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

3 Months Ended

Mar. 31, 2016

Schedule of Commercial paper [Abstract]

Schedule of Short-term Debt

The following table presents commercial paper outstanding at Ameren (parent), Ameren Missouri, and Ameren Illinois as of March 31, 2016, and December 31, 2015:

	March 31, 2016		December 31, 2015
Ameren (parent)	$	416	$	301
Ameren Missouri	165		—
Ameren Illinois	—		—
Ameren Consolidated	$	581	$	301

The following table summarizes the borrowing activity and relevant interest rates under Ameren’s (parent), Ameren Missouri’s, and Ameren Illinois’ commercial paper programs for the three months ended March 31, 2016 and 2015:

	Ameren (parent)			Ameren Missouri			Ameren Illinois			Ameren Consolidated
2016
Average daily commercial paper outstanding	$	349		$	68		$	—		$	417
Weighted-average interest rate	0.82		%	0.80		%	—		%	0.81		%
Peak commercial paper during period(a)	$	482		$	208		$	—		$	581
Peak interest rate	0.95		%	0.85		%	—		%	0.95		%
2015
Average daily commercial paper outstanding	$	691		$	151		$	10		$	852
Weighted-average interest rate	0.55		%	0.49		%	0.44		%	0.53		%
Peak commercial paper during period(a)	$	815		$	243		$	39		$	955
Peak interest rate	0.70		%	0.60		%	0.60		%	0.70		%

(a) The timing of peak commercial paper issuances varies by company, and therefore the peak amounts presented by company might not equal the Ameren Consolidated peak commercial paper issuances for the period.