Related Party Transactions (Tables)

12 Months Ended

Dec. 31, 2015

Appalachian Power Co [Member]

Affiliated Revenues

Related Party Revenues	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2015
Direct Sales to East Affiliates	$	132.1	$	—	$	—	$	—	$	—
Auction Sales to OPCo (a)	10.6		17.1		—		—		—
Direct Sales to AEPEP	—		—		29.7		—		(0.2		)
Transmission Agreement and Transmission Coordination Agreement Sales	0.7		8.4		35.5		0.2		15.2
Other Revenues	4.4		1.9		18.9		4.4		1.6
Total Affiliated Revenues	$	147.8	$	27.4	$	84.1	$	4.6	$	16.6

Related Party Revenues	APCo			I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2014
Sales under Interconnection Agreement (b)	$	0.2		$	0.5	$	1.1	$	—	$	—
Direct Sales to East Affiliates	141.7			—		—		3.8		10.1
Direct Sales to West Affiliates	0.6			0.4		—		—		0.3
Direct Sales to AEPEP	—			—		44.1		—		—
Transmission Agreement and Transmission Coordination Agreement Sales	(1.6		)	1.7		104.1		—		14.1
Other Revenues	3.6			1.6		15.9		3.3		1.8
Total Affiliated Revenues	$	144.5		$	4.2	$	165.2	$	7.1	$	26.3

Related Party Revenues	APCo		I&M			OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2013
Sales under Interconnection Agreement	$	193.7	$	218.2		$	924.3	$	—	$	—
Direct Sales to East Affiliates	129.0		—			152.7		—		—
Direct Sales to West Affiliates	0.6		0.4			0.8		10.8		35.4
Direct Sales to AEPEP	—		—			—		—		(0.1		)
Transmission Agreement and Transmission Coordination Agreement Sales	0.4		(0.7		)	53.4		—		14.7
Other Revenues	23.8		1.5			35.7		3.4		1.8
Total Affiliated Revenues	$	347.5	$	219.4		$	1,166.9	$	14.2	$	51.8

(a)    Refer to the Ohio Auctions section below for further information regarding these amounts.

(b)    Includes December 2013 true-up activity subsequent to agreement termination.

Affiliated Purchases

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2015
Direct Purchases from AGR	$	—	$	—	$	238.5	$	—	$	—
Auction Purchases from AEPEP (a)	—		—		225.2		—		—
Auction Purchases from AEPSC (a)	—		—		32.7		—		—
Direct Purchases from AEGCo	—		232.1		—		—		—
Total Affiliated Purchases	$	—	$	232.1	$	496.4	$	—	$	—

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2014
Purchases under Interconnection Agreement (b)	$	4.7	$	1.6	$	0.1	$	—	$	—
Direct Purchases from East Affiliates	—		—		—		1.0		—
Direct Purchases from West Affiliates	—		—		—		10.0		3.8
Direct Purchases from AGR	—		—		1,148.2		—		—
Direct Purchases from AEPEP	—		—		44.4		—		—
Direct Purchases from AEGCo	—		268.4		—		—		—
Total Affiliated Purchases	$	4.7	$	270.0	$	1,192.7	$	11.0	$	3.8

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2013
Purchases under Interconnection Agreement	$	830.9	$	181.7	$	199.3	$	—	$	—
Direct Purchases from East Affiliates	—		—		—		1.5		0.4
Direct Purchases from West Affiliates	—		—		—		35.4		10.8
Direct Purchases from AEGCo	—		251.5		148.4		—		—
Natural Gas Purchases from AEPES	—		—		2.0		—		—
Total Affiliated Purchases	$	830.9	$	433.2	$	349.7	$	36.9	$	11.2

(a)    Refer to the Ohio Auctions section below for further information regarding this amount.

(b)    Includes December 2013 true-up activity subsequent to agreement termination.

Transmission Agreement

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	92.7	$	84.7	$	40.6
I&M	38.0		39.7		19.9
OPCo	81.0		17.0		8.9

Barging, Urea Transloading and Other Services

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
AEGCo	$	16.1	$	22.7	$	19.7
AGR	4.9		5.2		—
APCo	37.7		36.1		30.9
KPCo	4.6		5.0		0.1
OPCo	—		—		40.6
AEP River Operations LLC – (Nonutility Subsidiary of AEP)	15.5		25.3		22.6

Central Machine Shop

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
AEGCo	$	0.1	$	0.1	$	—
AGR	2.7		2.8		—
I&M	2.5		1.7		2.5
KPCo	1.3		1.2		0.7
OPCo	—		—		4.7
PSO	0.2		0.3		0.6
SWEPCo	0.8		0.1		0.2

Affiliate Railcar Agreement

	December 31, 2015
	Billing Company
Billed Company	APCo		I&M		PSO		SWEPCo
	(in millions)
APCo	$	—	$	—	$	0.3	$	0.3
I&M	—		—		0.4		1.2
PSO	—		0.6		—		0.6
SWEPCo	—		1.8		0.6		—

	December 31, 2014
	Billing Company
Billed Company	APCo		I&M		PSO		SWEPCo
	(in millions)
I&M	$	0.3	$	—	$	0.1	$	1.1
PSO	0.1		1.3		—		0.7
SWEPCo	0.1		2.2		0.2		—

Ownership and Investment in OVEC

	December 31, 2015
Company	Ownership		Investment
			(in millions)
Parent	39.17	%	$	4.0
OPCo	4.30	%	0.4
Total	43.47	%	$	4.4

Purchased Power from OVEC

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	87.2	$	96.9	$	104.4
I&M	43.7		48.5		52.2
OPCo	110.8		123.1		132.6

Related Party Sales of Property

Sales

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	9.4	$	3.0	$	3.2
I&M	3.0		1.3		5.0
OPCo	2.4		0.5		59.8
PSO	7.1		0.5		5.7
SWEPCo	0.8		1.2		1.6

Related Party Purchases of Property

Purchases

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	8.6	$	0.9	$	5.2
I&M	8.1		1.4		1.0
OPCo	2.1		1.9		5.3
PSO	0.6		2.1		1.7
SWEPCo	7.4		4.0		8.4

Indiana Michigan Power Co [Member]

Affiliated Revenues

Related Party Revenues	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2015
Direct Sales to East Affiliates	$	132.1	$	—	$	—	$	—	$	—
Auction Sales to OPCo (a)	10.6		17.1		—		—		—
Direct Sales to AEPEP	—		—		29.7		—		(0.2		)
Transmission Agreement and Transmission Coordination Agreement Sales	0.7		8.4		35.5		0.2		15.2
Other Revenues	4.4		1.9		18.9		4.4		1.6
Total Affiliated Revenues	$	147.8	$	27.4	$	84.1	$	4.6	$	16.6

Related Party Revenues	APCo			I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2014
Sales under Interconnection Agreement (b)	$	0.2		$	0.5	$	1.1	$	—	$	—
Direct Sales to East Affiliates	141.7			—		—		3.8		10.1
Direct Sales to West Affiliates	0.6			0.4		—		—		0.3
Direct Sales to AEPEP	—			—		44.1		—		—
Transmission Agreement and Transmission Coordination Agreement Sales	(1.6		)	1.7		104.1		—		14.1
Other Revenues	3.6			1.6		15.9		3.3		1.8
Total Affiliated Revenues	$	144.5		$	4.2	$	165.2	$	7.1	$	26.3

Related Party Revenues	APCo		I&M			OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2013
Sales under Interconnection Agreement	$	193.7	$	218.2		$	924.3	$	—	$	—
Direct Sales to East Affiliates	129.0		—			152.7		—		—
Direct Sales to West Affiliates	0.6		0.4			0.8		10.8		35.4
Direct Sales to AEPEP	—		—			—		—		(0.1		)
Transmission Agreement and Transmission Coordination Agreement Sales	0.4		(0.7		)	53.4		—		14.7
Other Revenues	23.8		1.5			35.7		3.4		1.8
Total Affiliated Revenues	$	347.5	$	219.4		$	1,166.9	$	14.2	$	51.8

(a)    Refer to the Ohio Auctions section below for further information regarding these amounts.

(b)    Includes December 2013 true-up activity subsequent to agreement termination.

Affiliated Purchases

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2015
Direct Purchases from AGR	$	—	$	—	$	238.5	$	—	$	—
Auction Purchases from AEPEP (a)	—		—		225.2		—		—
Auction Purchases from AEPSC (a)	—		—		32.7		—		—
Direct Purchases from AEGCo	—		232.1		—		—		—
Total Affiliated Purchases	$	—	$	232.1	$	496.4	$	—	$	—

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2014
Purchases under Interconnection Agreement (b)	$	4.7	$	1.6	$	0.1	$	—	$	—
Direct Purchases from East Affiliates	—		—		—		1.0		—
Direct Purchases from West Affiliates	—		—		—		10.0		3.8
Direct Purchases from AGR	—		—		1,148.2		—		—
Direct Purchases from AEPEP	—		—		44.4		—		—
Direct Purchases from AEGCo	—		268.4		—		—		—
Total Affiliated Purchases	$	4.7	$	270.0	$	1,192.7	$	11.0	$	3.8

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2013
Purchases under Interconnection Agreement	$	830.9	$	181.7	$	199.3	$	—	$	—
Direct Purchases from East Affiliates	—		—		—		1.5		0.4
Direct Purchases from West Affiliates	—		—		—		35.4		10.8
Direct Purchases from AEGCo	—		251.5		148.4		—		—
Natural Gas Purchases from AEPES	—		—		2.0		—		—
Total Affiliated Purchases	$	830.9	$	433.2	$	349.7	$	36.9	$	11.2

(a)    Refer to the Ohio Auctions section below for further information regarding this amount.

(b)    Includes December 2013 true-up activity subsequent to agreement termination.

Transmission Agreement

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	92.7	$	84.7	$	40.6
I&M	38.0		39.7		19.9
OPCo	81.0		17.0		8.9

Coal Transloading

AEGCo

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
I&M	$	15.8	$	16.2	$	6.8
OPCo	—		—		0.3

OPCo

	Years Ended December 31,
Company	2013
	(in millions)
I&M	$	15.6	(a)

(a) Includes $7 million in 2013 of amounts purchased by I&M on behalf of AEGCo for Rockport Plant through July 31, 2013.

Railcar Maintenance

AEGCo

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
I&M	$	2.0	$	2.5	$	1.1
PSO	0.2		0.3		0.1
SWEPCo	2.8		3.3		1.2

OPCo

	Years Ended December 31,
Company	2013
	(in millions)
I&M	$	1.3	(a)
PSO	0.1
SWEPCo	1.2

(a) Includes $608 thousand in 2013 of amounts purchased by I&M on behalf of AEGCo for Rockport Plant through July 31, 2013.

Barging, Urea Transloading and Other Services

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
AEGCo	$	16.1	$	22.7	$	19.7
AGR	4.9		5.2		—
APCo	37.7		36.1		30.9
KPCo	4.6		5.0		0.1
OPCo	—		—		40.6
AEP River Operations LLC – (Nonutility Subsidiary of AEP)	15.5		25.3		22.6

Central Machine Shop

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
AEGCo	$	0.1	$	0.1	$	—
AGR	2.7		2.8		—
I&M	2.5		1.7		2.5
KPCo	1.3		1.2		0.7
OPCo	—		—		4.7
PSO	0.2		0.3		0.6
SWEPCo	0.8		0.1		0.2

Affiliate Railcar Agreement

	December 31, 2015
	Billing Company
Billed Company	APCo		I&M		PSO		SWEPCo
	(in millions)
APCo	$	—	$	—	$	0.3	$	0.3
I&M	—		—		0.4		1.2
PSO	—		0.6		—		0.6
SWEPCo	—		1.8		0.6		—

	December 31, 2014
	Billing Company
Billed Company	APCo		I&M		PSO		SWEPCo
	(in millions)
I&M	$	0.3	$	—	$	0.1	$	1.1
PSO	0.1		1.3		—		0.7
SWEPCo	0.1		2.2		0.2		—

Ownership and Investment in OVEC

	December 31, 2015
Company	Ownership		Investment
			(in millions)
Parent	39.17	%	$	4.0
OPCo	4.30	%	0.4
Total	43.47	%	$	4.4

Purchased Power from OVEC

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	87.2	$	96.9	$	104.4
I&M	43.7		48.5		52.2
OPCo	110.8		123.1		132.6

Related Party Sales of Property

Sales

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	9.4	$	3.0	$	3.2
I&M	3.0		1.3		5.0
OPCo	2.4		0.5		59.8
PSO	7.1		0.5		5.7
SWEPCo	0.8		1.2		1.6

Related Party Purchases of Property

Purchases

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	8.6	$	0.9	$	5.2
I&M	8.1		1.4		1.0
OPCo	2.1		1.9		5.3
PSO	0.6		2.1		1.7
SWEPCo	7.4		4.0		8.4

Ohio Power Co [Member]

Affiliated Revenues

Related Party Revenues	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2015
Direct Sales to East Affiliates	$	132.1	$	—	$	—	$	—	$	—
Auction Sales to OPCo (a)	10.6		17.1		—		—		—
Direct Sales to AEPEP	—		—		29.7		—		(0.2		)
Transmission Agreement and Transmission Coordination Agreement Sales	0.7		8.4		35.5		0.2		15.2
Other Revenues	4.4		1.9		18.9		4.4		1.6
Total Affiliated Revenues	$	147.8	$	27.4	$	84.1	$	4.6	$	16.6

Related Party Revenues	APCo			I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2014
Sales under Interconnection Agreement (b)	$	0.2		$	0.5	$	1.1	$	—	$	—
Direct Sales to East Affiliates	141.7			—		—		3.8		10.1
Direct Sales to West Affiliates	0.6			0.4		—		—		0.3
Direct Sales to AEPEP	—			—		44.1		—		—
Transmission Agreement and Transmission Coordination Agreement Sales	(1.6		)	1.7		104.1		—		14.1
Other Revenues	3.6			1.6		15.9		3.3		1.8
Total Affiliated Revenues	$	144.5		$	4.2	$	165.2	$	7.1	$	26.3

Related Party Revenues	APCo		I&M			OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2013
Sales under Interconnection Agreement	$	193.7	$	218.2		$	924.3	$	—	$	—
Direct Sales to East Affiliates	129.0		—			152.7		—		—
Direct Sales to West Affiliates	0.6		0.4			0.8		10.8		35.4
Direct Sales to AEPEP	—		—			—		—		(0.1		)
Transmission Agreement and Transmission Coordination Agreement Sales	0.4		(0.7		)	53.4		—		14.7
Other Revenues	23.8		1.5			35.7		3.4		1.8
Total Affiliated Revenues	$	347.5	$	219.4		$	1,166.9	$	14.2	$	51.8

(a)    Refer to the Ohio Auctions section below for further information regarding these amounts.

(b)    Includes December 2013 true-up activity subsequent to agreement termination.

Affiliated Purchases

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2015
Direct Purchases from AGR	$	—	$	—	$	238.5	$	—	$	—
Auction Purchases from AEPEP (a)	—		—		225.2		—		—
Auction Purchases from AEPSC (a)	—		—		32.7		—		—
Direct Purchases from AEGCo	—		232.1		—		—		—
Total Affiliated Purchases	$	—	$	232.1	$	496.4	$	—	$	—

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2014
Purchases under Interconnection Agreement (b)	$	4.7	$	1.6	$	0.1	$	—	$	—
Direct Purchases from East Affiliates	—		—		—		1.0		—
Direct Purchases from West Affiliates	—		—		—		10.0		3.8
Direct Purchases from AGR	—		—		1,148.2		—		—
Direct Purchases from AEPEP	—		—		44.4		—		—
Direct Purchases from AEGCo	—		268.4		—		—		—
Total Affiliated Purchases	$	4.7	$	270.0	$	1,192.7	$	11.0	$	3.8

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2013
Purchases under Interconnection Agreement	$	830.9	$	181.7	$	199.3	$	—	$	—
Direct Purchases from East Affiliates	—		—		—		1.5		0.4
Direct Purchases from West Affiliates	—		—		—		35.4		10.8
Direct Purchases from AEGCo	—		251.5		148.4		—		—
Natural Gas Purchases from AEPES	—		—		2.0		—		—
Total Affiliated Purchases	$	830.9	$	433.2	$	349.7	$	36.9	$	11.2

(a)    Refer to the Ohio Auctions section below for further information regarding this amount.

(b)    Includes December 2013 true-up activity subsequent to agreement termination.

Transmission Agreement

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	92.7	$	84.7	$	40.6
I&M	38.0		39.7		19.9
OPCo	81.0		17.0		8.9

Coal Transloading

AEGCo

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
I&M	$	15.8	$	16.2	$	6.8
OPCo	—		—		0.3

OPCo

	Years Ended December 31,
Company	2013
	(in millions)
I&M	$	15.6	(a)

(a) Includes $7 million in 2013 of amounts purchased by I&M on behalf of AEGCo for Rockport Plant through July 31, 2013.

Railcar Maintenance

AEGCo

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
I&M	$	2.0	$	2.5	$	1.1
PSO	0.2		0.3		0.1
SWEPCo	2.8		3.3		1.2

OPCo

	Years Ended December 31,
Company	2013
	(in millions)
I&M	$	1.3	(a)
PSO	0.1
SWEPCo	1.2

(a) Includes $608 thousand in 2013 of amounts purchased by I&M on behalf of AEGCo for Rockport Plant through July 31, 2013.

Barging, Urea Transloading and Other Services

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
AEGCo	$	16.1	$	22.7	$	19.7
AGR	4.9		5.2		—
APCo	37.7		36.1		30.9
KPCo	4.6		5.0		0.1
OPCo	—		—		40.6
AEP River Operations LLC – (Nonutility Subsidiary of AEP)	15.5		25.3		22.6

Central Machine Shop

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
AEGCo	$	0.1	$	0.1	$	—
AGR	2.7		2.8		—
I&M	2.5		1.7		2.5
KPCo	1.3		1.2		0.7
OPCo	—		—		4.7
PSO	0.2		0.3		0.6
SWEPCo	0.8		0.1		0.2

Ownership and Investment in OVEC

	December 31, 2015
Company	Ownership		Investment
			(in millions)
Parent	39.17	%	$	4.0
OPCo	4.30	%	0.4
Total	43.47	%	$	4.4

Purchased Power from OVEC

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	87.2	$	96.9	$	104.4
I&M	43.7		48.5		52.2
OPCo	110.8		123.1		132.6

Related Party Sales of Property

Sales

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	9.4	$	3.0	$	3.2
I&M	3.0		1.3		5.0
OPCo	2.4		0.5		59.8
PSO	7.1		0.5		5.7
SWEPCo	0.8		1.2		1.6

Related Party Purchases of Property

Purchases

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	8.6	$	0.9	$	5.2
I&M	8.1		1.4		1.0
OPCo	2.1		1.9		5.3
PSO	0.6		2.1		1.7
SWEPCo	7.4		4.0		8.4

Public Service Co Of Oklahoma [Member]

Affiliated Revenues

Related Party Revenues	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2015
Direct Sales to East Affiliates	$	132.1	$	—	$	—	$	—	$	—
Auction Sales to OPCo (a)	10.6		17.1		—		—		—
Direct Sales to AEPEP	—		—		29.7		—		(0.2		)
Transmission Agreement and Transmission Coordination Agreement Sales	0.7		8.4		35.5		0.2		15.2
Other Revenues	4.4		1.9		18.9		4.4		1.6
Total Affiliated Revenues	$	147.8	$	27.4	$	84.1	$	4.6	$	16.6

Related Party Revenues	APCo			I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2014
Sales under Interconnection Agreement (b)	$	0.2		$	0.5	$	1.1	$	—	$	—
Direct Sales to East Affiliates	141.7			—		—		3.8		10.1
Direct Sales to West Affiliates	0.6			0.4		—		—		0.3
Direct Sales to AEPEP	—			—		44.1		—		—
Transmission Agreement and Transmission Coordination Agreement Sales	(1.6		)	1.7		104.1		—		14.1
Other Revenues	3.6			1.6		15.9		3.3		1.8
Total Affiliated Revenues	$	144.5		$	4.2	$	165.2	$	7.1	$	26.3

Related Party Revenues	APCo		I&M			OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2013
Sales under Interconnection Agreement	$	193.7	$	218.2		$	924.3	$	—	$	—
Direct Sales to East Affiliates	129.0		—			152.7		—		—
Direct Sales to West Affiliates	0.6		0.4			0.8		10.8		35.4
Direct Sales to AEPEP	—		—			—		—		(0.1		)
Transmission Agreement and Transmission Coordination Agreement Sales	0.4		(0.7		)	53.4		—		14.7
Other Revenues	23.8		1.5			35.7		3.4		1.8
Total Affiliated Revenues	$	347.5	$	219.4		$	1,166.9	$	14.2	$	51.8

(a)    Refer to the Ohio Auctions section below for further information regarding these amounts.

(b)    Includes December 2013 true-up activity subsequent to agreement termination.

Affiliated Purchases

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2015
Direct Purchases from AGR	$	—	$	—	$	238.5	$	—	$	—
Auction Purchases from AEPEP (a)	—		—		225.2		—		—
Auction Purchases from AEPSC (a)	—		—		32.7		—		—
Direct Purchases from AEGCo	—		232.1		—		—		—
Total Affiliated Purchases	$	—	$	232.1	$	496.4	$	—	$	—

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2014
Purchases under Interconnection Agreement (b)	$	4.7	$	1.6	$	0.1	$	—	$	—
Direct Purchases from East Affiliates	—		—		—		1.0		—
Direct Purchases from West Affiliates	—		—		—		10.0		3.8
Direct Purchases from AGR	—		—		1,148.2		—		—
Direct Purchases from AEPEP	—		—		44.4		—		—
Direct Purchases from AEGCo	—		268.4		—		—		—
Total Affiliated Purchases	$	4.7	$	270.0	$	1,192.7	$	11.0	$	3.8

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2013
Purchases under Interconnection Agreement	$	830.9	$	181.7	$	199.3	$	—	$	—
Direct Purchases from East Affiliates	—		—		—		1.5		0.4
Direct Purchases from West Affiliates	—		—		—		35.4		10.8
Direct Purchases from AEGCo	—		251.5		148.4		—		—
Natural Gas Purchases from AEPES	—		—		2.0		—		—
Total Affiliated Purchases	$	830.9	$	433.2	$	349.7	$	36.9	$	11.2

(a)    Refer to the Ohio Auctions section below for further information regarding this amount.

(b)    Includes December 2013 true-up activity subsequent to agreement termination.

Transmission Coordination Agreement

	Years Ended December 31,
Company	2015			2014			2013
	(in millions)
PSO	$	15.0		$	14.1		$	14.7
SWEPCo	(15.0		)	(14.1		)	(14.7		)

Railcar Maintenance

AEGCo

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
I&M	$	2.0	$	2.5	$	1.1
PSO	0.2		0.3		0.1
SWEPCo	2.8		3.3		1.2

OPCo

	Years Ended December 31,
Company	2013
	(in millions)
I&M	$	1.3	(a)
PSO	0.1
SWEPCo	1.2

(a) Includes $608 thousand in 2013 of amounts purchased by I&M on behalf of AEGCo for Rockport Plant through July 31, 2013.

Central Machine Shop

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
AEGCo	$	0.1	$	0.1	$	—
AGR	2.7		2.8		—
I&M	2.5		1.7		2.5
KPCo	1.3		1.2		0.7
OPCo	—		—		4.7
PSO	0.2		0.3		0.6
SWEPCo	0.8		0.1		0.2

Affiliate Railcar Agreement

	December 31, 2015
	Billing Company
Billed Company	APCo		I&M		PSO		SWEPCo
	(in millions)
APCo	$	—	$	—	$	0.3	$	0.3
I&M	—		—		0.4		1.2
PSO	—		0.6		—		0.6
SWEPCo	—		1.8		0.6		—

	December 31, 2014
	Billing Company
Billed Company	APCo		I&M		PSO		SWEPCo
	(in millions)
I&M	$	0.3	$	—	$	0.1	$	1.1
PSO	0.1		1.3		—		0.7
SWEPCo	0.1		2.2		0.2		—

Related Party Sales of Property

Sales

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	9.4	$	3.0	$	3.2
I&M	3.0		1.3		5.0
OPCo	2.4		0.5		59.8
PSO	7.1		0.5		5.7
SWEPCo	0.8		1.2		1.6

Related Party Purchases of Property

Purchases

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	8.6	$	0.9	$	5.2
I&M	8.1		1.4		1.0
OPCo	2.1		1.9		5.3
PSO	0.6		2.1		1.7
SWEPCo	7.4		4.0		8.4

Southwestern Electric Power Co [Member]

Affiliated Revenues

Related Party Revenues	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2015
Direct Sales to East Affiliates	$	132.1	$	—	$	—	$	—	$	—
Auction Sales to OPCo (a)	10.6		17.1		—		—		—
Direct Sales to AEPEP	—		—		29.7		—		(0.2		)
Transmission Agreement and Transmission Coordination Agreement Sales	0.7		8.4		35.5		0.2		15.2
Other Revenues	4.4		1.9		18.9		4.4		1.6
Total Affiliated Revenues	$	147.8	$	27.4	$	84.1	$	4.6	$	16.6

Related Party Revenues	APCo			I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2014
Sales under Interconnection Agreement (b)	$	0.2		$	0.5	$	1.1	$	—	$	—
Direct Sales to East Affiliates	141.7			—		—		3.8		10.1
Direct Sales to West Affiliates	0.6			0.4		—		—		0.3
Direct Sales to AEPEP	—			—		44.1		—		—
Transmission Agreement and Transmission Coordination Agreement Sales	(1.6		)	1.7		104.1		—		14.1
Other Revenues	3.6			1.6		15.9		3.3		1.8
Total Affiliated Revenues	$	144.5		$	4.2	$	165.2	$	7.1	$	26.3

Related Party Revenues	APCo		I&M			OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2013
Sales under Interconnection Agreement	$	193.7	$	218.2		$	924.3	$	—	$	—
Direct Sales to East Affiliates	129.0		—			152.7		—		—
Direct Sales to West Affiliates	0.6		0.4			0.8		10.8		35.4
Direct Sales to AEPEP	—		—			—		—		(0.1		)
Transmission Agreement and Transmission Coordination Agreement Sales	0.4		(0.7		)	53.4		—		14.7
Other Revenues	23.8		1.5			35.7		3.4		1.8
Total Affiliated Revenues	$	347.5	$	219.4		$	1,166.9	$	14.2	$	51.8

(a)    Refer to the Ohio Auctions section below for further information regarding these amounts.

(b)    Includes December 2013 true-up activity subsequent to agreement termination.

Affiliated Purchases

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2015
Direct Purchases from AGR	$	—	$	—	$	238.5	$	—	$	—
Auction Purchases from AEPEP (a)	—		—		225.2		—		—
Auction Purchases from AEPSC (a)	—		—		32.7		—		—
Direct Purchases from AEGCo	—		232.1		—		—		—
Total Affiliated Purchases	$	—	$	232.1	$	496.4	$	—	$	—

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2014
Purchases under Interconnection Agreement (b)	$	4.7	$	1.6	$	0.1	$	—	$	—
Direct Purchases from East Affiliates	—		—		—		1.0		—
Direct Purchases from West Affiliates	—		—		—		10.0		3.8
Direct Purchases from AGR	—		—		1,148.2		—		—
Direct Purchases from AEPEP	—		—		44.4		—		—
Direct Purchases from AEGCo	—		268.4		—		—		—
Total Affiliated Purchases	$	4.7	$	270.0	$	1,192.7	$	11.0	$	3.8

Related Party Purchases	APCo		I&M		OPCo		PSO		SWEPCo
	(in millions)
Year Ended December 31, 2013
Purchases under Interconnection Agreement	$	830.9	$	181.7	$	199.3	$	—	$	—
Direct Purchases from East Affiliates	—		—		—		1.5		0.4
Direct Purchases from West Affiliates	—		—		—		35.4		10.8
Direct Purchases from AEGCo	—		251.5		148.4		—		—
Natural Gas Purchases from AEPES	—		—		2.0		—		—
Total Affiliated Purchases	$	830.9	$	433.2	$	349.7	$	36.9	$	11.2

(a)    Refer to the Ohio Auctions section below for further information regarding this amount.

(b)    Includes December 2013 true-up activity subsequent to agreement termination.

Transmission Coordination Agreement

	Years Ended December 31,
Company	2015			2014			2013
	(in millions)
PSO	$	15.0		$	14.1		$	14.7
SWEPCo	(15.0		)	(14.1		)	(14.7		)

Railcar Maintenance

AEGCo

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
I&M	$	2.0	$	2.5	$	1.1
PSO	0.2		0.3		0.1
SWEPCo	2.8		3.3		1.2

OPCo

	Years Ended December 31,
Company	2013
	(in millions)
I&M	$	1.3	(a)
PSO	0.1
SWEPCo	1.2

(a) Includes $608 thousand in 2013 of amounts purchased by I&M on behalf of AEGCo for Rockport Plant through July 31, 2013.

Central Machine Shop

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
AEGCo	$	0.1	$	0.1	$	—
AGR	2.7		2.8		—
I&M	2.5		1.7		2.5
KPCo	1.3		1.2		0.7
OPCo	—		—		4.7
PSO	0.2		0.3		0.6
SWEPCo	0.8		0.1		0.2

Affiliate Railcar Agreement

	December 31, 2015
	Billing Company
Billed Company	APCo		I&M		PSO		SWEPCo
	(in millions)
APCo	$	—	$	—	$	0.3	$	0.3
I&M	—		—		0.4		1.2
PSO	—		0.6		—		0.6
SWEPCo	—		1.8		0.6		—

	December 31, 2014
	Billing Company
Billed Company	APCo		I&M		PSO		SWEPCo
	(in millions)
I&M	$	0.3	$	—	$	0.1	$	1.1
PSO	0.1		1.3		—		0.7
SWEPCo	0.1		2.2		0.2		—

Related Party Sales of Property

Sales

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	9.4	$	3.0	$	3.2
I&M	3.0		1.3		5.0
OPCo	2.4		0.5		59.8
PSO	7.1		0.5		5.7
SWEPCo	0.8		1.2		1.6

Related Party Purchases of Property

Purchases

	Years Ended December 31,
Company	2015		2014		2013
	(in millions)
APCo	$	8.6	$	0.9	$	5.2
I&M	8.1		1.4		1.0
OPCo	2.1		1.9		5.3
PSO	0.6		2.1		1.7
SWEPCo	7.4		4.0		8.4