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 September 30, 2020, and December 31, 2019:


	September 30, 2020						December 31, 2019
	Ameren		Ameren Missouri		Ameren Illinois		Ameren		Ameren Missouri		Ameren Illinois
Cash and cash equivalents	$	6	$	—	$	—	$	16	$	9	$	—
Restricted cash included in “Other current assets”	14		4		5		14		4		5
Restricted cash included in “Other assets”	142		—		142		120		—		120
Restricted cash included in “Nuclear decommissioning trust fund”	6		6		—		26		26		—
Total cash, cash equivalents, and restricted cash	$	168	$	10	$	147	$	176	$	39	$	125

Restricted cash included in “Other current assets” primarily represents funds held by an irrevocable Voluntary Employee Beneficiary Association (VEBA) trust, which provides health care benefits for active employees. Restricted cash included in “Other assets” on Ameren’s and Ameren Illinois’ balance sheets primarily represents amounts collected under a cost recovery rider restricted for use in the procurement of renewable energy credits and amounts in a trust fund restricted for the use of funding certain asbestos-related claims.

“Accounts receivable – trade” on Ameren’s and Ameren Illinois’ balance sheets include certain receivables purchased at a discount from alternative retail electric suppliers that elect to participate in the utility consolidated billing program. At September 30, 2020, and December 31, 2019, “Other current liabilities” on Ameren’s and Ameren Illinois’ balance sheets included payables for purchased receivables of $36 million and $32 million, respectively.

The following table provides a reconciliation of the beginning and ending amount of the allowance for doubtful accounts for the three and nine months ended September 30, 2020 and 2019:


	Three Months				Nine Months
	2020		2019		2020		2019
Ameren:
Beginning of period	$	25	$	19	$	17	$	18
Bad debt expense	21		14		31		22

Net write-offs	(2)		(14)		(4)		(21)

End of period	$	44	$	19	$	44	$	19
Ameren Missouri:
Beginning of period	$	9	$	7	$	7	$	7
Bad debt expense	5		3		9		6

Net write-offs	—		(2)		(2)		(5)
End of period	$	14	$	8	$	14	$	8
Ameren Illinois:(a)
Beginning of Period	$	16	$	12	$	10	$	11
Bad debt expense	16		11		22		16

Net write-offs	(2)		(12)		(2)		(16)

End of Period	$	30	$	11	$	30	$	11

(a)Ameren Illinois has rate-adjustment mechanisms that allow it to recover the difference between its actual net bad debt write-offs under GAAP, including those associated with receivables purchased from alternative retail electric suppliers, and the amount of net bad debt write-offs included in its base rates. In 2020, the rate-adjustment mechanism for electric distribution allows for recovery of bad debt expense recognized under GAAP. See Note 2 – Rate and Regulatory Matters for additional information.

Net write-offs decreased for the three and nine months ended September 30, 2020, compared with the year-ago periods, due to the temporary suspension of disconnecting customers for nonpayment. See Note 2 – Rate and Regulatory Matters for additional information.

The following table provides noncash financing and investing activity excluded from the statements of cash flows for the nine months ended September 30, 2020 and 2019:


	September 30, 2020						September 30, 2019
	Ameren		Ameren Missouri				Ameren Illinois	Ameren		Ameren Missouri		Ameren Illinois
Investing

Exchange of bond investments for the extinguishment of senior unsecured notes	$	—	$	—	$	—		$	17	$	—	$	17
Accrued capital expenditures	311		115		191			273		138		128

Net realized and unrealized gain (loss) – nuclear decommissioning trust fund	43		43		—			100		100		—
Financing
Exchange of bond investments for the extinguishment of senior unsecured notes	$	—	$	—	$	—		$	(17)	$	—	$	(17)
Issuance of common stock for stock-based compensation	38		—		—			54		—		—


	Ameren Missouri			Ameren Illinois			Ameren
Balance at December 31, 2019	$	687		$	4	(a)	$	691	(b)

Liabilities settled	(42)			—			(42)
Accretion	21		(c)	1		(c)	22		(c)
Change in estimates	57		(d)	—			57		(d)
Balance at September 30, 2020	$	723		$	5	(a)	$	728	(b)

(c)Accretion expense attributable to Ameren Missouri and Ameren Illinois was recorded as a decrease to regulatory liabilities and an increase to regulatory assets, respectively.

(d)Ameren Missouri changed its fair value estimate primarily due to an update to the decommissioning of the Callaway Energy Center to reflect the cost study and funding analysis filed with the MoPSC in November 2020 and an increase in the cost estimate for closure of certain CCR storage facilities.

On January 1, 2020, Ameren granted 294,320 performance share units with a grant date fair value of $24 million and 132,307 restricted share units with a grant date fair value of $10 million. Awards vest approximately 38 months after the grant date or on a pro-rata basis upon death or eligible retirement. The performance share units vest based on the achievement of certain specified market performance measures (252,370 performance share units) or based on the achievement of renewable generation and energy storage installation targets (41,950 performance share units). The exact number of shares issued pursuant to a performance share unit varies from 0% to 200% of the target award, depending on actual company performance relative to the performance goals.

On September 18, 2020, Ameren granted certain executive officers an additional 37,104 restricted share units with a grant date fair value of $3 million, which will vest after three years on September 17, 2023. The awards do not provide for pro rata vesting in connection with the executive officer's retirement.

For the nine months ended September 30, 2020 and 2019, excess tax benefits associated with the settlement of stock-based compensation awards reduced income tax expense by $8 million and $14 million, respectively.

As of September 30, 2020, and December 31, 2019, the present value of benefits to be paid for deferred compensation obligations was $88 million and $86 million, respectively, which was primarily reflected in “Other deferred credits and liabilities” on Ameren's consolidated balance sheet.

As of September 30, 2020 and 2019, our remaining performance obligations for contracts with a term greater than one year were immaterial. The Ameren Companies elected not to disclose the aggregate amount of the transaction price allocated to the performance obligations that are unsatisfied as of the end of the reporting period for contracts with an initial expected term of one year or less.

Ameren Missouri and Ameren Illinois collect from their customers excise taxes, including municipal and state excise taxes and gross receipts taxes that are levied on the sale or distribution of natural gas and electricity. 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 nine months ended September 30, 2020 and 2019:

The following table reconciles the basic weighted-average number of common shares outstanding to the diluted weighted-average number of common shares outstanding for the three and nine months ended September 30, 2020 and 2019:


	Three Months		Nine Months
	2020	2019	2020	2019


Weighted-average Common Shares Outstanding – Basic	247.1	245.9	246.8	245.5
Assumed settlement of performance share units and restricted stock units	1.5	1.4	1.2	1.4
Dilutive effect of forward sale agreement	0.6	0.2	0.4	0.1
Weighted-average Common Shares Outstanding – Diluted(a)	249.2	247.5	248.4	247.0

(a)There were no potentially dilutive securities excluded from the earnings per diluted share calculations for the three and nine months ended September 30, 2020 and 2019.