Significant Accounting Matters (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Basic and Diluted EPS Calculations
Earnings Attributable to AEP Common Shareholders	$ 430,000	$ 390,000	$ 1,059,000	$ 950,000
Total Basic Earnings Per Share Attributable to AEP Common Shareholders	$ 0.88	$ 0.80	$ 2.16	$ 1.95
Weighted Average Dilutive Effect of:
Total Diluted Earnings Per Share Attributable to AEP Common Shareholders	$ 0.88	$ 0.80	$ 2.16	$ 1.95
Organization and Summary of Significant Accounting Policies (Textuals) [Abstract]
Antidilutive Shares Outstanding			0	0
Southwestern Electric Power Co [Member]
Basic and Diluted EPS Calculations
Earnings Attributable to AEP Common Shareholders	$ 58,470	$ 31,697	$ 104,174	$ 53,557
Restricted Stock Units [Member]
Weighted Average Dilutive Effect of:
Weighted Average Dilutive Effect of Shares	300,000	200,000	300,000	300,000
Dilutive Securities, Effect on Basic Earnings Per Share	$ 0	$ 0	$ 0.0	$ 0.0