Cost Reduction Programs (Tables)

12 Months Ended

Dec. 31, 2015

Disposition Plant Severance [Member]

Remaining Accrual

			Expense										Remaining
	Balance as of		Allocation from		Incurred by								Balance as of
Company	December 31, 2014		AEPSC		Registrants		Settled			Adjustments			December 31, 2015
(in millions)
AEP	$	29.2	$	—	$	2.7	$	22.6		$	—		$	9.3
APCo	9.3		—		0.9		7.0		(a)	(0.1		)	3.1
I&M	8.0		—		0.3		5.4			—			2.9
PSO	0.1		—		0.3		0.2			—			0.2
SWEPCo	0.1		—		—		0.1			—			—

(a) Includes amounts received from affiliates for expenses related to jointly-owned plant.

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	29.2
APCo	7.1
I&M	8.2
OPCo	0.1
PSO	0.3
SWEPCo	0.3

Sustainable Cost Reductions [Member]

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	7.7
APCo	0.3
I&M	0.4
OPCo	5.8
PSO	(0.1		)
SWEPCo	1.0

Appalachian Power Co [Member] | Disposition Plant Severance [Member]

Remaining Accrual

			Expense										Remaining
	Balance as of		Allocation from		Incurred by								Balance as of
Company	December 31, 2014		AEPSC		Registrants		Settled			Adjustments			December 31, 2015
(in millions)
AEP	$	29.2	$	—	$	2.7	$	22.6		$	—		$	9.3
APCo	9.3		—		0.9		7.0		(a)	(0.1		)	3.1
I&M	8.0		—		0.3		5.4			—			2.9
PSO	0.1		—		0.3		0.2			—			0.2
SWEPCo	0.1		—		—		0.1			—			—

(a) Includes amounts received from affiliates for expenses related to jointly-owned plant.

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	29.2
APCo	7.1
I&M	8.2
OPCo	0.1
PSO	0.3
SWEPCo	0.3

Appalachian Power Co [Member] | Sustainable Cost Reductions [Member]

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	7.7
APCo	0.3
I&M	0.4
OPCo	5.8
PSO	(0.1		)
SWEPCo	1.0

Indiana Michigan Power Co [Member] | Disposition Plant Severance [Member]

Remaining Accrual

			Expense										Remaining
	Balance as of		Allocation from		Incurred by								Balance as of
Company	December 31, 2014		AEPSC		Registrants		Settled			Adjustments			December 31, 2015
(in millions)
AEP	$	29.2	$	—	$	2.7	$	22.6		$	—		$	9.3
APCo	9.3		—		0.9		7.0		(a)	(0.1		)	3.1
I&M	8.0		—		0.3		5.4			—			2.9
PSO	0.1		—		0.3		0.2			—			0.2
SWEPCo	0.1		—		—		0.1			—			—

(a) Includes amounts received from affiliates for expenses related to jointly-owned plant.

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	29.2
APCo	7.1
I&M	8.2
OPCo	0.1
PSO	0.3
SWEPCo	0.3

Indiana Michigan Power Co [Member] | Sustainable Cost Reductions [Member]

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	7.7
APCo	0.3
I&M	0.4
OPCo	5.8
PSO	(0.1		)
SWEPCo	1.0

Ohio Power Co [Member] | Disposition Plant Severance [Member]

Remaining Accrual

			Expense										Remaining
	Balance as of		Allocation from		Incurred by								Balance as of
Company	December 31, 2014		AEPSC		Registrants		Settled			Adjustments			December 31, 2015
(in millions)
AEP	$	29.2	$	—	$	2.7	$	22.6		$	—		$	9.3
APCo	9.3		—		0.9		7.0		(a)	(0.1		)	3.1
I&M	8.0		—		0.3		5.4			—			2.9
PSO	0.1		—		0.3		0.2			—			0.2
SWEPCo	0.1		—		—		0.1			—			—

(a) Includes amounts received from affiliates for expenses related to jointly-owned plant.

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	29.2
APCo	7.1
I&M	8.2
OPCo	0.1
PSO	0.3
SWEPCo	0.3

Ohio Power Co [Member] | Sustainable Cost Reductions [Member]

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	7.7
APCo	0.3
I&M	0.4
OPCo	5.8
PSO	(0.1		)
SWEPCo	1.0

Public Service Co Of Oklahoma [Member] | Disposition Plant Severance [Member]

Remaining Accrual

			Expense										Remaining
	Balance as of		Allocation from		Incurred by								Balance as of
Company	December 31, 2014		AEPSC		Registrants		Settled			Adjustments			December 31, 2015
(in millions)
AEP	$	29.2	$	—	$	2.7	$	22.6		$	—		$	9.3
APCo	9.3		—		0.9		7.0		(a)	(0.1		)	3.1
I&M	8.0		—		0.3		5.4			—			2.9
PSO	0.1		—		0.3		0.2			—			0.2
SWEPCo	0.1		—		—		0.1			—			—

(a) Includes amounts received from affiliates for expenses related to jointly-owned plant.

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	29.2
APCo	7.1
I&M	8.2
OPCo	0.1
PSO	0.3
SWEPCo	0.3

Public Service Co Of Oklahoma [Member] | Sustainable Cost Reductions [Member]

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	7.7
APCo	0.3
I&M	0.4
OPCo	5.8
PSO	(0.1		)
SWEPCo	1.0

Southwestern Electric Power Co [Member] | Disposition Plant Severance [Member]

Remaining Accrual

			Expense										Remaining
	Balance as of		Allocation from		Incurred by								Balance as of
Company	December 31, 2014		AEPSC		Registrants		Settled			Adjustments			December 31, 2015
(in millions)
AEP	$	29.2	$	—	$	2.7	$	22.6		$	—		$	9.3
APCo	9.3		—		0.9		7.0		(a)	(0.1		)	3.1
I&M	8.0		—		0.3		5.4			—			2.9
PSO	0.1		—		0.3		0.2			—			0.2
SWEPCo	0.1		—		—		0.1			—			—

(a) Includes amounts received from affiliates for expenses related to jointly-owned plant.

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	29.2
APCo	7.1
I&M	8.2
OPCo	0.1
PSO	0.3
SWEPCo	0.3

Southwestern Electric Power Co [Member] | Sustainable Cost Reductions [Member]

Total Cost Incurred

Company	Total Cost Incurred
	(in millions)
AEP	$	7.7
APCo	0.3
I&M	0.4
OPCo	5.8
PSO	(0.1		)
SWEPCo	1.0