Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2017

Fair Value Disclosures [Abstract]

Fair Value, Assets and Liabilities Measured on Nonrecurring Basis, Valuation Techniques

The following table describes the valuation techniques and unobservable inputs utilized by the Ameren Companies for the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy for the periods ended June 30, 2017 and December 31, 2016:

		Fair Value								Weighted Average
		Assets		Liabilities			Valuation Technique(s)	Unobservable Input	Range
Level 3 Derivative asset and liability – commodity contracts(a):
2017
	Fuel oils	$	1	$	(2	)	Option model	Volatilities(%)(b)	26 – 36	27
							Discounted cash flow	Counterparty credit risk(%)(c)(d)	0.22	(e)
								Ameren Missouri credit risk(%)(c)(d)	0.37	(e)
								Escalation rate (%)(b)(f)	0 – 1	0
	Natural gas	—		(2		)	Discounted cash flow	Nodal basis ($/mmbtu)(b)	(0.80) – (0.10)	(0.70)
								Counterparty credit risk (%)(c)(d)	0.45 – 6	0.82
								Ameren Illinois credit risk (%)(c)(d)	0.37	(e)

		Fair Value								Weighted Average
		Assets		Liabilities			Valuation Technique(s)	Unobservable Input	Range
	Power(g)	$	15	$	(193	)	Discounted cash flow	Average forward peak and off-peak pricing – forwards/swaps ($/MWh)(h)	25 – 42	29
								Estimated auction price for FTRs ($/MW)(b)	(730) – 1,398	284
								Nodal basis ($/MWh)(h)	(3) – 0	(2)
								Ameren Illinois credit risk (%)(c)(d)	0.37	(e)
							Fundamental energy production model	Estimated future natural gas prices ($/mmbtu)(b)	3 – 4	3
								Escalation rate (%)(b)(i)	3	(e)
							Contract price allocation	Estimated renewable energy credit costs ($/credit)(b)	5 – 7	6
2016
	Fuel oils	$	1	$	—		Option model	Volatilities (%)(b)	24 – 66	28
							Discounted cash flow	Counterparty credit risk (%)(c)(d)	0.13 – 0.22	0.15
								Ameren Missouri credit risk (%)(c)(d)	0.38	(e)
								Escalation rate (%)(b)(f)	(2) – 2	0
	Natural gas	1		(1		)	Option model	Volatilities (%)(b)	31 – 66	36
								Nodal basis ($/mmbtu)(b)	(0.40) – (0.10)	(0.20)
							Discounted cash flow	Nodal basis ($/mmbtu)(b)	(0.80) – 0	(0.50)
								Counterparty credit risk (%)(c)(d)	0.13 – 8	1
								Ameren Illinois credit risk (%)(c)(d)	0.38	(e)
	Power(g)	9		(187		)	Discounted cash flow	Average forward peak and off-peak pricing – forwards/swaps ($/MWh)(h)	26 – 44	29
								Estimated auction price for FTRs ($/MW)(b)	(71) – 5,270	125
								Nodal basis ($/MWh)(h)	(6) – 0	(2)
								Ameren Illinois credit risk (%)(c)(d)	0.38	(e)
							Fundamental energy production model	Estimated future natural gas prices ($/mmbtu)(b)	3 – 4	3
								Escalation rate (%)(b)(i)	5	(e)
							Contract price allocation	Estimated renewable energy credit costs ($/credit)(b)	5 – 7	6
	Uranium	—		(4		)	Option model	Volatilities (%)(b)	24	(e)
							Discounted cash flow	Average forward uranium pricing ($/pound)(b)	22 – 24	22
								Ameren Missouri credit risk (%)(c)(d)	0.38	(e)

(a) The derivative asset and liability balances are presented net of counterparty credit considerations.

(b) Generally, significant increases (decreases) in this input in isolation would result in a significantly higher (lower) fair value measurement.

(c) Generally, significant increases (decreases) in this input in isolation would result in a significantly lower (higher) fair value measurement.

(d) Counterparty credit risk is applied only to counterparties with derivative asset balances. Ameren Missouri and Ameren Illinois credit risk is applied only to counterparties with derivative liability balances.

(e) Not applicable.

(f) Escalation rate applies to fuel oil prices 2019 and beyond.

(g) Power valuations use visible third-party pricing evaluated by month for peak and off-peak demand through 2021 for June 30, 2017 and through 2020 for December 31, 2016. Valuations beyond 2021 for June 30, 2017 and 2020 for December 31, 2016 use fundamentally modeled pricing by month for peak and off-peak demand.

(h) The balance at Ameren is comprised of Ameren Missouri and Ameren Illinois power contracts, which respond differently to unobservable input changes due to their opposing positions.

(i) Escalation rate applies to power prices in 2031 and beyond.

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 June 30, 2017:

		Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1)		Significant Other Observable  Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)		Total
Assets:
Ameren	Derivative assets – commodity contracts(a):
	Fuel oils	$	—	$	—	$	1	$	1
	Natural gas	1		1		—		2
	Power	—		—		15		15
	Total derivative assets – commodity contracts	$	1	$	1	$	16	$	18
	Nuclear decommissioning trust fund:
	Cash and cash equivalents	$	2	$	—	$	—	$	2
	Equity securities:
	U.S. large capitalization	426		—		—		426
	Debt securities:
	U.S. treasury and agency securities	—		115		—		115
	Corporate bonds	—		83		—		83
	Other	—		23		—		23
	Total nuclear decommissioning trust fund	$	428	$	221	$	—	$	649	(b)
	Total Ameren	$	429	$	222	$	16	$	667
Ameren Missouri	Derivative assets – commodity contracts(a):
	Fuel oils	$	—	$	—	$	1	$	1
	Power	—		—		15		15
	Total derivative assets – commodity contracts	$	—	$	—	$	16	$	16
	Nuclear decommissioning trust fund:
	Cash and cash equivalents	$	2	$	—	$	—	$	2
	Equity securities:
	U.S. large capitalization	426		—		—		426
	Debt securities:
	U.S. treasury and agency securities	—		115		—		115
	Corporate bonds	—		83		—		83
	Other	—		23		—		23
	Total nuclear decommissioning trust fund	$	428	$	221	$	—	$	649	(b)
	Total Ameren Missouri	$	428	$	221	$	16	$	665
Ameren Illinois	Derivative assets – commodity contracts(a):
	Natural gas	$	1	$	1	$	—	$	2
Liabilities:
Ameren	Derivative liabilities – commodity contracts(a):
	Fuel oils	$	4	$	—	$	2	$	6
	Natural gas	—		20		2		22
	Power	—		—		193		193
	Total Ameren	$	4	$	20	$	197	$	221
Ameren Missouri	Derivative liabilities – commodity contracts(a):
	Fuel oils	$	4	$	—	$	2	$	6
	Natural gas	—		7		—		7
	Power	—		—		1		1
	Total Ameren Missouri	$	4	$	7	$	3	$	14
Ameren Illinois	Derivative liabilities – commodity contracts(a):
	Natural gas	$	—	$	13	$	2	$	15
	Power	—		—		192		192
	Total Ameren Illinois	$	—	$	13	$	194	$	207

(a) The derivative asset and liability balances are presented net of counterparty credit considerations.

(b) Balance excludes $2 million of receivables, payables, and accrued income, net.

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, 2016:

		Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1)		Significant Other Observable  Inputs (Level 2)		Significant Other Unobservable Inputs (Level 3)		Total
Assets:
Ameren	Derivative assets – commodity contracts(a):
	Fuel oils	$	2	$	—	$	1	$	3
	Natural gas	2		12		1		15
	Power	—		—		9		9
	Total derivative assets – commodity contracts	$	4	$	12	$	11	$	27
	Nuclear decommissioning trust fund:
	Cash and cash equivalents	$	1	$	—	$	—	$	1
	Equity securities:
	U.S. large capitalization	408		—		—		408
	Debt securities:
	U.S. treasury and agency securities	—		112		—		112
	Corporate bonds	—		67		—		67
	Other	—		17		—		17
	Total nuclear decommissioning trust fund	$	409	$	196	$	—	$	605	(b)
	Total Ameren	$	413	$	208	$	11	$	632
Ameren Missouri	Derivative assets – commodity contracts(a):
	Fuel oils	$	2	$	—	$	1	$	3
	Natural gas	—		1		1		2
	Power	—		—		9		9
	Total derivative assets – commodity contracts	$	2	$	1	$	11	$	14
	Nuclear decommissioning trust fund:
	Cash and cash equivalents	$	1	$	—	$	—	$	1
	Equity securities:
	U.S. large capitalization	408		—		—		408
	Debt securities:
	U.S. treasury and agency securities	—		112		—		112
	Corporate bonds	—		67		—		67
	Other	—		17		—		17
	Total nuclear decommissioning trust fund	$	409	$	196	$	—	$	605	(b)
	Total Ameren Missouri	$	411	$	197	$	11	$	619
Ameren Illinois	Derivative assets – commodity contracts(a):
	Natural gas	$	2	$	11	$	—	$	13
Liabilities:
Ameren	Derivative liabilities – commodity contracts(a):
	Fuel oils	$	5	$	—	$	—	$	5
	Natural gas	—		13		1		14
	Power	—		1		187		188
	Uranium	—		—		4		4
	Total Ameren	$	5	$	14	$	192	$	211
Ameren Missouri	Derivative liabilities – commodity contracts(a):
	Fuel oils	$	5	$	—	$	—	$	5
	Natural gas	—		6		—		6
	Power	—		1		2		3
	Uranium	—		—		4		4
	Total Ameren Missouri	$	5	$	7	$	6	$	18
Ameren Illinois	Derivative liabilities – commodity contracts(a):
	Natural gas	$	—	$	7	$	1	$	8
	Power	—		—		185		185
	Total Ameren Illinois	$	—	$	7	$	186	$	193

(a) The derivative asset and liability balances are presented net of counterparty credit considerations.

(b) Balance excludes $2 million of receivables, payables, and accrued income, net.

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

The following table summarizes the changes in the fair value of power financial assets and liabilities classified as Level 3 in the fair value hierarchy:

		Net derivative commodity contracts
		Ameren Missouri			Ameren Illinois			Ameren
For the three months ended June 30, 2017
Beginning balance at April 1, 2017	$	4		$	(194	)	$	(190	)
Realized and unrealized gains (losses) included in regulatory assets/liabilities		(1	)		(1	)		(2	)
Purchases		15			—			15
Settlements		(4	)		3			(1	)
Ending balance at June 30, 2017	$	14		$	(192	)	$	(178	)
Change in unrealized gains (losses) related to assets/liabilities held at June 30, 2017	$	—		$	(2	)	$	(2	)
For the three months ended June 30, 2016
Beginning balance at April 1, 2016	$	6		$	(187	)	$	(181	)
Realized and unrealized gains (losses) included in regulatory assets/liabilities		(1	)		14			13
Purchases		13			—			13
Settlements		(4	)		4			—
Ending balance at June 30, 2016	$	14		$	(169	)	$	(155	)
Change in unrealized gains (losses) related to assets/liabilities held at June 30, 2016	$	—		$	14		$	14
For the six months ended June 30, 2017
Beginning balance at January 1, 2017	$	7		$	(185	)	$	(178	)
Realized and unrealized gains (losses) included in regulatory assets/liabilities		(1	)		(11	)		(12	)
Purchases		15			—			15
Settlements		(7	)		4			(3	)
Ending balance at June 30, 2017	$	14		$	(192	)	$	(178	)
Change in unrealized gains (losses) related to assets/liabilities held at June 30, 2017	$	—		$	(13	)	$	(13	)
For the six months ended June 30, 2016
Beginning balance at January 1, 2016	$	16		$	(170	)	$	(154	)
Realized and unrealized gains (losses) included in regulatory assets/liabilities		(4	)		(7	)		(11	)
Purchases		13			—			13
Settlements		(11	)		8			(3	)
Ending balance at June 30, 2016	$	14		$	(169	)	$	(155	)
Change in unrealized gains (losses) related to assets/liabilities held at June 30, 2016	$	—		$	(5	)	$	(5	)

Schedule Of Carrying Amounts And Estimated Fair Values Of Long-Term Debt, Capital Lease Obligations And Preferred Stock

The following table presents the carrying amounts and estimated fair values of our long-term debt, capital lease obligations and preferred stock at June 30, 2017, and December 31, 2016:

	June 30, 2017				December 31, 2016
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Ameren:
Long-term debt and capital lease obligations (including current portion)	$	7,399	$	7,942	$	7,276	$	7,772
Preferred stock(a)	142		131		142		131
Ameren Missouri:
Long-term debt and capital lease obligations (including current portion)	$	3,966	$	4,310	$	3,994	$	4,304
Preferred stock	80		79		80		79
Ameren Illinois:
Long-term debt (including current portion)	$	2,589	$	2,773	$	2,588	$	2,765
Preferred stock	62		52		62		52

(a) Preferred stock is recorded in “Noncontrolling Interests” on the consolidated balance sheet.