Borrowed Funds (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total borrowed funds	$ 59,088	$ 52,706
PNC Capital Trust C
Debt Instrument [Line Items]
Carrrying value - junior subordinated debt	205
Trust preferred securities	200
Parent Company
Debt Instrument [Line Items]
Total borrowed funds	6,848	6,203
Bank
Debt Instrument [Line Items]
Total borrowed funds	47,451	42,327
Senior Notes \| Parent Company
Debt Instrument [Line Items]
Total borrowed funds	5,203	3,960
Basis adjustments - Fair value accounting hedges	38
Senior Notes \| Bank
Debt Instrument [Line Items]
Total borrowed funds	22,859	19,012
Basis adjustments - Fair value accounting hedges	(187)
Subordinated Debt \| Parent Company
Debt Instrument [Line Items]
Total borrowed funds	1,440	2,038
Basis adjustments - Fair value accounting hedges	23
Subordinated Debt \| Bank
Debt Instrument [Line Items]
Total borrowed funds	3,555	$ 5,766
Basis adjustments - Fair value accounting hedges	$ 2
3-month LIBOR \| PNC Capital Trust C
Debt Instrument [Line Items]
Basis Spread on LIBOR Rate - trust preferred securities	0.57%

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- Definition

In order to issue trust preferred securities, a sponsor forms a trust by investing a nominal amount of cash to purchase all of the voting common stock of the trust. The trust issues nonvoting, mandatorily redeemable preferred securities to outside investors in exchange for cash. The proceeds received from the issuance of the preferred securities, together with the cash received for issuing the common stock to the sponsor, is then loaned to the sponsor in exchange for a note which has the same terms as the trust preferred securities. Trust preferred securities possesses characteristics of both equity and debt issues and are generally issued by bank holding companies.

+ References

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- Definition

Sum of the carrying values as of the balance sheet date of all debt, including all short-term borrowings, long-term debt, and capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.13,16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

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+ References

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Junior Subordinated Notes, which have a lower priority than senior instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16)(a))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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