Segment Information

3 Months Ended

Mar. 31, 2016

Segment Reporting [Abstract]

SEGMENT INFORMATION

SEGMENT INFORMATION

Ameren has two reportable segments: Ameren Missouri and Ameren Illinois. Ameren Missouri and Ameren Illinois each have one reportable segment. The Ameren Missouri segment for both Ameren and Ameren Missouri includes all of the operations of Ameren Missouri’s business as described in Note 1 - Summary of Significant Accounting Policies. The Ameren Illinois segment for both Ameren and Ameren Illinois includes all of the operations of Ameren Illinois’ business as described in Note 1 - Summary of Significant Accounting Policies. The category called Other primarily includes Ameren parent company activities, Ameren Services, and ATXI.

The following table presents information about the reported revenues and net income attributable to Ameren common shareholders from continuing operations for the three months ended March 31,2016 and 2015, and total assets of continuing operations as of March 31, 2016, and December 31, 2015:

Three Months	Ameren Missouri		Ameren Illinois		Other		Intersegment Eliminations			Ameren
2016
External revenues	$	726	$	676	$	32	$	—		$	1,434
Intersegment revenues	15		1		—		(16		)	—
Net income attributable to Ameren common shareholders from continuing operations	14		59		32		—			105
2015
External revenues	$	793	$	744	$	19	$	—		$	1,556
Intersegment revenues	7		1		1		(9		)	—
Net income attributable to Ameren common shareholders from continuing operations	41		53		14		—			108
As of March 31, 2016:
Total assets	$	13,443	$	8,944	$	1,214	$	(230	)	$	23,371	(a)
As of December 31, 2015:
Total assets	$	13,851	$	8,903	$	1,139	$	(267	)	$	23,626	(a)

(a)    Excludes total assets from discontinued operations of $14 million as of March 31, 2016, and December 31, 2015.