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 March 31, 2021, and December 31, 2020:


	March 31, 2021						December 31, 2020
	Ameren		Ameren Missouri		Ameren Illinois		Ameren		Ameren Missouri		Ameren Illinois
Cash and cash equivalents	$	6	$	1	$	—	$	139	$	136	$	—
Restricted cash	134		—		125		17		—		6
Restricted cash included in “Other current assets”	—		3		—		—		5		—
Restricted cash included in “Other assets”	24		—		24		141		—		141
Restricted cash included in “Nuclear decommissioning trust fund”	8		8		—		4		4		—
Total cash, cash equivalents, and restricted cash	$	172	$	12	$	149	$	301	$	145	$	147

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. As of December 31, 2020, 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. As of March 31, 2021, the amounts collected under a cost recovery rider restricted for use in Ameren Illinois’ procurement of renewable energy credits was reclassified to current as the amount is expected to be refunded to customers within a year.

“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 March 31, 2021, and December 31, 2020, “Other current liabilities” on Ameren’s and Ameren Illinois’ balance sheets included payables for purchased receivables of $31 million and $28 million, respectively.

The following table provides a reconciliation of the beginning and ending amount of the allowance for doubtful accounts for the three months ended March 31, 2021 and 2020:


	Three Months
		2021		2020
Ameren:
Beginning of period		$	50	$	17
Bad debt expense		4		3

Net write-offs		(7)		(1)

End of period		$	47	$	19
Ameren Missouri:
Beginning of period		$	16	$	7
Bad debt expense		1		2

Net write-offs		(2)		(1)
End of period		$	15	$	8
Ameren Illinois:(a)
Beginning of Period		$	34	$	10
Bad debt expense		3		1

Net write-offs		(5)		—

End of Period		$	32	$	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.

Net write-offs increased for the three months ended March 31, 2021, compared with the year-ago period, due to the resumption of disconnection activities 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 three months ended March 31, 2021 and 2020:


	March 31, 2021						March 31, 2020
	Ameren		Ameren Missouri				Ameren Illinois	Ameren		Ameren Missouri		Ameren Illinois
Investing


Accrued capital expenditures, including wind generation expenditures	$	271	$	141	$	139		$	235	$	97	$	127
Accrued nuclear fuel expenditures	—		—		—			7		7		—
Net realized and unrealized gain (loss) – nuclear decommissioning trust fund	22		22		—			(111)		(111)		—
Financing

Issuance of common stock for stock-based compensation	33		—		—			38		—		—


	Ameren Missouri			Ameren Illinois			Ameren
Balance at December 31, 2020	$	751		$	5	(a)	$	756	(b)
Liabilities incurred (c)	10			—			10
Liabilities settled	(3)			—			(3)
Accretion	8		(d)	—			8		(d)
Change in estimates	(7)		(e)	—			(7)		(e)
Balance at March 31, 2021	$	759		$	5	(a)	$	764	(b)

On January 1, 2021, Ameren granted 293,058 performance share units with a grant date fair value of $25 million and 125,562 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 (251,177 performance share units) or based on the achievement of renewable generation and energy storage installation targets (41,881 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.

For the three months ended March 31, 2021 and 2020, excess tax benefits associated with the settlement of stock-based compensation awards reduced income tax expense by $5 million and $8 million, respectively.

As of both March 31, 2021, and December 31, 2020, the present value of benefits to be paid for deferred compensation obligations was $90 million, which was primarily reflected in “Other deferred credits and liabilities” on Ameren's consolidated balance sheet.

As of March 31, 2021 and 2020, 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 months ended March 31, 2021 and 2020:

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 months ended March 31, 2021 and 2020:


	Three Months
		2021	2020


Weighted-average Common Shares Outstanding – Basic		254.4	246.4
Assumed settlement of performance share units and restricted stock units		1.5	1.1
Dilutive effect of forward sale agreement		—	0.6
Weighted-average Common Shares Outstanding – Diluted(a)		255.9	248.1