Commitments And Contingencies (Tables)

12 Months Ended

Dec. 31, 2012

Commitments and Contingencies Disclosure [Abstract]

Schedule Of Insurance Coverage At Callaway Energy Center

The following table presents insurance coverage at Ameren Missouri’s Callaway energy center at December 31, 2012. The property coverage and the nuclear liability coverage must be renewed on April 1 and January 1, respectively, of each year.



Type and Source of Coverage	Maximum Coverages			Maximum Assessments
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	^(e)
Replacement power:
Nuclear Electric Insurance Ltd	$	490	^(f)	$	9	^(e)
Energy Risk Assurance Company	$	64	^(g)	$	—


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


(b)	Retrospective premium under the Price-Anderson Act. 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 Act 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)	All Nuclear Electric Insurance Ltd. insured plants could be subject to assessments should losses exceed the accumulated funds from Nuclear Electric Insurance Ltd.


(f)	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.

(g)

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

We lease various facilities, office equipment, plant equipment, and rail cars under capital and operating leases. The following table presents our lease obligations at December 31, 2012:



	Total		2013		2014		2015		2016		2017		After 5 Years
Ameren:^(a)
Capital lease payments^(b)	$	588	$	32	$	32	$	33	$	33	$	33	$	425
Less amount representing interest	284		27		27		27		27		27		149
Present value of minimum capital lease payments	$	304	$	5	$	5	$	6	$	6	$	6	$	276
Operating leases^(c)	272		31		27		26		26		25		137
Total lease obligations	$	576	$	36	$	32	$	32	$	32	$	31	$	413
Ameren Missouri:
Capital lease payments^(b)	$	588	$	32	$	32	$	33	$	33	$	33	$	425
Less amount representing interest	284		27		27		27		27		27		149
Present value of minimum capital lease payments	$	304	$	5	$	5	$	6	$	6	$	6	$	276
Operating leases^(c)	123		12		12		12		12		13		62
Total lease obligations	$	427	$	17	$	17	$	18	$	18	$	19	$	338
Ameren Illinois:
Operating leases^(c)	$	7	$	1	$	1	$	1	$	1	$	1	$	2


(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 land-related leases have indefinite payment periods. The annual obligation of $2 million, $1 million and $1 million for Ameren, Ameren Missouri and Ameren Illinois for these items is included in the 2013 through 2017 columns, respectively.

Schedule Of Rental Expense

The following table presents total rental expense, included in operating expenses, for the years ended December 31, 2012, 2011, and 2010:



	2012		2011		2010
Ameren^(a)	$	48	$	47	$	52
Ameren Missouri	29		29		29
Ameren Illinois	19		17		19


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

Schedule Of Estimated Purchased Commitments

The table below presents our estimated fuel, purchased power, and other commitments at December 31, 2012. Ameren’s and Ameren Missouri’s purchased power obligations include a 102-megawatt power purchase agreement with a wind farm operator that expires in 2024. Ameren’s and Ameren Illinois’ purchased power obligations include the Ameren Illinois power purchase agreements entered into as part of the IPA-administered power procurement process. Included in the Other column are minimum purchase commitments under contracts for equipment, design and construction, and meter reading services at December 31, 2012. Ameren's and Ameren Illinois' Other column also include obligations related to IEIMA. In addition, the Other column includes Ameren's and Ameren Missouri's obligations related to energy efficiency programs under the MEEIA as approved by the MoPSC's December 2012 electric rate order. The order provides that, beginning in 2013, Ameren Missouri will invest approximately $147 million over three years for energy efficiency programs. See Note 2 - Rate and Regulatory Matters for additional information about the IEIMA and MEEIA.



	Coal		Natural Gas		Nuclear Fuel		Purchased Power^(a)		Methane Gas		Other		Total
Ameren:^(b)
2013	$	908	$	349	$	36	$	421	$	3	$	174	$	1,891
2014	774		254		89		309		3		167		1,596
2015	702		138		87		164		4		117		1,212
2016	732		54		95		78		4		62		1,025
2017	701		34		78		55		5		50		923
Thereafter	277		105		277		687		99		246		1,691
Total	$	4,094	$	934	$	662	$	1,714	$	118	$	816	$	8,338
Ameren Missouri:
2013	$	620	$	57	$	36	$	19	$	3	$	106	$	841
2014	625		43		89		19		3		123		902
2015	614		25		87		19		4		87		836
2016	644		10		95		19		4		38		810
2017	676		5		78		19		5		26		809
Thereafter	245		28		277		130		99		144		923
Total	$	3,424	$	168	$	662	$	225	$	118	$	524	$	5,121
Ameren Illinois:
2013	$	—	$	270	$	—	$	401	$	—	$	24	$	695
2014	—		206		—		289		—		22		517
2015	—		110		—		145		—		24		279
2016	—		44		—		59		—		24		127
2017	—		29		—		36		—		24		89
Thereafter	—		78		—		559		—		102		739
Total	$	—	$	737	$	—	$	1,489	$	—	$	220	$	2,446

(a)

The purchased power amounts for Ameren and Ameren Illinois includes 20-year agreements for renewable energy credits that were entered into in December 2010 with various renewable energy suppliers. The agreements contain a provision that allows Ameren Illinois to reduce the quantity purchased in the event that Ameren Illinois would not be able to recover the costs associated with the renewable energy credits.


(b)	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



	2013		2014 - 2017					2018 - 2022					Total
AMO^(a)	$	105	$	215	-	$	260	$	795	-	$	975	$	1,115	-	$	1,340
Genco	30		100		-	125		220		-	270		350		-	425
AERG	5		20		-	25		20		-	25		45		-	55
Ameren	$	140	$	335	-	$	410	$	1,035	-	$	1,270	$	1,510	-	$	1,820


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

Schedule Of Estimated Obligations For Manufactured Gas Plant Remediation

The following table presents, as of December 31, 2012, the estimated probable obligation to remediate these former MGP sites.



	Estimate				Recorded Liability^(a)
	Low		High		Recorded Liability^(a)
Ameren	$	257	$	339	$	257
Ameren Missouri	5		6		5
Ameren Illinois	252		333		252


(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

The following table presents the pending asbestos-related lawsuits filed against the Ameren Companies as of December 31, 2012:


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

- 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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Ameren
Missouri

Ameren
Illinois