Financial Derivatives (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Cash and securities held to collateralize net derivative assets	$ 1,400,000,000
Cash and securities pledged to collateralize net derivative liabilities	2,500,000,000
Aggregate fair value of all derivative instruments with credit-risk-related contingent features	2,400,000,000	$ 1,600,000,000
Collateral posted on derivative instruments with credit-risk-related contingent features	1,800,000,000	1,400,000,000
Maximum amount of collateral PNC would have been required to post if the credit-risk-related contingent features underlying these agreements had been triggered	600,000,000	200,000,000
Cash Flow Hedging | Interest Rate Contract
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	187,000,000
Cash flow hedge gain (loss) to be reclassified within twelve months, net of tax	$ 144,000,000
Maximum length of time over which forecasted loan cash flows are hedged	10 years
Net Investment Hedging | Foreign Exchange Contract
Derivative [Line Items]
Gain (loss) from components excluded from assessment of net investment hedge effectiveness net	$ 0	$ 0	$ 0