Income Taxes (Tables)

3 Months Ended

Mar. 31, 2018

Estimated Provisions for Revenue Refund Related to Reduction in Corporate Federal Income Tax Rate

	AEP			AEP Texas			AEPTCo			APCo			I&M			OPCo			PSO			SWEPCo
	(in millions)
Decrease in Total Revenues	$	(119.5	)	$	(7.6	)	$	(19.0	)	$	(35.4	)	$	(17.8	)	$	(21.3	)	$	(3.8	)	$	(11.0	)
Increase in Current Liabilities	33.9			—			16.2			7.8			3.0			6.2			—			—
Increase in Deferred Credits and Other Noncurrent Liabilities	85.6			7.6			2.8			27.6			14.8			15.1			3.8			11.0

Estimated Provisions for Revenue Refund Offsetting Amortization of Excess ADIT

	AEP			AEP Texas			AEPTCo			APCo			I&M			OPCo			PSO			SWEPCo
	(in millions)
Decrease in Total Revenues	$	(17.2	)	$	(2.1	)	$	(0.1	)	$	(4.6	)	$	(1.7	)	$	(1.4	)	$	(2.2	)	$	(3.5	)
Increase in Deferred Credits and Other Noncurrent Liabilities	17.2			2.1			0.1			4.6			1.7			1.4			2.2			3.5

Schedule of Effective Income Tax Rate Reconciliation

	Three Months Ended   March 31,
Company	2018		2017
AEP	18.3	%	36.7	%
AEP Texas	16.3	%	34.7	%
AEPTCo	20.8	%	33.3	%
APCo	18.2	%	36.5	%
I&M	16.2	%	29.9	%
OPCo	20.5	%	34.9	%
PSO	16.3	%	37.7	%
SWEPCo	18.4	%	37.3	%