Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2020

Schedule Of Fair Value Hierarchy Of Assets And Liabilities Measured At Fair Value On Recurring Basis

The following table sets forth, by level within the fair value hierarchy, our assets and liabilities measured at fair value on a recurring basis as of December 31, 2020 and 2019:


		December 31, 2020									December 31, 2019
		Level 1		Level 2		Level 3		Total			Level 1		Level 2		Level 3		Total
Assets:
Ameren Missouri
	Derivative assets – commodity contracts:
	Fuel oils	$	—	$	—	$	2	$	2		$	—	$	—	$	6	$	6
	Natural gas	—		3		—		3			—		—		—		—
	Power	2		—		5		7			—		2		14		16

	Total derivative assets – commodity contracts	$	2	$	3	$	7	$	12		$	—	$	2	$	20	$	22
	Nuclear decommissioning trust fund:

	Equity securities:
	U.S. large capitalization	$	680	$	—	$	—	$	680		$	569	$	—	$	—	$	569
	Debt securities:
	U.S. Treasury and agency securities	—		115		—		115			—		107		—		107
	Corporate bonds	—		115		—		115			—		93		—		93


	Other	—		67		—		67			—		73		—		73
	Total nuclear decommissioning trust fund	$	680	$	297	$	—	$	977	(a)	$	569	$	273	$	—	$	842	(a)
	Total Ameren Missouri	$	682	$	300	$	7	$	989		$	569	$	275	$	20	$	864
Ameren Illinois
	Derivative assets – commodity contracts:
	Natural gas	$	—	$	6	$	4	$	10		$	—	$	1	$	3	$	4


Ameren
	Derivative assets – commodity contracts(b)	$	2	$	9	$	11	$	22		$	—	$	3	$	23	$	26
	Nuclear decommissioning trust fund(c)	680		297		—		977		(a)	569		273		—		842		(a)
	Total Ameren	$	682	$	306	$	11	$	999		$	569	$	276	$	23	$	868
Liabilities:
Ameren Missouri
	Derivative liabilities – commodity contracts:
	Fuel oils	$	6	$	—	$	3	$	9		$	1	$	—	$	6	$	7
	Natural gas	—		1		—		1			—		2		—		2
	Power	8		—		3		11			—		2		1		3
	Uranium	—		—		—		—			—		—		1		1
	Total Ameren Missouri	$	14	$	1	$	6	$	21		$	1	$	4	$	8	$	13
Ameren Illinois
	Derivative liabilities – commodity contracts:
	Natural gas	$	—	$	1	$	1	$	2		$	3	$	12	$	3	$	18
	Power	—		—		198		198			—		—		224		224
	Total Ameren Illinois	$	—	$	1	$	199	$	200		$	3	$	12	$	227	$	242
Ameren
	Derivative liabilities – commodity contracts(b)	$	14	$	2	$	205	$	221		$	4	$	16	$	235	$	255

(a)Balance excludes $5 million and $5 million of cash and cash equivalents, receivables, payables, and accrued income, net for December 31, 2020 and 2019, respectively.

(b)See the Ameren Missouri and Ameren Illinois sections of the table for a breakout of the fair value of Ameren’s derivative assets and liabilities by type of commodity.

(c)See the Ameren Missouri section of the table for a breakout of Ameren’s nuclear decommissioning trust fund by investment type.

Schedule Of Changes In The Fair Value Of Financial Assets And Liabilities Classified As Level 3 In The Fair Value Hierarchy

The following table presents the fair value reconciliation of Level 3 power derivative contract assets and liabilities measured at fair value on a recurring basis for the years ended December 31, 2020 and 2019:


	2020						2019
	Ameren Missouri		Ameren Illinois		Ameren		Ameren Missouri		Ameren Illinois		Ameren





















Beginning balance at January 1	$	13	$	(224)	$	(211)	$	—	$	(183)	$	(183)
Realized and unrealized gains (losses) included in regulatory assets/liabilities	15		8		23		23		(56)		(33)


Settlements	(26)		18		(8)		(7)		15		8

Transfers out of Level 3	—		—		—		(3)		—		(3)
Ending balance at December 31	$	2	$	(198)	$	(196)	$	13	$	(224)	$	(211)
Change in unrealized gains (losses) related to assets/liabilities held at December 31	$	1	$	9	$	10	$	12	$	(54)	$	(42)

Fair Value Inputs, Assets and Liabilities, Quantitative Information

The following table describes the valuation techniques and significant unobservable inputs utilized for the fair value of our Level 3 power derivative contract assets and liabilities as of December 31, 2020 and 2019:


		Fair Value							Weighted Average(b)
	Commodity	Assets		Liabilities		Valuation Technique(s)	Unobservable Input(a)	Range









2020	Power(c)	$	5	$	(201)	Discounted cash flow	Average forward peak and off-peak pricing – forwards/swaps ($/MWh)	23 – 37	29

							Nodal basis ($/MWh)	(6) – 0	(2)


							Trend rate (%)	2 – 6	3











































2019	Power(d)	$	14	$	(225)	Discounted cash flow	Average forward peak and off-peak pricing – forwards/swaps ($/MWh)	22 – 34	25
							Nodal basis ($/MWh)	(6) – 0	(2)


							Trend rate (%)	(1) – 0	0

(a)Generally, significant increases (decreases) in these inputs in isolation would result in a significantly higher (lower) fair value measurement.

(b)Unobservable inputs were weighted by relative fair value.

(c)Valuations through 2029 use visible forward prices adjusted for nodal-to-hub basis differentials. Valuations beyond 2029 use a trend rate factor and are similarly adjusted for nodal-to-hub basis differentials.

(d)Valuations through 2028 use visible forward prices adjusted for nodal-to-hub basis differentials. Valuations beyond 2028 use a trend rate factor and are similarly adjusted for nodal-to-hub basis differentials.

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]

The following table sets forth, by level within the fair value hierarchy, the carrying amount and fair value of financial assets and liabilities disclosed, but not carried, at fair value as of December 31, 2020 and 2019:


	Carrying Amount			Fair Value
				Level 1		Level 2		Level 3			Total
Ameren:	December 31, 2020
Cash, cash equivalents, and restricted cash	$	301		$	301	$	—	$	—		$	301
Investments in industrial development revenue bonds(a)	256			—		256		—			256
Short-term debt	490			—		490		—			490
Long-term debt (including current portion)(a)	11,086		(b)	—		12,778		537		(c)	13,315
Ameren Missouri:
Cash, cash equivalents, and restricted cash	$	145		$	145	$	—	$	—		$	145
Advances to money pool	139			—		139		—			139
Investments in industrial development revenue bonds(a)	256			—		256		—			256


Long-term debt (including current portion)(a)	5,104		(b)	—		6,160		—			6,160
Ameren Illinois:
Cash, cash equivalents, and restricted cash	$	147		$	147	$	—	$	—		$	147


Borrowings from money pool	19			—		19		—			19
Long-term debt (including current portion)	3,946		(b)	—		4,822		—			4,822
	December 31, 2019
Ameren:
Cash, cash equivalents, and restricted cash	$	176		$	176	$	—	$	—		$	176
Investments in industrial development revenue bonds(a)	263			—		263		—			263
Short-term debt	440			—		440		—			440
Long-term debt (including current portion)(a)	9,357		(b)	—		9,957		484		(c)	10,441
Ameren Missouri:
Cash, cash equivalents, and restricted cash	$	39		$	39	$	—	$	—		$	39

Investments in industrial development revenue bonds(a)	263			—		263		—			263
Short-term debt	234			—		234		—			234

Long-term debt (including current portion)(a)	4,190		(b)	—		4,772		—			4,772
Ameren Illinois:
Cash, cash equivalents, and restricted cash	$	125		$	125	$	—	$	—		$	125

Short-term debt	53			—		53		—			53

Long-term debt (including current portion)	3,575		(b)	—		4,019		—			4,019

(a)Ameren and Ameren Missouri have investments in industrial development revenue bonds, classified as held-to-maturity and recorded in “Other Assets,” that are equal to the finance obligations for the Peno Creek and Audrain CT energy centers. As of December 31, 2020 and 2019, the carrying amount of both the investments in industrial development revenue bonds and the finance obligations approximated fair value.

(b)Included unamortized debt issuance costs, which were excluded from the fair value measurement, of $84 million, $36 million, and $36 million for Ameren, Ameren Missouri, and Ameren Illinois, respectively, as of December 31, 2020. Included unamortized debt issuance costs, which were excluded from the fair value measurement, of $72 million, $30 million, and $34 million for Ameren, Ameren Missouri, and Ameren Illinois, respectively, as of December 31, 2019.

(c)The Level 3 fair value amount consists of ATXI’s senior unsecured notes.