable	35		57
Materials and supplies	347		352
Current regulatory assets	163		118
Current accumulated deferred income taxes, net	49		20
Other current assets	92		71
Total current assets	1,039		959
Property, Plant and Equipment, Net	10,867	[1]	10,452	[1]
Investments and Other Assets:
Nuclear decommissioning trust fund	549		494
Regulatory assets	695		534
Other assets	391		465
Total investments and other assets	1,635		1,493
TOTAL ASSETS	13,541		12,904
Current Liabilities:
Current maturities of long-term debt	120		109
Due to Related Parties, Current	0		105
Short-term debt	97		0
Accounts and wages payable	405		387
Accounts payable - affiliates	56		30
Taxes accrued	32		220
Interest accrued	58		57
Current regulatory liabilities	18		57
Other current liabilities	117		82
Total current liabilities	903		1,047
Long-term Debt, Net	3,879		3,648
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes, net	2,806		2,524
Accumulated deferred investment tax credits	61		59
Regulatory liabilities	1,147		1,041
Asset retirement obligations	389		366
Pension and other postretirement benefits	274		189
Other deferred credits and liabilities	30		37
Total deferred credits and other liabilities	4,707		4,216
Commitments and Contingencies (Notes 2, 10, 14 and 15)
Stockholders' Equity:
Common stock	511		511
Other paid-in capital, principally premium on common stock	1,569		1,560
Preferred stock not subject to mandatory redemption	80		80
Retained earnings	1,892		1,842
Total stockholders' equity	4,052		3,993
TOTAL LIABILITIES AND EQUITY	13,541		12,904
Ameren Illinois Company
Current Assets:
Cash and cash equivalents	1		1
Accounts receivable - trade (less allowance for doubtful accounts)	212		201
Accounts receivable - affiliates	22		0
Unbilled revenue	119		135
Miscellaneous accounts and notes receivable	9		13
Materials and supplies	177		174
Current regulatory assets	129		38
Current accumulated deferred income taxes, net	160		45
Other current assets	15		26
Total current assets	844		633
Property, Plant and Equipment, Net	6,165		5,589
Investments and Other Assets:
Goodwill	411		411
Regulatory assets	883		701
Other assets	78		120
Total investments and other assets	1,372		1,232
TOTAL ASSETS	8,381		7,454
Current Liabilities:
Current maturities of long-term debt			0
Borrowings from money pool	15		56
Short-term debt	32
Accounts and wages payable	207		243
Accounts payable - affiliates	50		18
Taxes accrued	17		23
Customer deposits	77		79
Mark-to-market derivative liabilities	42		36
Environmental remediation	52		43
Current regulatory liabilities	84		159
Other current liabilities	124		114
Total current liabilities	700		771
Long-term Debt, Net	2,241		1,856
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes, net	1,408		1,116
Accumulated deferred investment tax credits	3		4
Regulatory liabilities	703		664
Pension and other postretirement benefits	277		197
Accrued Environmental Loss Contingencies, Noncurrent	199		232
Other deferred credits and liabilities	189		166
Total deferred credits and other liabilities	2,779		2,379
Commitments and Contingencies (Notes 2, 10, 14 and 15)
Stockholders' Equity:
Common stock	0		0
Other paid-in capital, principally premium on common stock	1,980		1,965
Preferred stock not subject to mandatory redemption	62		62
Retained earnings	611		410
Accumulated other comprehensive income (loss)	8		11
Total stockholders' equity	2,661		2,448
TOTAL LIABILITIES AND EQUITY	$ 8,381		$ 7,454

[1] (a)Amounts in Ameren and Ameren Missouri include two CTs under separate capital lease agreements. The gross cumulative asset value of those agreements was $233 million and $228 million at December 31, 2014 and 2013, respectively. The total accumulated depreciation associated with the two CTs was $66 million and $56 million at December 31, 2014 and 2013, respectively. In addition, Ameren Missouri has investments in debt securities, which were classified as held-to-maturity, related to the two CTs from the city of Bowling Green and Audrain County. As of December 31, 2014 and 2013, the carrying value of these debt securities was $294 million and $299 million, respectively.