Segment Information (Tables)

3 Months Ended

Mar. 31, 2018

Schedule Of Segment Reporting Information By Segment

The following tables present revenues, net income attributable to common shareholders, and capital expenditures by segment at Ameren and Ameren Illinois for the three months ended March 31, 2018 and 2017. Ameren, Ameren Missouri, and Ameren Illinois management review segment capital expenditure information rather than any individual or total asset amount.

Ameren



Three Months	Ameren Missouri		Ameren Illinois Electric Distribution		Ameren Illinois Natural Gas		Ameren Transmission			Other			Intersegment Eliminations			Consolidated
2018
External revenues	$	784	$	399	$	311	$	91		$	—		$	—		$	1,585
Intersegment revenues	8		1		—		13			—			(22		)	—
Net income attributable to Ameren common shareholders	38		33		42		37		^(a)	1			—			151
Capital expenditures	249		122		60		145			7			(4		)	579
2017
External revenues	$	773	$	384	$	264	$	96		$	(2	)	$	—		$	1,515
Intersegment revenues	18		1		—		6			—			(25		)	—
Net income attributable to Ameren common shareholders	5		30		33		34		^(a)	—			—			102
Capital expenditures	196		120		51		134			4			(1		)	504


(a)	Ameren Transmission earnings include an allocation of financing costs from Ameren (parent).

Ameren Illinois



Three Months	Ameren Illinois Electric Distribution		Ameren Illinois Natural Gas		Ameren Illinois Transmission		Intersegment Eliminations			Total Ameren Illinois
2018
External revenues	$	400	$	311	$	49	$	—		$	760
Intersegment revenues	—		—		13		(13		)	—
Net income available to common shareholder	33		42		20		—			95
Capital expenditures	122		60		118		—			300
2017
External revenues	$	385	$	264	$	54	$	—		$	703
Intersegment revenues	—		—		6		(6		)	—
Net income available to common shareholder	30		33		16		—			79
Capital expenditures	120		51		56		—			227

Disaggregation of Revenue

The following tables present disaggregated revenues by segment at Ameren and Ameren Illinois for the three months ended March 31, 2018 and 2017. Economic factors affect the nature, timing, amount, and uncertainty of revenues and cash flows in a similar manner across customer classes. Revenues from alternative revenue programs have a similar distribution among customer classes as revenues from contracts with customers. Other revenues not associated with contracts with customers are presented in the Other customer classification, along with electric transmission and off-system revenues.

Ameren



Three Months	Ameren Missouri			Ameren Illinois Electric Distribution		Ameren Illinois Natural Gas			Ameren Transmission		Other			Intersegment Eliminations			Consolidated
2018
Residential	$	332		$	219	$	—		$	—	$	—		$	—		$	551
Commercial	252			124		—			—		—			—			376
Industrial	61			35		—			—		—			—			96
Other	96			22		—			104		—			(22		)	200
Total electric revenues	$	741		$	400	$	—		$	104	$	—		$	(22	)	$	1,223
Residential	$	41		$	—	$	243		$	—	$	—		$	—		$	284
Commercial	16			—		67			—		—			—			83
Industrial	2			—		6			—		—			—			8
Other	(8		)	—		(5		)	—		—			—			(13		)
Total gas revenues	$	51		$	—	$	311		$	—	$	—		$	—		$	362
Total revenues^(a)	$	792		$	400	$	311		$	104	$	—		$	(22	)	$	1,585
2017
Residential	$	290		$	219	$	—		$	—	$	—		$	—		$	509
Commercial	232			133		—			—		—			—			365
Industrial	58			28		—			—		—			—			86
Other	167			5		—			102		(2		)	(25		)	247
Total electric revenues	$	747		$	385	$	—		$	102	$	(2	)	$	(25	)	$	1,207
Residential	$	30		$	—	$	203		$	—	$	—		$	—		$	233
Commercial	12			—		55			—		—			—			67
Industrial	1			—		3			—		—			—			4
Other	1			—		3			—		—			—			4
Total gas revenues	$	44		$	—	$	264		$	—	$	—		$	—		$	308
Total revenues^(b)	$	791		$	385	$	264		$	102	$	(2	)	$	(25	)	$	1,515

(a)

Includes revenues from alternative revenue programs of $(4) million, $31 million, $(3) million, $(4) million, and $20 million at Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, Ameren Transmission, and Ameren, respectively. Also includes other revenues not from contracts with customers of $14 million, $10 million, $1 million, $- million, and $25 million at Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, Ameren Transmission, and Ameren, respectively.

(b)

Includes revenues from alternative revenue programs of $(7) million, $33 million, $11 million, $5 million, and $42 million at Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, Ameren Transmission, and Ameren, respectively. Also includes other revenues not from contracts with customers of $4 million, $2 million, $1 million, $- million, and $7 million at Ameren Missouri, Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, Ameren Transmission, and Ameren, respectively.

Ameren Illinois



Three Months	Ameren Illinois Electric Distribution		Ameren Illinois Natural Gas			Ameren Illinois Transmission		Intersegment Eliminations			Total Ameren Illinois
2018
Residential	$	219	$	243		$	—	$	—		$	462
Commercial	124		67			—		—			191
Industrial	35		6			—		—			41
Other	22		(5		)	62		(13		)	66
Total revenues^(a)	$	400	$	311		$	62	$	(13	)	$	760
2017
Residential	$	219	$	203		$	—	$	—		$	422
Commercial	133		55			—		—			188
Industrial	28		3			—		—			31
Other	5		3			60		(6		)	62
Total revenues^(b)	$	385	$	264		$	60	$	(6	)	$	703

(a)

Includes revenues from alternative revenue programs of $31 million, $(3) million, $(4) million, and $24 million at Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Illinois Transmission, and Ameren Illinois, respectively. Also includes other revenues not from contracts with customers of $10 million, $1 million, $- million, and $11 million at Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, Ameren Illinois Transmission, and Ameren Illinois, respectively.

(b)

Includes revenues from alternative revenue programs of $33 million, $11 million, $3 million, and $47 million at Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, and Ameren Illinois Transmission, and Ameren Illinois, respectively. Also includes other revenues not from contracts with customers of $2 million, $1 million, $- million, and $3 million at Ameren Illinois Electric Distribution, Ameren Illinois Natural Gas, Ameren Illinois Transmission, and Ameren Illinois, respectively.