Investment Securities (Gains (Losses) on Sales of Securities Available for Sale) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Investment Securities Disclosure [Abstract]
Gross Gains	$ 159	$ 184
Gross Losses	(134)	(2)
Net Gains	25	182
Tax Expense	$ 5	$ 38

Income tax expense related to the gains (losses) of the sale of Available for sale securities.

No definition available.

Name:	pnc_IncomeTaxExpenseAfs
Namespace Prefix:	pnc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Investment Securities Disclosure

+ References

No definition available.

+ Details

Name:	pnc_InvestmentSecuritiesDisclosureAbstract
Namespace Prefix:	pnc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleRealizedGain
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleRealizedGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleRealizedLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration