Financial Derivatives (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative [Line Items]
Document Period End Date			Sep. 30, 2018
Increase (Decrease) in Derivative Assets			$ (1,800,000,000)
Increase (Decrease) in Derivative Liabilities			(600,000,000)
Cash And Securities Held To Collateralize Net Derivative Assets	$ 200,000,000		200,000,000
Cash And Securities Pledged To Collateralize Net Derivative Liabilities	1,400,000,000		1,400,000,000
Derivative, Net Liability Position, Aggregate Fair Value	2,200,000,000		2,200,000,000
Collateral already posted, aggregate fair value	800,000,000		800,000,000
Maximum amount of collateral PNC would have been required to post if the credit-risk-related contingent features underlying these agreements had been triggered	1,400,000,000		1,400,000,000
Cash Flow Hedging [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net	0	$ 0	0	$ 0
Gain (Loss) from Components Excluded from Assessment of Cash Flow Hedge Effectiveness, Net	0	0	0	0
Cash Flow Hedge Gain (Loss) To Be Reclassified Within Twelve Months			39,000,000
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months, Net of Tax			$ 31,000,000
Maximum length of time over which forecasted loan cash flows are hedged			10 years
Net Investment Hedging [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Amount Of Ineffectiveness On Net Investment Hedges		0		0
Gain Loss From Components Excluded From Assessment Of Net Investment Hedge Effectiveness Net	0	0	$ 0	0
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income, Effective Portion, Net	17,000,000	(26,000,000)	47,000,000	(76,000,000)
Fair Value Hedging [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Gain (Loss) from Components Excluded from Assessment of Fair Value Hedge Effectiveness, Net	$ 0	$ 0	$ 0	$ 0