Supplemental Information (Tables)

6 Months Ended

Jun. 30, 2019

Supplemental Information [Abstract]

Schedule of Cash and Cash Equivalents Including Restricted Cash

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets and the statements of cash flows as of June 30, 2019, and December 31, 2018:

	June 30, 2019						December 31, 2018
	Ameren		Ameren Missouri		Ameren Illinois		Ameren		Ameren Missouri		Ameren Illinois
Cash and cash equivalents	$	6	$	—	$	—	$	16	$	—	$	—
Restricted cash included in “Other current assets”	6		—		2		13		4		6
Restricted cash included in “Other assets”	97		—		97		74		—		74
Restricted cash included in “Nuclear decommissioning trust fund”	13		13		—		4		4		—
Total cash, cash equivalents, and restricted cash	$	122	$	13	$	99	$	107	$	8	$	80

Lease Supplemental Information

The following table provides supplemental balance sheet information related to operating leases as of June 30, 2019:

	Ameren			Ameren Missouri
Other assets	$	35		$	32
Other current liabilities	7			6
Other deferred credits and liabilities	28			26
Weighted average remaining operating lease term	6 years			6 years
Weighted average discount rate(a)	3.6		%	3.6		%

(a)

As most of our lease agreements do not provide an implicit rate, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. We use the implicit rate when readily determinable.

Schedule of Maturity of Operating Lease Liabilities

The following table presents Ameren’s and Ameren Missouri’s remaining maturities of operating lease liabilities as of June 30, 2019:

	Ameren		Ameren Missouri
2019	$	4	$	4
2020	7		7
2021	7		6
2022	6		5
2023	5		5
Thereafter	10		9
Total lease payments	39		36
Less imputed interest	4		4
Total(a)	$	35	$	32

(a)

The amount of remaining maturities of operating lease liabilities under previous authoritative accounting guidance as of December 31, 2018, is materially consistent with the amount as of June 30, 2019. Maturities of certain financing arrangements, including the Peno Creek and Audrain energy centers' long-term agreements, are no longer required to be disclosed as lease-related maturities. See Note 5 - Long-Term Debt and Equity Financings under Part II, Item 8, in the Form 10-K for further information on financing arrangements.

Schedule of Cash Flow, Supplemental Disclosures

Supplemental Cash Flow Information

The following table provides noncash investing activity excluded from the statements of cash flows for the six months ended June 30, 2019 and 2018:

	June 30, 2019						June 30, 2018
	Ameren		Ameren Missouri		Ameren Illinois		Ameren		Ameren Missouri		Ameren Illinois
Accrued capital expenditures	$	263	$	101	$	143	$	233	$	80	$	147
Net realized and unrealized gain (loss) – nuclear decommissioning trust fund	90		90		—		1		1		—

Asset Retirement Obligation Disclosure

The following table provides a reconciliation of the beginning and ending carrying amount of AROs for the six months ended June 30, 2019:

	Ameren Missouri				Ameren Illinois(a)			Ameren
Balance at December 31, 2018	$	646		(a)	$	4	(b)	$	650		(a)
Liabilities settled	(7		)		—			(7		)
Accretion	14			(c)	—			14			(c)
Change in estimates	33			(d)	—			33			(d)
Balance at June 30, 2019	$	686		(a)	$	4	(b)	$	690		(a)

(a) Balance included $23 million in “Other current liabilities” on the balance sheet as of both December 31, 2018, and June 30, 2019.

(b) Included in “Other deferred credits and liabilities” on the balance sheet.

(c) Accretion expense attributable to Ameren Missouri was recorded as a decrease to regulatory liabilities.

(d)

Ameren Missouri changed its fair value estimate primarily due to an increase in the cost estimate for closure of certain CCR storage facilities.

Summary Of Nonvested Shares Related To Long-Term Incentive Plan

The following table summarizes Ameren's nonvested performance share unit and restricted stock unit activity for the six months ended June 30, 2019:

	Performance Share Units					Restricted Stock Units
	Share Units		Weighted-average Fair Value per Share Unit			Stock Units		Weighted-average Fair Value per Stock Unit
Nonvested at January 1, 2019(a)	682,811		$	56.58		155,253		$	57.38
Granted	294,871		67.42		(b)	128,415		65.46
Forfeitures	(14,564	)	64.13			(4,465	)	62.62
Vested and undistributed(c)	(122,451	)	62.19			(27,301	)	61.87
Vested and distributed	(176,923	)	44.13			—		—
Nonvested at June 30, 2019(d)	663,744		$	63.52		251,902		$	60.80

(a) Does not include 619,783 performance share units and 26,557 restricted stock units that were vested and undistributed.

(b) Significant inputs to the Monte Carlo simulation model used to calculate the fair value of performance share units granted include Ameren’s closing common share price of $65.23 at December 31, 2018, Ameren’s common stock volatility of 17%, a volatility range for the peer group of 15% to 25%, and a three-year risk-free rate of 2.46%.

(c) Vested and undistributed units are awards that vested due to attainment of retirement eligibility by certain employees, but have not yet been distributed. For vested and undistributed performance share units, the number of shares issued for retirement-eligible employees will vary depending on actual performance over the three year performance period.

(d)

Does not include 390,459 performance share units and 53,858 restricted stock units that were vested and undistributed.

Schedule of excise taxes

The following table presents the excise taxes recorded on a gross basis in “Operating Revenues – Electric,” “Operating Revenues – Natural gas” and “Operating Expenses – Taxes other than income taxes” on the statements of income for the three and six months ended June 30, 2019 and 2018:

	Three Months				Six Months
	2019		2018		2019		2018
Ameren Missouri	$	38	$	46	$	69	$	80
Ameren Illinois	25		28		64		63
Ameren	$	63	$	74	$	133	$	143