Utility Rate Regulation Utility Rate Regulation (Other) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
PPL Electric [Member] | Unaffiliated Third Party Entity [Member]
Purchases Of Accounts Receivable [Line Items]
Purchases of accounts receivable	$ 1,300	$ 1,400	$ 1,300
PPL Electric Utilities Corp [Member] | Unaffiliated Third Party Entity [Member]
Purchases Of Accounts Receivable [Line Items]
Purchases of accounts receivable	$ 1,300	$ 1,400	1,300
PPL Electric Utilities Corp [Member] | PPL EnergyPlus [Member]
Purchases Of Accounts Receivable [Line Items]
Purchases of accounts receivable			$ 146