Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2016

Changes in Carrying Amount of Goodwill

		Corporate and Other			Generation and Marketing		AEP Consolidated
	(in millions)
Balance as of December 31, 2014		$	75.9		$	15.4	$	91.3
Impairment Losses		—			—		—
Goodwill Written Off Related to Sale of AEPRO		(38.8		)	—		(38.8		)
Balance as of December 31, 2015		37.1			15.4		52.5
Impairment Losses		—			—		—
Balance as of December 31, 2016		$	37.1		$	15.4	$	52.5

Amortization Life, Gross Carrying Amount and Accumulated Amortization by Major Asset Class

		December 31,
		2016				2015
	Amortization Life	Gross Carrying Amount		Accumulated Amortization		Gross Carrying Amount		Accumulated Amortization
	(in years)	(in millions)
Acquired Customer Contracts	5	$	58.3	$	58.3	$	58.3	$	56.5