Summary Of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2016

Accounting Policies [Abstract]

Summary Of Nonvested Shares Related To Long-Term Incentive Plan

A summary of nonvested performance share units at September 30, 2016, and changes during the nine months ended September 30, 2016, under the 2006 Incentive Plan and the 2014 Incentive Plan are presented below:

	Performance Share Units
	Share Units		Weighted-average Fair Value per Share Unit
Nonvested at January 1, 2016	1,024,870		$	46.08
Granted(a)	587,197		44.13
Forfeitures	(15,949	)	45.07
Vested(b)	(23,114	)	44.41
Nonvested at September 30, 2016	1,573,004		$	45.39

(a) Performance share units granted to certain executive and nonexecutive officers and other eligible employees under the 2014 Incentive Plan.

(b) Performance share units vested due to the attainment of retirement eligibility by certain employees. Actual shares issued for retirement-eligible employees will vary depending on actual performance over the three-year measurement period.

Schedule of Excise Taxes

The following table presents excise taxes recorded in “Operating Revenues – Electric,” “Operating Revenues – Gas” and “Operating Expenses – Taxes other than income taxes” for the three and nine months ended September 30, 2016 and 2015:

	Three Months				Nine Months
	2016		2015		2016		2015
Ameren Missouri	$	52	$	52	$	122	$	127
Ameren Illinois	9		9		40		42
Ameren	$	61	$	61	$	162	$	169