Commitments And Contingencies (Tables)

12 Months Ended

Dec. 31, 2011

Commitments And Contingencies [Abstract]

Schedule Of Insurance Coverage At Callaway Energy Center


Type and Source of Coverage	Maximum Coverages			Maximum Assessments for Single Incidents
Public liability and nuclear worker liability:
American Nuclear Insurers	$	375			$ -
Pool participation		12,219	^(a)		118	^(b)
	$	12,594	^(c)		$ 118
Property damage:
Nuclear Electric Insurance Ltd.	$	2,750	^(d)		$ 23
Replacement power:
Nuclear Electric Insurance Ltd	$	490	^(e)		$ 9
Energy Risk Assurance Company	$	64	^(f)		$ -

(a)	Provided through mandatory participation in an industrywide retrospective premium assessment program.

(b)	Retrospective premium under Price-Anderson. This is subject to retrospective assessment with respect to a covered loss in excess of $375 million in the event of an incident at any licensed U.S. commercial reactor, payable at $17.5 million per year.

(c)

Limit of liability for each incident under the Price-Anderson liability provisions of the Atomic Energy Act of 1954, as amended. A company could be assessed up to $118 million per incident for each licensed reactor it operates with a maximum of $17.5 million per incident to be paid in a calendar year for each reactor. This limit is subject to change to account for the effects of inflation and changes in the number of licensed reactors.

(d)	Provides for $500 million in property damage and decontamination, excess property insurance, and premature decommissioning coverage up to $2.25 billion for losses in excess of the $500 million primary coverage.

(e)

Provides the replacement power cost insurance in the event of a prolonged accidental outage at our nuclear energy center. Weekly indemnity up to $4.5 million for 52 weeks, which commences after the first eight weeks of an outage, plus up to $3.6 million per week for a minimum of 71 weeks thereafter for a total not exceeding the policy limit of $490 million.

(f)

Provides the replacement power cost insurance in the event of a prolonged accidental outage at our nuclear energy center. The coverage commences after the first 52 weeks of insurance coverage from Nuclear Electric Insurance Ltd. and is for a weekly indemnity of $900,000 for 71 weeks in excess of the $3.6 million per week set forth above. Energy Risk Assurance Company is an affiliate and has reinsured this coverage with third-party insurance companies. See Note 14 – Related Party Transactions for more information on this affiliate transaction.

Schedule Of Lease Obligations


	Total		2012		2013		2014		2015		2016		After 5 Years
Ameren:^(a)
Capital lease payments^(b)	$	621	$	33	$	32	$	32	$	33	$	33	$	458
Less amount representing interest		312		28		27		27		27		27		176
Present value of minimum capital lease payments	$	309	$	5	$	5	$	5	$	6	$	6	$	282
Operating leases^(c)		307		38		32		26		26		25		160
Total lease obligations	$	616	$	43	$	37	$	31	$	32	$	31	$	442
Ameren Missouri:
Capital lease payments^(b)	$	621	$	33	$	32	$	32	$	33	$	33	$	458
Less amount representing interest		312		28		27		27		27		27		176
Present value of minimum capital lease payments	$	309	$	5	$	5	$	5	$	6	$	6	$	282
Operating leases^(c)		134		13		12		12		12		12		73
Total lease obligations	$	443	$	18	$	17	$	17	$	18	$	18	$	355
Ameren Illinois:
Operating leases^(c)	$	7	$	1	$	1	$	1	$	1	$	1	$	2
Genco:
Operating leases^(c)	$	131	$	11	$	11	$	11	$	10	$	11	$	77

(a)	Includes amounts for Ameren registrant and nonregistrant subsidiaries and intercompany eliminations.

(b)	See Properties under Part I, Item 2, and Note 3 – Property and Plant, Net of this report for additional information.

(c)

Amounts related to certain real estate leases and railroad licenses have indefinite payment periods. Ameren's $2 million annual obligation for these items is included in the 2012 through 2016 columns. The amounts for the indefinite payments are not included in the After 5 Years column because that period is indefinite.

Schedule Of Rental Expense


	2011		2010		2009
Ameren^(a)	$	47	$	52	$	50
Ameren Missouri		29		29		30
Ameren Illinois		17		19		19
Genco		12		13		15

(a)	Includes amounts for Ameren registrant and nonregistrant subsidiaries and intercompany eliminations.

Schedule Of Estimated Purchased Commitments


	Coal		Natural Gas		Nuclear Fuel		Purchased Power		Methane Gas		Other		Total
Ameren:^(a)
2012	$	1,120	$	398	$	36	$	196	$	1	$	221	$	1,972
2013		792		295		37		309		3		80		1,516
2014		692		220		96		125		3		75		1,211
2015		687		116		90		51		3		52		999
2016		674		39		100		52		3		62		930
Thereafter		968		134		298		746		94		246		2,486
Total	$	4,933	$	1,202	$	657	$	1,479	$	107	$	736	$	9,114
Ameren Missouri:
2012	$	623	$	63	$	36	$	19	$	1	$	78	$	820
2013		605		48		37		19		3		50		762
2014		625		36		96		19		3		47		826
2015		614		19		90		19		3		28		773
2016		644		7		100		19		3		38		811
Thereafter		921		30		298		155		94		144		1,642
Total	$	4,032	$	203	$	657	$	250	$	107	$	385	$	5,634
Ameren Illinois:
2012	$	-	$	324	$	-	$	177	$	-	$	24	$	525
2013		-		243		-		290		-		22		555
2014		-		180		-		106		-		22		308
2015		-		94		-		32		-		24		150
2016		-		31		-		33		-		24		88
Thereafter		-		105		-		591		-		102		798
Total	$	-	$	977	$	-	$	1,229	$	-	$	218	$	2,424
Genco:
2012	$	355	$	9	$	-	$	-	$	-	$	98	$	462
2013		108		4		-		-		-		5		117
2014		40		3		-		-		-		5		48
2015		45		2		-		-		-		-		47
2016		-		-		-		-		-		-		-
Thereafter		-		-		-		-		-		-		-
Total	$	548	$	18	$	-	$	-	$	-	$	108	$	674

(a)	Includes amounts for Ameren registrant and nonregistrant subsidiaries and intercompany eliminations.

Schedule Of Estimated Capital Costs To Comply With Existing And Known Emissions Related Regulations


	2012		2013 - 2016				2017 - 2021				Total
AMO^(a)	$	55	$	325 -	$	400	$	845 -	$	1,030	$	1,225 -	$	1,485
Genco		150		100 -		125		245 -		295		495 -		570
AERG		5		20 -		25		80 -		100		105 -		130
Ameren	$	210	$	445 -	$	550	$	1,170 -	$	1,425	$	1,825 -	$	2,185

(a)	Ameren Missouri's expenditures are expected to be recoverable from ratepayers.

Schedule Of Estimated Obligations For Manufactured Gas Plant Remediation


	Estimate				Recorded Liability^(a)
	Low		High		Recorded Liability^(a)
Ameren	$	107	$	183	$	107
Ameren Missouri		3		4		3
Ameren Illinois		104		179		104

(a)	Recorded liability represents the estimated minimum probable obligations, as no other amount within the range provided a better estimate.

Schedule Of Asbestos-Related Litigation Pending Lawsuits

Ameren

Missouri

Ameren

Illinois

Genco

Total^(a)

(b)

(a)	Total does not equal the sum of the subsidiary unit lawsuits because some of the lawsuits name multiple Ameren entities as defendants.

(b)	As of December 31, 2011, six asbestos-related lawsuits were pending against EEI. The general liability insurance maintained by EEI provides coverage with respect to liabilities arising from asbestos-related claims.

- Definition

The entire disclosure for environmental loss contingencies, such as presence of hazardous waste, relevant information from reports issued by regulators, and estimated costs to achieve compliance with regulatory requirements. This element may be used for all of an entity's disclosures about environmental loss contingencies.

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- Definition

The entire disclosure for lessee entity's leasing arrangements including, but not limited to, all of the following: (a.) The basis on which contingent rental payments are determined, (b.) The existence and terms of renewal or purchase options and escalation clauses, (c.) Restrictions imposed by lease agreements, such as those concerning dividends, additional debt, and further leasing.

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- Definition

Tabular disclosure of a lessee's leasing arrangements including: (1) the basis on which contingent rental payments are determined, (2) the existence and terms of renewal or purchase options and escalation clauses, (3) restrictions imposed by lease arrangements, such as those concerning dividends, additional debt, and further leasing, (4) rent holidays, rent concessions, or leasehold improvement incentives and unusual provisions or conditions. Disclosure may also include the specific period used to amortize material leasehold improvements made at the inception of the lease or during the lease term. Additionally, for operating leases having initial or remaining noncancelable lease terms in excess of one year: (a) future minimum rental payments required as of the date of the latest balance sheet presented, in the aggregate and for each of the five succeeding fiscal years, (b) the total of minimum rentals to be received in the future under noncancelable subleases as of the date of the latest balance sheet presented, and (c) for all operating leases, rental expense for each period for which an income statement is presented, with separate amounts for minimum rentals, contingent rentals, and sublease rentals. Rental payments under leases with terms of a month or less that were not renewed need not be included.

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