Income Taxes Income Taxes (Tables)

6 Months Ended

Jun. 30, 2017

Summary of Effective Tax Rate

	Three Months Ended June 30,				Six Months Ended June 30,
Company	2017		2016		2017		2016
AEP	34.6	%	24.3	%	36.5	%	28.8	%
AEPTCo	34.2	%	33.1	%	33.9	%	32.1	%
APCo	36.5	%	35.9	%	36.5	%	36.3	%
I&M	27.6	%	32.9	%	29.6	%	28.1	%
OPCo	34.9	%	34.1	%	34.9	%	34.5	%
PSO	37.6	%	36.2	%	37.6	%	35.5	%
SWEPCo	29.7	%	23.6	%	32.4	%	23.7	%

AEP Transmission Co [Member]

Summary of Effective Tax Rate

	Three Months Ended June 30,				Six Months Ended June 30,
Company	2017		2016		2017		2016
AEP	34.6	%	24.3	%	36.5	%	28.8	%
AEPTCo	34.2	%	33.1	%	33.9	%	32.1	%
APCo	36.5	%	35.9	%	36.5	%	36.3	%
I&M	27.6	%	32.9	%	29.6	%	28.1	%
OPCo	34.9	%	34.1	%	34.9	%	34.5	%
PSO	37.6	%	36.2	%	37.6	%	35.5	%
SWEPCo	29.7	%	23.6	%	32.4	%	23.7	%

Appalachian Power Co [Member]

Summary of Effective Tax Rate

	Three Months Ended June 30,				Six Months Ended June 30,
Company	2017		2016		2017		2016
AEP	34.6	%	24.3	%	36.5	%	28.8	%
AEPTCo	34.2	%	33.1	%	33.9	%	32.1	%
APCo	36.5	%	35.9	%	36.5	%	36.3	%
I&M	27.6	%	32.9	%	29.6	%	28.1	%
OPCo	34.9	%	34.1	%	34.9	%	34.5	%
PSO	37.6	%	36.2	%	37.6	%	35.5	%
SWEPCo	29.7	%	23.6	%	32.4	%	23.7	%

Indiana Michigan Power Co [Member]

Summary of Effective Tax Rate

	Three Months Ended June 30,				Six Months Ended June 30,
Company	2017		2016		2017		2016
AEP	34.6	%	24.3	%	36.5	%	28.8	%
AEPTCo	34.2	%	33.1	%	33.9	%	32.1	%
APCo	36.5	%	35.9	%	36.5	%	36.3	%
I&M	27.6	%	32.9	%	29.6	%	28.1	%
OPCo	34.9	%	34.1	%	34.9	%	34.5	%
PSO	37.6	%	36.2	%	37.6	%	35.5	%
SWEPCo	29.7	%	23.6	%	32.4	%	23.7	%

Ohio Power Co [Member]

Summary of Effective Tax Rate

	Three Months Ended June 30,				Six Months Ended June 30,
Company	2017		2016		2017		2016
AEP	34.6	%	24.3	%	36.5	%	28.8	%
AEPTCo	34.2	%	33.1	%	33.9	%	32.1	%
APCo	36.5	%	35.9	%	36.5	%	36.3	%
I&M	27.6	%	32.9	%	29.6	%	28.1	%
OPCo	34.9	%	34.1	%	34.9	%	34.5	%
PSO	37.6	%	36.2	%	37.6	%	35.5	%
SWEPCo	29.7	%	23.6	%	32.4	%	23.7	%

Public Service Co Of Oklahoma [Member]

Summary of Effective Tax Rate

	Three Months Ended June 30,				Six Months Ended June 30,
Company	2017		2016		2017		2016
AEP	34.6	%	24.3	%	36.5	%	28.8	%
AEPTCo	34.2	%	33.1	%	33.9	%	32.1	%
APCo	36.5	%	35.9	%	36.5	%	36.3	%
I&M	27.6	%	32.9	%	29.6	%	28.1	%
OPCo	34.9	%	34.1	%	34.9	%	34.5	%
PSO	37.6	%	36.2	%	37.6	%	35.5	%
SWEPCo	29.7	%	23.6	%	32.4	%	23.7	%

Southwestern Electric Power Co [Member]

Summary of Effective Tax Rate

	Three Months Ended June 30,				Six Months Ended June 30,
Company	2017		2016		2017		2016
AEP	34.6	%	24.3	%	36.5	%	28.8	%
AEPTCo	34.2	%	33.1	%	33.9	%	32.1	%
APCo	36.5	%	35.9	%	36.5	%	36.3	%
I&M	27.6	%	32.9	%	29.6	%	28.1	%
OPCo	34.9	%	34.1	%	34.9	%	34.5	%
PSO	37.6	%	36.2	%	37.6	%	35.5	%
SWEPCo	29.7	%	23.6	%	32.4	%	23.7	%