Commitments And Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

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, 2017:

	2018		2019		2020		2021		2022		After 5 Years		Total
Ameren:(a)
Minimum capital lease payments(b)(c)	$	32	$	32	$	32	$	33	$	32	$	264	$	425
Less amount representing interest	26		25		25		25		24		24		149
Present value of minimum capital lease payments	$	6	$	7	$	7	$	8	$	8	$	240	$	276
Operating leases	10		9		8		6		6		14		53
Total lease obligations	$	16	$	16	$	15	$	14	$	14	$	254	$	329
Ameren Missouri:
Minimum capital lease payments(b)(c)	$	32	$	32	$	32	$	33	$	32	$	264	$	425
Less amount representing interest	26		25		25		25		24		24		149
Present value of minimum capital lease payments	$	6	$	7	$	7	$	8	$	8	$	240	$	276
Operating leases	8		8		7		6		6		14		49
Total lease obligations	$	14	$	15	$	14	$	14	$	14	$	254	$	325
Ameren Illinois:
Operating leases	$	1	(d)		(d)		(d)		(d)		$	1	$	2

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

(b) See Note 3 – Property, Plant, and Equipment, Net for additional information.

(c) See Note 5 – Long-term Debt and Equity Financings for additional information on Ameren’s and Ameren Missouri’s capital lease agreements.

(d) Less than $1 million.

Schedule Of Rental Expense

The following table presents total operating lease expenses included in “Operating Expenses” in the statement of income for the years ended December 31, 2017, 2016, and 2015:

	2017		2016		2015
Ameren(a)	$	11	$	38	$	36
Ameren Missouri	10		34		34
Ameren Illinois	1		30		28

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

Schedule Of Estimated Purchased Commitments

The table below presents our estimated minimum fuel, purchased power, and other commitments at December 31, 2017. Ameren’s and Ameren Illinois’ purchased power commitments include the Ameren Illinois 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, among other agreements, at December 31, 2017.

	Coal		Natural Gas(a)		Nuclear Fuel		Purchased Power(b)(c)		Methane Gas		Other		Total
Ameren:(d)
2018	$	463	$	205	$	67	$	170	$	3	$	73	$	981
2019	383		163		26		63		4		37		676
2020	85		110		39		14		4		36		288
2021	27		46		45		3		5		25		151
2022	—		11		12		2		5		25		55
Thereafter	—		38		45		18		58		95		254
Total	$	958	$	573	$	234	$	270	$	79	$	291	$	2,405
Ameren Missouri:
2018	$	463	$	42	$	67	$	—	$	3	$	53	$	628
2019	383		36		26		—		4		24		473
2020	85		29		39		—		4		24		181
2021	27		13		45		—		5		25		115
2022	—		6		12		—		5		25		48
Thereafter	—		16		45		—		58		75		194
Total	$	958	$	142	$	234	$	—	$	79	$	226	$	1,639
Ameren Illinois:
2018	$	—	$	163	$	—	$	170	$	—	$	19	$	352
2019	—		127		—		63		—		13		203
2020	—		81		—		14		—		12		107
2021	—		33		—		3		—		—		36
2022	—		5		—		2		—		—		7
Thereafter	—		22		—		18		—		—		40
Total	$	—	$	431	$	—	$	270	$	—	$	44	$	745

(a) Includes amounts for generation and for distribution.

(b) The purchased power amounts for Ameren and Ameren Illinois exclude agreements for renewable energy credits through 2032 with various renewable energy suppliers due to the contingent nature of the payment amounts.

(c) The purchased power amounts for Ameren and Ameren Missouri exclude a 102-megawatt power purchase agreement with a wind farm operator, which expires in 2024, due to the contingent nature of the payment amounts.

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