Short-Term Debt And Liquidity Short-Term Debt and Liquidity (Tables)

3 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Schedule of Short-term Debt

The following table presents commercial paper outstanding, net of issuance discounts, as of March 31, 2018, and December 31, 2017:

	2018		2017
Ameren (parent)	$	454	$	383
Ameren Missouri	282		39
Ameren Illinois	224		62
Ameren Consolidated	$	960	$	484

The following table summarizes the borrowing activity and relevant interest rates under Ameren (parent)’s, Ameren Missouri’s, and Ameren Illinois’ commercial paper programs for the three months ended March 31, 2018 and 2017:

	Ameren (parent)			Ameren Missouri			Ameren Illinois			Ameren Consolidated
2018
Average daily commercial paper outstanding at par value	$	378		$	213		$	137		$	728
Weighted-average interest rate	1.90		%	1.88		%	1.96		%	1.90		%
Peak commercial paper during period at par value(a)	$	454		$	282		$	238		$	960
Peak interest rate	2.35		%	2.40		%	2.55		%	2.55		%
2017
Average daily commercial paper outstanding at par value	$	682		$	4		$	50		$	736
Weighted-average interest rate	1.07		%	0.93		%	0.95		%	1.06		%
Peak commercial paper during period at par value(a)	$	810		$	45		$	74		$	914
Peak interest rate	1.30		%	1.15		%	1.15		%	1.30		%

(a) The timing of peak outstanding commercial paper issuances varies by company. Therefore, the sum of individual company peak amounts may not equal the Ameren Consolidated peak commercial paper issuances for the period.