Cost Reduction Programs (Tables)

12 Months Ended

Dec. 31, 2014

Disposition Plant Severance [Member]

Remaining Accrual

	Disposition Plant Severance Activity
	(in millions)
Incurred	$	29
Settled	—
Adjustments	—
Balance as of December 31, 2014	$	29

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

Restructuring and Related Costs [Table Text Block]

	Cost Incurred
	Years Ended December 31,
Company	2013			2012
	(in thousands)
APCo	$	275		$	8,472
I&M	355			5,678
OPCo	5,831			13,498
PSO	(147		)	3,675
SWEPCo	1,017			5,709

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

Remaining Accrual

	Expense Allocation from		Incurred by Registrant								Remaining Balance as of
Company	AEPSC		Subsidiaries		Settled				Adjustments		December 31, 2014
(in thousands)
APCo	$	292	$	6,820	$	2,192		(a)	$	—	$	9,304
I&M	162		8,023		(162		)		—		8,023
OPCo	80		—		(80		)		—		—
PSO	154		134		(154		)		—		134
SWEPCo	205		84		(205		)		—		84

(a) Settled includes amounts received from affiliates for expenses related to joint plant.

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

Restructuring and Related Costs [Table Text Block]

	Cost Incurred
	Years Ended December 31,
Company	2013			2012
	(in thousands)
APCo	$	275		$	8,472
I&M	355			5,678
OPCo	5,831			13,498
PSO	(147		)	3,675
SWEPCo	1,017			5,709

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

Remaining Accrual

	Expense Allocation from		Incurred by Registrant								Remaining Balance as of
Company	AEPSC		Subsidiaries		Settled				Adjustments		December 31, 2014
(in thousands)
APCo	$	292	$	6,820	$	2,192		(a)	$	—	$	9,304
I&M	162		8,023		(162		)		—		8,023
OPCo	80		—		(80		)		—		—
PSO	154		134		(154		)		—		134
SWEPCo	205		84		(205		)		—		84

(a) Settled includes amounts received from affiliates for expenses related to joint plant.

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

Restructuring and Related Costs [Table Text Block]

	Cost Incurred
	Years Ended December 31,
Company	2013			2012
	(in thousands)
APCo	$	275		$	8,472
I&M	355			5,678
OPCo	5,831			13,498
PSO	(147		)	3,675
SWEPCo	1,017			5,709

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

Remaining Accrual

	Expense Allocation from		Incurred by Registrant								Remaining Balance as of
Company	AEPSC		Subsidiaries		Settled				Adjustments		December 31, 2014
(in thousands)
APCo	$	292	$	6,820	$	2,192		(a)	$	—	$	9,304
I&M	162		8,023		(162		)		—		8,023
OPCo	80		—		(80		)		—		—
PSO	154		134		(154		)		—		134
SWEPCo	205		84		(205		)		—		84

(a) Settled includes amounts received from affiliates for expenses related to joint plant.

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

Restructuring and Related Costs [Table Text Block]

	Cost Incurred
	Years Ended December 31,
Company	2013			2012
	(in thousands)
APCo	$	275		$	8,472
I&M	355			5,678
OPCo	5,831			13,498
PSO	(147		)	3,675
SWEPCo	1,017			5,709

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

Remaining Accrual

	Expense Allocation from		Incurred by Registrant								Remaining Balance as of
Company	AEPSC		Subsidiaries		Settled				Adjustments		December 31, 2014
(in thousands)
APCo	$	292	$	6,820	$	2,192		(a)	$	—	$	9,304
I&M	162		8,023		(162		)		—		8,023
OPCo	80		—		(80		)		—		—
PSO	154		134		(154		)		—		134
SWEPCo	205		84		(205		)		—		84

(a) Settled includes amounts received from affiliates for expenses related to joint plant.

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

Restructuring and Related Costs [Table Text Block]

	Cost Incurred
	Years Ended December 31,
Company	2013			2012
	(in thousands)
APCo	$	275		$	8,472
I&M	355			5,678
OPCo	5,831			13,498
PSO	(147		)	3,675
SWEPCo	1,017			5,709

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

Remaining Accrual

	Expense Allocation from		Incurred by Registrant								Remaining Balance as of
Company	AEPSC		Subsidiaries		Settled				Adjustments		December 31, 2014
(in thousands)
APCo	$	292	$	6,820	$	2,192		(a)	$	—	$	9,304
I&M	162		8,023		(162		)		—		8,023
OPCo	80		—		(80		)		—		—
PSO	154		134		(154		)		—		134
SWEPCo	205		84		(205		)		—		84

(a) Settled includes amounts received from affiliates for expenses related to joint plant.