Commitments And Contingencies (Tables)

12 Months Ended

Dec. 31, 2016

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, 2016. The property coverage and the nuclear liability coverage renewal dates are 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	(a)	$	—
Pool participation	12,986		(b)	127		(c)
	$	13,361	(d)	$	127
Property damage:
Nuclear Electric Insurance Limited	$	2,710	(e)	$	30	(f)
European Mutual Association for Nuclear Insurance	450		(g)	—
	$	3,160		$	30
Replacement power:
Nuclear Electric Insurance Limited	$	490	(h)	$	7	(f)

(a) Effective January 1, 2017, limit was increased to $450 million.

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

(c) 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 United States commercial reactor, payable at $19 million per year.

(d) 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 $127 million per incident for each licensed reactor it operates, with a maximum of $19 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.

(e) NEIL provides $2.71 billion in property damage, decontamination, and premature decommissioning insurance for radiation events. NEIL provides $2.3 billion in property damage for nonradiation events.

(f) All NEIL-insured plants could be subject to assessments should losses exceed the accumulated funds from NEIL.

(g) European Mutual Association for Nuclear Insurance provides $450 million in excess of the $2.71 billion and $2.3 billion property coverage for radiation and nonradiation events, respectively, provided by NEIL.

(h) Provides replacement power cost insurance in the event of a prolonged accidental outage. Weekly indemnity is up to $4.5 million for 52 weeks, which commences after the first 12 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. Nonradiation events are sub-limited to $328 million.

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, 2016:

	2017		2018		2019		2020		2021		After 5 Years		Total
Ameren:(a)
Minimum capital lease payments(b)	$	33	$	32	$	32	$	32	$	32	$	297	$	458
Less amount representing interest	27		26		25		25		25		48		176
Present value of minimum capital lease payments	$	6	$	6	$	7	$	7	$	7	$	249	$	282
Operating leases(c)	13		12		12		11		10		23		81
Total lease obligations	$	19	$	18	$	19	$	18	$	17	$	272	$	363
Ameren Missouri:
Minimum capital lease payments(b)	$	33	$	32	$	32	$	32	$	32	$	297	$	458
Less amount representing interest	27		26		25		25		25		48		176
Present value of minimum capital lease payments	$	6	$	6	$	7	$	7	$	7	$	249	$	282
Operating leases(c)	11		11		11		10		9		21		73
Total lease obligations	$	17	$	17	$	18	$	17	$	16	$	270	$	355
Ameren Illinois:
Operating leases(c)	$	1	$	1	$	1	$	1	$	1	$	1	$	6

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

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

(c) Amounts related to certain land-related leases have indefinite payment periods. The annual obligations of $3 million, $2 million, and $1 million for Ameren, Ameren Missouri, and Ameren Illinois for these items are included in the 2017 through 2021 columns, respectively.

Schedule Of Rental Expense

The following table presents total rental expense included in operating expenses for the years ended December 31, 2016, 2015, and 2014:

	2016		2015		2014
Ameren(a)	$	38	$	36	$	37
Ameren Missouri	34		34		32
Ameren Illinois	30		28		25

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

Schedule Of Estimated Purchased Commitments

December 31, 2016. Ameren’s and Ameren Missouri’s purchased power commitments include a 102-megawatt power purchase agreement with a wind farm operator, which expires in 2024. Ameren’s and Ameren Illinois’ purchased power commitments 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, 2016.

	Coal		Natural Gas(a)		Nuclear Fuel		Purchased Power(b)		Methane Gas		Other		Total
Ameren:(c)
2017	$	599	$	238	$	45	$	255	$	3	$	118	$	1,258
2018	371		167		70		156		4		60		828
2019	311		99		27		79		4		60		580
2020	27		45		38		58		5		56		229
2021	—		12		44		58		5		29		148
Thereafter	—		43		45		478		65		198		829
Total	$	1,308	$	604	$	269	$	1,084	$	86	$	521	$	3,872
Ameren Missouri:
2017	$	599	$	43	$	45	$	22	$	3	$	39	$	751
2018	371		29		70		22		4		29		525
2019	311		15		27		22		4		29		408
2020	27		10		38		22		5		29		131
2021	—		5		44		22		5		28		104
Thereafter	—		18		45		59		65		183		370
Total	$	1,308	$	120	$	269	$	169	$	86	$	337	$	2,289
Ameren Illinois:
2017	$	—	$	195	$	—	$	233	$	—	$	36	$	464
2018	—		138		—		134		—		24		296
2019	—		83		—		57		—		27		167
2020	—		35		—		36		—		27		98
2021	—		8		—		36		—		—		44
Thereafter	—		25		—		419		—		—		444
Total	$	—	$	484	$	—	$	915	$	—	$	114	$	1,513

(a) Includes amounts for generation and for distribution.

(b) The purchased power amounts for Ameren and Ameren Illinois include agreements through 2032 for renewable energy credits 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.

(c) Includes amounts for Ameren registrant and nonregistrant subsidiaries.