Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2015

Components of Net Periodic Benefit Cost

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended September 30,						Three Months Ended September 30,
	2015			2014			2015			2014
	(in millions)
Service Cost	$	23		$	18		$	3		$	4
Interest Cost	51			55			15			16
Expected Return on Plan Assets	(69		)	(65		)	(28		)	(28		)
Amortization of Prior Service Cost (Credit)	1			1			(18		)	(18		)
Amortization of Net Actuarial Loss	27			31			5			6
Net Periodic Benefit Cost (Credit)	$	33		$	40		$	(23	)	$	(20	)

	Pension Plans						Other Postretirement Benefit Plans
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
	(in millions)
Service Cost	$	70		$	54		$	9		$	11
Interest Cost	154			166			43			50
Expected Return on Plan Assets	(206		)	(196		)	(83		)	(84		)
Amortization of Prior Service Cost (Credit)	2			2			(52		)	(52		)
Amortization of Net Actuarial Loss	80			93			14			17
Net Periodic Benefit Cost (Credit)	$	100		$	119		$	(69	)	$	(58	)

Appalachian Power Co [Member]

Components of Net Periodic Benefit Cost

APCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended September 30,						Three Months Ended September 30,
	2015			2014			2015			2014
	(in thousands)
Service Cost	$	2,175		$	1,759		$	286		$	362
Interest Cost	6,679			7,406			2,584			3,197
Expected Return on Plan Assets	(8,745		)	(8,482		)	(4,529		)	(4,634		)
Amortization of Prior Service Cost (Credit)	45			49			(2,513		)	(2,512		)
Amortization of Net Actuarial Loss	3,474			4,149			900			1,145
Net Periodic Benefit Cost (Credit)	$	3,628		$	4,881		$	(3,272	)	$	(2,442	)

	Pension Plans						Other Postretirement Benefit Plans
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
	(in thousands)
Service Cost	$	6,525		$	5,277		$	857		$	1,086
Interest Cost	20,037			22,218			7,753			9,591
Expected Return on Plan Assets	(26,236		)	(25,445		)	(13,587		)	(13,900		)
Amortization of Prior Service Cost (Credit)	135			148			(7,538		)	(7,537		)
Amortization of Net Actuarial Loss	10,421			12,445			2,699			3,436
Net Periodic Benefit Cost (Credit)	$	10,882		$	14,643		$	(9,816	)	$	(7,324	)

Indiana Michigan Power Co [Member]

Components of Net Periodic Benefit Cost

I&M

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended September 30,						Three Months Ended September 30,
	2015			2014			2015			2014
	(in thousands)
Service Cost	$	3,217		$	2,517		$	406		$	486
Interest Cost	6,114			6,573			1,592			1,909
Expected Return on Plan Assets	(8,115		)	(7,749		)	(3,304		)	(3,363		)
Amortization of Prior Service Cost (Credit)	45			49			(2,355		)	(2,355		)
Amortization of Net Actuarial Loss	3,145			3,647			506			592
Net Periodic Benefit Cost (Credit)	$	4,406		$	5,037		$	(3,155	)	$	(2,731	)

	Pension Plans						Other Postretirement Benefit Plans
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
	(in thousands)
Service Cost	$	9,651		$	7,551		$	1,219		$	1,460
Interest Cost	18,344			19,720			4,776			5,728
Expected Return on Plan Assets	(24,347		)	(23,245		)	(9,912		)	(10,090		)
Amortization of Prior Service Cost (Credit)	136			146			(7,066		)	(7,066		)
Amortization of Net Actuarial Loss	9,434			10,939			1,519			1,776
Net Periodic Benefit Cost (Credit)	$	13,218		$	15,111		$	(9,464	)	$	(8,192	)

Ohio Power Co [Member]

Components of Net Periodic Benefit Cost

OPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended September 30,						Three Months Ended September 30,
	2015			2014			2015			2014
	(in thousands)
Service Cost	$	1,671		$	1,285		$	216		$	256
Interest Cost	5,071			5,527			1,615			1,900
Expected Return on Plan Assets	(6,878		)	(6,607		)	(3,376		)	(3,379		)
Amortization of Prior Service Cost (Credit)	35			40			(1,731		)	(1,731		)
Amortization of Net Actuarial Loss	2,644			3,105			517			595
Net Periodic Benefit Cost (Credit)	$	2,543		$	3,350		$	(2,759	)	$	(2,359	)

	Pension Plans						Other Postretirement Benefit Plans
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
	(in thousands)
Service Cost	$	5,015		$	3,855		$	647		$	769
Interest Cost	15,211			16,579			4,845			5,701
Expected Return on Plan Assets	(20,634		)	(19,820		)	(10,130		)	(10,139		)
Amortization of Prior Service Cost (Credit)	105			118			(5,192		)	(5,192		)
Amortization of Net Actuarial Loss	7,932			9,316			1,552			1,785
Net Periodic Benefit Cost (Credit)	$	7,629		$	10,048		$	(8,278	)	$	(7,076	)

Public Service Co Of Oklahoma [Member]

Components of Net Periodic Benefit Cost

PSO

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended September 30,						Three Months Ended September 30,
	2015			2014			2015			2014
	(in thousands)
Service Cost	$	1,598		$	1,301		$	170		$	209
Interest Cost	2,731			3,015			759			893
Expected Return on Plan Assets	(3,786		)	(3,651		)	(1,578		)	(1,575		)
Amortization of Prior Service Cost (Credit)	63			74			(1,072		)	(1,072		)
Amortization of Net Actuarial Loss	1,418			1,689			242			278
Net Periodic Benefit Cost (Credit)	$	2,024		$	2,428		$	(1,479	)	$	(1,267	)

	Pension Plans						Other Postretirement Benefit Plans
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
	(in thousands)
Service Cost	$	4,796		$	3,905		$	509		$	629
Interest Cost	8,194			9,043			2,277			2,680
Expected Return on Plan Assets	(11,358		)	(10,953		)	(4,732		)	(4,725		)
Amortization of Prior Service Cost (Credit)	189			222			(3,217		)	(3,217		)
Amortization of Net Actuarial Loss	4,252			5,065			725			832
Net Periodic Benefit Cost (Credit)	$	6,073		$	7,282		$	(4,438	)	$	(3,801	)

Southwestern Electric Power Co [Member]

Components of Net Periodic Benefit Cost

SWEPCo

	Pension Plans						Other Postretirement Benefit Plans
	Three Months Ended September 30,						Three Months Ended September 30,
	2015			2014			2015			2014
	(in thousands)
Service Cost	$	2,081		$	1,655		$	211		$	253
Interest Cost	2,932			3,163			837			998
Expected Return on Plan Assets	(4,008		)	(3,857		)	(1,735		)	(1,754		)
Amortization of Prior Service Cost (Credit)	78			87			(1,289		)	(1,289		)
Amortization of Net Actuarial Loss	1,506			1,762			266			309
Net Periodic Benefit Cost (Credit)	$	2,589		$	2,810		$	(1,710	)	$	(1,483	)

	Pension Plans						Other Postretirement Benefit Plans
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2015			2014			2015			2014
	(in thousands)
Service Cost	$	6,244		$	4,964		$	632		$	759
Interest Cost	8,796			9,488			2,512			2,994
Expected Return on Plan Assets	(12,024		)	(11,571		)	(5,206		)	(5,262		)
Amortization of Prior Service Cost (Credit)	232			262			(3,867		)	(3,867		)
Amortization of Net Actuarial Loss	4,520			5,285			798			926
Net Periodic Benefit Cost (Credit)	$	7,768		$	8,428		$	(5,131	)	$	(4,450	)