Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2018

Components of Net Periodic Benefit Cost

AEP

	Pension Plans						OPEB
	Three Months Ended September 30,						Three Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	24.4		$	24.1		$	2.9		$	2.8
Interest Cost	46.9			50.7			11.8			14.8
Expected Return on Plan Assets	(72.6		)	(71.1		)	(25.6		)	(25.3		)
Amortization of Prior Service Cost (Credit)	—			0.3			(17.3		)	(17.3		)
Amortization of Net Actuarial Loss	21.3			20.7			2.7			9.2
Net Periodic Benefit Cost (Credit)	$	20.0		$	24.7		$	(25.5	)	$	(15.8	)

	Pension Plans						OPEB
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	73.2		$	72.3		$	8.7		$	8.4
Interest Cost	140.8			152.3			35.5			44.5
Expected Return on Plan Assets	(217.7		)	(213.5		)	(76.7		)	(76.0		)
Amortization of Prior Service Cost (Credit)	—			0.8			(51.8		)	(51.8		)
Amortization of Net Actuarial Loss	63.9			62.1			7.9			27.5
Net Periodic Benefit Cost (Credit)	$	60.2		$	74.0		$	(76.4	)	$	(47.4	)

AEP Texas

	Pension Plans						OPEB
	Three Months Ended September 30,						Three Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	2.3		$	2.1		$	0.3		$	0.3
Interest Cost	4.0			4.3			0.9			1.2
Expected Return on Plan Assets	(6.4		)	(6.2		)	(2.1		)	(2.2		)
Amortization of Prior Service Credit	—			—			(1.5		)	(1.5		)
Amortization of Net Actuarial Loss	1.8			1.7			0.2			0.8
Net Periodic Benefit Cost (Credit)	$	1.7		$	1.9		$	(2.2	)	$	(1.4	)

	Pension Plans						OPEB
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	6.9		$	6.4		$	0.7		$	0.7
Interest Cost	12.0			12.9			2.8			3.7
Expected Return on Plan Assets	(19.2		)	(18.8		)	(6.4		)	(6.6		)
Amortization of Prior Service Credit	—			—			(4.4		)	(4.4		)
Amortization of Net Actuarial Loss	5.4			5.2			0.6			2.4
Net Periodic Benefit Cost (Credit)	$	5.1		$	5.7		$	(6.7	)	$	(4.2	)

APCo

	Pension Plans						OPEB
	Three Months Ended September 30,						Three Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	2.4		$	2.3		$	0.3		$	0.3
Interest Cost	5.8			6.5			2.1			2.6
Expected Return on Plan Assets	(9.1		)	(8.9		)	(4.0		)	(4.1		)
Amortization of Prior Service Credit	—			—			(2.5		)	(2.5		)
Amortization of Net Actuarial Loss	2.6			2.6			0.4			1.6
Net Periodic Benefit Cost (Credit)	$	1.7		$	2.5		$	(3.7	)	$	(2.1	)

	Pension Plans						OPEB
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	7.0		$	7.0		$	0.8		$	0.8
Interest Cost	17.6			19.3			6.2			7.9
Expected Return on Plan Assets	(27.4		)	(26.8		)	(12.0		)	(12.3		)
Amortization of Prior Service Cost (Credit)	—			0.1			(7.5		)	(7.5		)
Amortization of Net Actuarial Loss	7.9			7.8			1.4			4.7
Net Periodic Benefit Cost (Credit)	$	5.1		$	7.4		$	(11.1	)	$	(6.4	)

I&M

	Pension Plans						OPEB
	Three Months Ended September 30,						Three Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	3.4		$	3.5		$	0.4		$	0.4
Interest Cost	5.6			6.1			1.4			1.7
Expected Return on Plan Assets	(9.0		)	(8.6		)	(3.1		)	(3.1		)
Amortization of Prior Service Credit	—			—			(2.4		)	(2.3		)
Amortization of Net Actuarial Loss	2.5			2.4			0.3			1.1
Net Periodic Benefit Cost (Credit)	$	2.5		$	3.4		$	(3.4	)	$	(2.2	)

	Pension Plans						OPEB
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	10.2		$	10.5		$	1.2		$	1.2
Interest Cost	16.6			18.2			4.1			5.2
Expected Return on Plan Assets	(26.8		)	(25.9		)	(9.3		)	(9.2		)
Amortization of Prior Service Cost (Credit)	—			0.1			(7.1		)	(7.0		)
Amortization of Net Actuarial Loss	7.4			7.3			0.9			3.3
Net Periodic Benefit Cost (Credit)	$	7.4		$	10.2		$	(10.2	)	$	(6.5	)

OPCo

	Pension Plans						OPEB
	Three Months Ended September 30,						Three Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	2.0		$	1.8		$	0.2		$	0.3
Interest Cost	4.4			4.8			1.3			1.6
Expected Return on Plan Assets	(7.2		)	(6.9		)	(2.9		)	(3.0		)
Amortization of Prior Service Credit	—			—			(1.7		)	(1.7		)
Amortization of Net Actuarial Loss	2.0			2.0			0.3			1.1
Net Periodic Benefit Cost (Credit)	$	1.2		$	1.7		$	(2.8	)	$	(1.7	)

	Pension Plans						OPEB
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	5.8		$	5.6		$	0.7		$	0.7
Interest Cost	13.3			14.5			3.9			5.0
Expected Return on Plan Assets	(21.6		)	(20.9		)	(8.8		)	(9.0		)
Amortization of Prior Service Cost (Credit)	—			0.1			(5.2		)	(5.2		)
Amortization of Net Actuarial Loss	6.0			5.9			0.8			3.3
Net Periodic Benefit Cost (Credit)	$	3.5		$	5.2		$	(8.6	)	$	(5.2	)

PSO

	Pension Plans						OPEB
	Three Months Ended September 30,						Three Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	1.7		$	1.7		$	0.1		$	0.2
Interest Cost	2.5			2.6			0.6			0.8
Expected Return on Plan Assets	(4.0		)	(3.9		)	(1.3		)	(1.4		)
Amortization of Prior Service Credit	—			—			(1.1		)	(1.1		)
Amortization of Net Actuarial Loss	1.1			1.1			0.1			0.5
Net Periodic Benefit Cost (Credit)	$	1.3		$	1.5		$	(1.6	)	$	(1.0	)

	Pension Plans						OPEB
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	5.3		$	4.9		$	0.5		$	0.5
Interest Cost	7.4			8.0			1.8			2.4
Expected Return on Plan Assets	(12.1		)	(11.8		)	(4.1		)	(4.2		)
Amortization of Prior Service Credit	—			—			(3.2		)	(3.2		)
Amortization of Net Actuarial Loss	3.3			3.3			0.4			1.5
Net Periodic Benefit Cost (Credit)	$	3.9		$	4.4		$	(4.6	)	$	(3.0	)

SWEPCo

	Pension Plans						OPEB
	Three Months Ended September 30,						Three Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	2.4		$	2.1		$	0.2		$	0.2
Interest Cost	2.8			3.1			0.7			0.9
Expected Return on Plan Assets	(4.4		)	(4.2		)	(1.6		)	(1.5		)
Amortization of Prior Service Credit	—			—			(1.3		)	(1.3		)
Amortization of Net Actuarial Loss	1.3			1.3			0.2			0.5
Net Periodic Benefit Cost (Credit)	$	2.1		$	2.3		$	(1.8	)	$	(1.2	)

	Pension Plans						OPEB
	Nine Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
	(in millions)
Service Cost	$	7.0		$	6.5		$	0.7		$	0.6
Interest Cost	8.5			9.2			2.1			2.7
Expected Return on Plan Assets	(13.1		)	(12.6		)	(4.8		)	(4.7		)
Amortization of Prior Service Credit	—			—			(3.9		)	(3.9		)
Amortization of Net Actuarial Loss	3.8			3.7			0.5			1.7
Net Periodic Benefit Cost (Credit)	$	6.2		$	6.8		$	(5.4	)	$	(3.6	)