Consolidated Balance Sheet (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current Assets:
Cash and cash equivalents	$ 6	$ 5
Accounts receivable - trade (less allowance for doubtful accounts)	524	423
Unbilled revenue	212	265
Miscellaneous accounts and notes receivable	100	81
Materials and supplies	449	524
Current regulatory assets	265	295
Current accumulated deferred income taxes, net	331	352
Other current assets	91	86
Assets of discontinued operations (Note 12)	15	15
Total current assets	1,993	2,046
Property and Plant, Net	17,700	17,424
Investments and Other Assets:
Nuclear decommissioning trust fund	558	549
Goodwill	411	411
Regulatory assets	1,577	1,582
Other assets	645	664
Total investments and other assets	3,191	3,206
TOTAL ASSETS	22,884	22,676
Current Liabilities:
Current maturities of long-term debt	380	120
Short-term Debt	955	714
Accounts and wages payable	434	711
Taxes accrued	79	46
Interest accrued	94	85
Current regulatory liabilities	107	106
Other current liabilities	437	434
Liabilities of discontinued operations (Note 12)	34	33
Total current liabilities	2,520	2,249
Long-term Debt, Net	5,860	6,120
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes, net	3,964	3,923
Accumulated deferred investment tax credits	65	64
Regulatory liabilities	1,897	1,850
Asset retirement obligations	500	396
Pension and other postretirement benefits	708	705
Other deferred credits and liabilities	524	514
Total deferred credits and other liabilities	7,658	7,452
Commitments and Contingencies
Stockholders' Equity:
Common Stock	2	2
Other paid-in capital	5,600	5,617
Retained earnings	1,111	1,103
Accumulated other comprehensive income (loss)	(9)	(9)
Stockholder's equity	6,704	6,713
Noncontrolling Interest	142	142
Total equity	6,846	6,855
TOTAL LIABILITIES AND EQUITY	22,884	22,676
Union Electric Company
Current Assets:
Cash and cash equivalents	1	1
Accounts receivable - trade (less allowance for doubtful accounts)	202	190
Accounts receivable - affiliates	3	65
Unbilled revenue	120	146
Miscellaneous accounts and notes receivable	42	35
Materials and supplies	361	347
Current regulatory assets	158	163
Other current assets	77	92
Total current assets	964	1,039
Property and Plant, Net	10,959	10,867
Investments and Other Assets:
Nuclear decommissioning trust fund	558	549
Regulatory assets	687	695
Other assets	387	391
Total investments and other assets	1,632	1,635
TOTAL ASSETS	13,555	13,541
Current Liabilities:
Current maturities of long-term debt	380	120
Borrowings from money pool	61	0
Short-term Debt	140	97
Accounts and wages payable	182	405
Accounts payable - affiliates	59	56
Taxes accrued	69	32
Interest accrued	51	58
Current regulatory liabilities	32	18
Other current liabilities	114	117
Total current liabilities	1,088	903
Long-term Debt, Net	3,619	3,879
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes, net	2,821	2,806
Accumulated deferred investment tax credits	62	61
Regulatory liabilities	1,169	1,147
Asset retirement obligations	493	389
Pension and other postretirement benefits	277	274
Other deferred credits and liabilities	32	30
Total deferred credits and other liabilities	4,854	4,707
Commitments and Contingencies
Stockholders' Equity:
Common Stock	511	511
Other paid-in capital	1,784	1,569
Preferred stock	80	80
Retained earnings	1,619	1,892
Stockholder's equity	3,994	4,052
TOTAL LIABILITIES AND EQUITY	13,555	13,541
Ameren Illinois Company
Current Assets:
Cash and cash equivalents	0	1
Advances to money pool	33	0
Accounts receivable - trade (less allowance for doubtful accounts)	304	212
Accounts receivable - affiliates	5	22
Unbilled revenue	92	119
Miscellaneous accounts and notes receivable	12	9
Materials and supplies	88	177
Current regulatory assets	105	129
Current accumulated deferred income taxes, net	159	160
Other current assets	13	15
Total current assets	811	844
Property and Plant, Net	6,272	6,165
Investments and Other Assets:
Goodwill	411	411
Regulatory assets	883	883
Other assets	79	78
Total investments and other assets	1,373	1,372
TOTAL ASSETS	8,456	8,381
Current Liabilities:
Borrowings from money pool	0	15
Short-term Debt	0	32
Accounts and wages payable	193	207
Accounts payable - affiliates	49	50
Taxes accrued	41	17
Interest accrued	43	24
Customer deposits	76	77
Mark-to-market derivative liabilities	43	42
Current environmental remediation	46	52
Current regulatory liabilities	69	84
Other current liabilities	100	100
Total current liabilities	660	700
Long-term Debt, Net	2,241	2,241
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes, net	1,421	1,408
Regulatory liabilities	727	703
Pension and other postretirement benefits	278	277
Environmental remediation	200	199
Other deferred credits and liabilities	216	192
Total deferred credits and other liabilities	2,842	2,779
Commitments and Contingencies
Stockholders' Equity:
Common Stock	0	0
Other paid-in capital	1,980	1,980
Preferred stock	62	62
Retained earnings	664	611
Accumulated other comprehensive income (loss)	7	8
Stockholder's equity	2,713	2,661
TOTAL LIABILITIES AND EQUITY	$ 8,456	$ 8,381