Segment Information (Tables)

12 Months Ended

Dec. 31, 2018

Schedule Of Segment Reporting Information, By Segment

The following tables present information about the reported revenue and specified items reflected in net income attributable to common shareholders and capital expenditures by segment at Ameren and Ameren Illinois for the years ended December 31, 2018, 2017, and 2016. Ameren, Ameren Missouri, and Ameren Illinois management review segment capital expenditure information rather than any individual or total asset amount.

Ameren



	Ameren Missouri		Ameren Illinois Electric Distribution		Ameren Illinois Natural Gas		Ameren Transmission			Other			Intersegment Eliminations			Ameren
2018
External revenues	$	3,555	$	1,544	$	814	$	378		$	—		$	—		$	6,291
Intersegment revenues	34		3		1		55		^(a)	—			(93		)	—
Depreciation and amortization	550		259		65		77			4			—			955
Interest income	28		6		—		—			4			(5		)	33
Interest charges	200		73		38		75		^(b)	19			(4		)	401
Income taxes	124		41		25		56			(9		)	—			237
Net income (loss) attributable to Ameren common shareholders	478		136		70		164			(33		)	—			815
Capital expenditures	914		503		311		562			5			(9		)	2,286
2017
External revenues	$	3,488	$	1,564	$	742	$	382		$	(2	)	$	—		$	6,174
Intersegment revenues	49		4		1		44		^(a)	—			(98		)	—
Depreciation and amortization	533		239		59		60			5			—			896
Interest income	27		7		—		—			11			(11		)	34
Interest charges	207		73		36		67		^(b)	19			(11		)	391
Income taxes	254		83		36		90			113			—			576
Net income (loss) attributable to Ameren common shareholders	323		131		60		140			(131		)	—			523
Capital expenditures	773		476		245		644			1			(7		)	2,132
2016
External revenues	$	3,470	$	1,544	$	753	$	309		$	—		$	—		$	6,076
Intersegment revenues	54		4		1		46		^(a)	—			(105		)	—
Depreciation and amortization	514		226		55		43			7			—			845
Interest income	28		11		—		1			11			(11		)	40
Interest charges	211		72		34		58		^(b)	18			(11		)	382
Income taxes	216		78		39		74			(25		)	—			382
Net income (loss) attributable to Ameren common shareholders	357		126		59		117			(6		)	—			653
Capital expenditures	738		470		181		689			4			(6		)	2,076


(a)	Ameren Transmission earns revenue from transmission service provided to Ameren Illinois Electric Distribution. See discussion of transactions above.


(b)	Ameren Transmission interest charges include an allocation of financing costs from Ameren (parent).

Ameren Illinois



	Ameren Illinois Electric Distribution		Ameren Illinois Natural Gas		Ameren Illinois Transmission			Intersegment Eliminations			Ameren Illinois
2018
External revenues	$	1,547	$	815	$	214		$	—		$	2,576
Intersegment revenues	—		—		53		^(a)	(53		)	—
Depreciation and amortization	259		65		50			—			374
Interest income	6		—		—			—			6
Interest charges	73		38		38			—			149
Income taxes	41		25		32			—			98
Net income available to common shareholder	136		70		98			—			304
Capital expenditures	503		311		444			—			1,258
2017
External revenues	$	1,568	$	743	$	216		$	—		$	2,527
Intersegment revenues	—		—		42		^(a)	(42		)	—
Depreciation and amortization	239		59		43			—			341
Interest income	7		—		—			—			7
Interest charges	73		36		35			—			144
Income taxes	83		36		47			—			166
Net income available to common shareholder	131		60		77			—			268
Capital expenditures	476		245		355			—			1,076
2016
External revenues	$	1,548	$	754	$	187		$	—		$	2,489
Intersegment revenues	—		—		45		^(a)	(45		)	—
Depreciation and amortization	226		55		38			—			319
Interest income	11		—		1			—			12
Interest charges	72		34		34			—			140
Income taxes	78		39		41			—			158
Net income available to common shareholder	126		59		67			—			252
Capital expenditures	470		181		273			—			924


(a)	Ameren Illinois Transmission earns revenue from transmission service provided to Ameren Illinois Electric Distribution. See discussion of transactions above.

Disaggregation of Revenue

The following tables present disaggregated revenues by segment at Ameren and Ameren Illinois for the years ended December 31, 2018, 2017, and 2016. 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



	Ameren Missouri			Ameren Illinois Electric Distribution		Ameren Illinois Natural Gas		Ameren Transmission		Other			Intersegment Eliminations			Ameren
2018
Residential	$	1,560		$	867	$	—	$	—	$	—		$	—		$	2,427
Commercial	1,271			511		—		—		—			—			1,782
Industrial	312			130		—		—		—			—			442
Other	308		^(a)	39		—		433		—			(92		)	688		^(a)
Total electric revenues	$	3,451		$	1,547	$	—	$	433	$	—		$	(92	)	$	5,339
Residential	$	90		$	—	$	581	$	—	$	—		$	—		$	671
Commercial	37			—		159		—		—			—			196
Industrial	4			—		17		—		—			—			21
Other	7			—		58		—		—			(1		)	64
Total gas revenues	$	138		$	—	$	815	$	—	$	—		$	(1	)	$	952
Total revenues^(b)	$	3,589		$	1,547	$	815	$	433	$	—		$	(93	)	$	6,291
2017
Residential	$	1,417		$	870	$	—	$	—	$	—		$	—		$	2,287
Commercial	1,208			527		—		—		—			—			1,735
Industrial	305			113		—		—		—			—			418
Other	481			58		—		426		(2		)	(96		)	867
Total electric revenues	$	3,411		$	1,568	$	—	$	426	$	(2	)	$	(96	)	$	5,307
Residential	$	77		$	—	$	531	$	—	$	—		$	—		$	608
Commercial	31			—		146		—		—			—			177
Industrial	4			—		12		—		—			—			16
Other	14			—		54		—		—			(2		)	66
Total gas revenues	$	126		$	—	$	743	$	—	$	—		$	(2	)	$	867
Total revenues^(b)	$	3,537		$	1,568	$	743	$	426	$	(2	)	$	(98	)	$	6,174
2016
Residential	$	1,422		$	895	$	—	$	—	$	—		$	—		$	2,317
Commercial	1,224			517		—		—		—			—			1,741
Industrial	315			96		—		—		—			—			411
Other	435			40		—		355		1			(104		)	727
Total electric revenues	$	3,396		$	1,548	$	—	$	355	$	1		$	(104	)	$	5,196
Residential	$	77		$	—	$	530	$	—	$	—		$	—		$	607
Commercial	30			—		153		—		—			—			183
Industrial	4			—		10		—		—			—			14
Other	17			—		61		—		—			(2		)	76
Total gas revenues	$	128		$	—	$	754	$	—	$	—		$	(2	)	$	880
Total revenues^(b)	$	3,524		$	1,548	$	754	$	355	$	1		$	(106	)	$	6,076


(a)	Includes $60 million for the year ended December 31, 2018, for the reduction to revenue for the excess amounts collected in rates related to the TCJA from January 1, 2018, through July 31, 2018. See Note 2 – Rate and Regulatory Matters for additional information.


(b)	The following table presents increases/(decreases) in revenues from alternative revenue programs and other revenues not from contracts with customers for the years ended December 31, 2018, 2017, and 2016:



	Ameren Missouri			Ameren Illinois Electric Distribution			Ameren Illinois Natural Gas			Ameren Transmission			Ameren
2018
Revenues from alternative revenue programs	$	(8	)	$	(3	)	$	(23	)	$	(25	)	$	(59	)
Other revenues not from contracts with customers	24			16			2			—			42
2017
Revenues from alternative revenue programs	$	(28	)	$	(5	)	$	5		$	13		$	(15	)
Other revenues not from contracts with customers	15			6			2			—			23
2016
Revenues from alternative revenue programs	$	8		$	(70	)	$	11		$	(1	)	$	(52	)
Other revenues not from contracts with customers	16			6			2			—			24

Ameren Illinois



	Ameren Illinois Electric Distribution		Ameren Illinois Natural Gas		Ameren Illinois Transmission		Intersegment Eliminations			Ameren Illinois
2018
Residential	$	867	$	581	$	—	$	—		$	1,448
Commercial	511		159		—		—			670
Industrial	130		17		—		—			147
Other	39		58		267		(53		)	311
Total revenues^(a)	$	1,547	$	815	$	267	$	(53	)	$	2,576
2017
Residential	$	870	$	531	$	—	$	—		$	1,401
Commercial	527		146		—		—			673
Industrial	113		12		—		—			125
Other	58		54		258		(42		)	328
Total revenues^(a)	$	1,568	$	743	$	258	$	(42	)	$	2,527
2016
Residential	$	895	$	530	$	—	$	—		$	1,425
Commercial	517		153		—		—			670
Industrial	96		10		—		—			106
Other	40		61		232		(45		)	288
Total revenues^(a)	$	1,548	$	754	$	232	$	(45	)	$	2,489


(a)	The following table presents increases/(decreases) in revenues from alternative revenue programs and other revenues not from contracts with customers for the Ameren Illinois segments for the years ended December 31, 2018, 2017, and 2016:



	Ameren Illinois Electric Distribution			Ameren Illinois Natural Gas			Ameren Illinois Transmission			Ameren Illinois
2018
Revenues from alternative revenue programs	$	(3	)	$	(23	)	$	(25	)	$	(51	)
Other revenues not from contracts with customers	16			2			—			18
2017
Revenues from alternative revenue programs	$	(5	)	$	5		$	9		$	9
Other revenues not from contracts with customers	6			2			—			8
2016
Revenues from alternative revenue programs	$	(70	)	$	11		$	2		$	(57	)
Other revenues not from contracts with customers	6			2			—			8