Fair Value Fair Value (Additional Information Related to Other Financial Instruments Table) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Equity securities without a readily determinable fair value	$ 105	$ 106

Amount of investment in equity security without readily determinable fair value.

No definition available.

Name:	pnc_EquitySecuritieswithoutReadilyDeterminableFairValueAmount
Namespace Prefix:	pnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant