Derivative Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2015

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Open Gross Derivative Volumes By Commodity Type

The following table presents open gross commodity contract volumes by commodity type for derivative assets and liabilities as of September 30, 2015, and December 31, 2014. As of September 30, 2015, these contracts ran through October 2017, March 2021, May 2032, and December 2016 for fuel oils, natural gas, power, and uranium, respectively.

	Quantity (in millions, except as indicated)
	2015			2014
Commodity	Ameren Missouri	Ameren Illinois	Ameren	Ameren Missouri	Ameren Illinois	Ameren
Fuel oils (in gallons)(a)	33	(b)	33	50	(b)	50
Natural gas (in mmbtu)	30	152	182	28	108	136
Power (in megawatthours)	1	10	11	1	11	12
Uranium (pounds in thousands)	299	(b)	299	332	(b)	332

(a) Fuel oils consist of heating oil and ultra-low-sulfur diesel.

(b) Not applicable.

Derivative Instruments Carrying Value

The following table presents the carrying value and balance sheet location of all derivative instruments, none of which were designated as hedging instruments under hedge accounting, as of September 30, 2015, and December 31, 2014:

	Balance Sheet Location	Ameren Missouri		Ameren Illinois		Ameren
2015
Natural gas	Other current assets	$	1	$	—	$	1
Power	Other current assets	22		—		22
	Other assets	1		—		1
	Total assets	$	24	$	—	$	24
Fuel oils	Other current liabilities	$	19	$	—	$	19
	Other deferred credits and liabilities	6		—		6
Natural gas	MTM derivative liabilities	(a)		26		(a)
	Other current liabilities	5		—		31
	Other deferred credits and liabilities	9		18		27
Power	MTM derivative liabilities	(a)		12		(a)
	Other current liabilities	1		—		13
	Other deferred credits and liabilities	—		158		158
Uranium	Other current liabilities	1		—		1
	Total liabilities	$	41	$	214	$	255
2014
Fuel oils	Other current assets	$	2	$	—	$	2
Natural gas	Other current assets	1		1		2
Power	Other current assets	15		—		15
	Total assets	$	18	$	1	$	19
Fuel oils	Other current liabilities	$	22	$	—	$	22
	Other deferred credits and liabilities	7		—		7
Natural gas	MTM derivative liabilities	(a)		31		(a)
	Other current liabilities	6		—		37
	Other deferred credits and liabilities	6		13		19
Power	MTM derivative liabilities	(a)		11		(a)
	Other current liabilities	3		—		14
	Other deferred credits and liabilities	—		131		131
Uranium	Other current liabilities	2		—		2
	Total liabilities	$	46	$	186	$	232

(a) Balance sheet line item not applicable to registrant.

Cumulative Pretax Net Gains (Losses) On All Derivative Instruments In OCI

The following table presents the cumulative amount of pretax net gains (losses) on all derivative instruments deferred in regulatory assets or regulatory liabilities as of September 30, 2015, and December 31, 2014:

	Ameren Missouri			Ameren Illinois			Ameren
2015
Fuel oils derivative contracts(a)	$	(25	)	$	—		$	(25	)
Natural gas derivative contracts(b)	(13		)	(44		)	(57		)
Power derivative contracts(c)	22			(170		)	(148		)
Uranium derivative contracts(d)	(1		)	—			(1		)
2014
Fuel oils derivative contracts	$	(29	)	$	—		$	(29	)
Natural gas derivative contracts	(11		)	(43		)	(54		)
Power derivative contracts	12			(142		)	(130		)
Uranium derivative contracts	(2		)	—			(2		)

(a) Represents net losses associated with fuel oils derivative contracts at Ameren Missouri. These contracts are a partial hedge of Ameren Missouri’s rail transportation surcharges for coal through December 2017. Losses deferred as current regulatory assets include $19 million at Ameren and Ameren Missouri.

(b) Represents net losses associated with natural gas derivative contracts. These contracts are a partial hedge of natural gas requirements through March 2021 at Ameren and Ameren Missouri and through October 2019 at Ameren Illinois. Gains deferred as current regulatory liabilities include $1 million at Ameren and Ameren Missouri. Losses deferred as current regulatory assets include $31 million, $5 million, and $26 million at Ameren, Ameren Missouri, and Ameren Illinois, respectively.

(c) Represents net gains (losses) associated with power derivative contracts. These contracts are a partial hedge of power price requirements through May 2032 at Ameren and Ameren Illinois and through December 2016 at Ameren Missouri. Gains deferred as current regulatory liabilities include $22 million at Ameren and Ameren Missouri. Losses deferred as current regulatory assets include $13 million, $1 million, and $12 million at Ameren, Ameren Missouri, and Ameren Illinois, respectively.

(d) Represents net losses on uranium derivative contracts at Ameren Missouri. These contracts are a partial hedge of Ameren Missouri’s uranium requirements through January 2017. Losses deferred as current regulatory assets include $1 million at Ameren and Ameren Missouri.

Offsetting Derivative Assets and Liabilities

The following table provides the recognized gross derivative balances and the net amounts of those derivatives subject to an enforceable master netting arrangement or similar agreement as of September 30, 2015, and December 31, 2014:

			Gross Amounts Not Offset in the Balance Sheet
Commodity Contracts Eligible to be Offset	Gross Amounts Recognized in the Balance Sheet		Derivative Instruments		Cash Collateral Received/Posted(a)		Net Amount
2015
Assets:
Ameren Missouri	$	24	$	2	$	—	$	22
Ameren Illinois	—		—		—		—
Ameren	$	24	$	2	$	—	$	22
Liabilities:
Ameren Missouri	$	41	$	2	$	6	$	33
Ameren Illinois	214		—		1		213
Ameren	$	255	$	2	$	7	$	246
2014
Assets:
Ameren Missouri	$	18	$	5	$	—	$	13
Ameren Illinois	1		—		—		1
Ameren	$	19	$	5	$	—	$	14
Liabilities:
Ameren Missouri	$	46	$	5	$	5	$	36
Ameren Illinois	186		—		—		186
Ameren	$	232	$	5	$	5	$	222

(a) Cash collateral received reduces gross asset balances and is included in “Other current liabilities” and “Other deferred credits and liabilities” on the balance sheet. Cash collateral posted reduces gross liability balances and is included in “Other current assets” and “Other assets” on the balance sheet.

Derivative Instruments With Credit Risk-Related Contingent Features

The following table presents, as of September 30, 2015, the aggregate fair value of all derivative instruments with credit risk-related contingent features in a gross liability position, the cash collateral posted, and the aggregate amount of additional collateral that could be required to be posted with counterparties. The additional collateral required is the net liability position allowed under the master netting arrangements or similar agreements, assuming (1) the credit risk-related contingent features underlying these arrangements were triggered on September 30, 2015, and (2) those counterparties with rights to do so requested collateral.

	Aggregate Fair Value of Derivative Liabilities(a)		Cash Collateral Posted		Potential Aggregate Amount of Additional Collateral Required(b)
2015
Ameren Missouri	$	88	$	7	$	75
Ameren Illinois	82		1		75
Ameren	$	170	$	8	$	150

(a) Prior to consideration of master netting arrangements or similar agreements and including NPNS and other accrual contract exposures.

(b) As collateral requirements with certain counterparties are based on master netting arrangements or similar agreements, the aggregate amount of additional collateral required to be posted is determined after consideration of the effects of such arrangements.