Consolidated Balance Sheets (FirstEnergy Solutions Corp.) (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Common stockholders’ equity-
Common stock, shares authorized	490,000,000	490,000,000
Common stock, shares outstanding	442,344,218	423,560,397
Customer [Member]
Receivables-
Allowance for uncollectible accounts (in dollars)	$ 53	$ 69
Other Receivables [Member]
Receivables-
Allowance for uncollectible accounts (in dollars)	$ 1	$ 5
FES
Common stockholders’ equity-
Common stock, no par value
Common stock, shares authorized	750	750
Common stock, shares outstanding	7	7
FES | Customer [Member]
Receivables-
Allowance for uncollectible accounts (in dollars)	$ 5	$ 8
FES | Other Receivables [Member]
Receivables-
Allowance for uncollectible accounts (in dollars)	$ 0	$ 3