Segment Information (Tables)

9 Months Ended

Sep. 30, 2015

Segment Reporting [Abstract]

Schedule Of Segment Reporting Information By Segment

The following table presents information about the reported revenues and net income attributable to Ameren common stockholders from continuing operations for the three and nine months ended September 30, 2015 and 2014, and total assets of continuing operations as of September 30, 2015, and December 31, 2014:

Three Months	Ameren Missouri		Ameren Illinois		Other			Intersegment Eliminations			Ameren
2015
External revenues	$	1,160	$	654	$	19		$	—		$	1,833
Intersegment revenues	11		1		1			(13		)	—
Net income attributable to Ameren common stockholders from continuing operations	239		98		6			—			343
2014
External revenues	$	1,089	$	572	$	9		$	—		$	1,670
Intersegment revenues	8		—		2			(10		)	—
Net income (loss) attributable to Ameren common stockholders from continuing operations	222		75		(3		)	—			294
Nine Months
2015
External revenues	$	2,825	$	1,910	$	55		$	—		$	4,790
Intersegment revenues	30		3		2			(35		)	—
Net income attributable to Ameren common stockholders from continuing operations	341		182		26			—			549
2014
External revenues	$	2,793	$	1,864	$	26		$	—		$	4,683
Intersegment revenues	21		1		3			(25		)	—
Net income (loss) attributable to Ameren common stockholders from continuing operations	395		156		(10		)	—			541
As of September 30, 2015:
Total assets	$	13,941	$	8,656	$	1,358		$	(513	)	$	23,442	(a)
As of December 31, 2014:
Total assets	$	13,541	$	8,381	$	942		$	(203	)	$	22,661	(a)

(a)    Excludes total assets from discontinued operations of $17 million and $15 million as of September 30, 2015 and December 31, 2014, respectively.