Consolidated Statement of Changes in Equity - USD ($) $ in Millions		Total		Cumulative Effect, Period of Adoption, Adjustment		Cumulative Effect, Period of Adoption, Adjusted Balance	[1]	Common stock		Common stock Cumulative Effect, Period of Adoption, Adjusted Balance		Capital Surplus - Preferred Stock		Capital Surplus - Preferred Stock Cumulative Effect, Period of Adoption, Adjusted Balance	[1]	Capital Surplus - Common Stock and Other		Capital Surplus - Common Stock and Other Cumulative Effect, Period of Adoption, Adjusted Balance	[1]	Retained Earnings		Retained Earnings Cumulative Effect, Period of Adoption, Adjustment		Retained Earnings Cumulative Effect, Period of Adoption, Adjusted Balance	[1]	Accumulated Other Comprehensive Income (Loss)		Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjustment	[2]	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjusted Balance	[1]	Treasury Stock		Treasury Stock Cumulative Effect, Period of Adoption, Adjusted Balance	[1]	Noncontrolling Interests		Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjusted Balance	[1]
Beginning Balance (in shares) at Dec. 31, 2017	[1]							473,000,000		473,000,000
Common Stock [Abstract]
Treasury stock activity, shares								(16,000,000)
Ending Balance, (in shares) at Dec. 31, 2018	[1]							457,000,000		457,000,000
Total Equity, Beginning Balance at Dec. 31, 2017		$ 47,585.0	[1]	$ (16.0)	[2]	$ 47,569.0		$ 2,710.0	[1]	$ 2,710.0	[1]	$ 3,985.0	[1]	$ 3,985.0		$ 12,389.0	[1]	$ 12,389.0		$ 35,481.0	[1]	$ (22.0)	[2]	$ 35,459.0		$ (148.0)	[1]	$ 6.0		$ (142.0)		$ (6,904.0)	[1]	$ (6,904.0)		$ 72.0	[1]	$ 72.0
Common Stock [Abstract]
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201602Member
Net income		$ 5,346.0																		5,301.0																45.0
Other comprehensive income (loss), net of tax		(583.0)																								(583.0)
Dividends, Cash [Abstract]
Common		(1,601.0)																		(1,601.0)
Preferred		(236.0)																		(236.0)
Preferred stock discount accretion												4.0								(4.0)
Common stock activity	[3]	20.0						1.0								19.0
Treasury stock activity		(2,651.0)														(101.0)																(2,550.0)
Other		(94.0)										(3.0)				(16.0)																				(75.0)
Total Equity, Ending Balance at Dec. 31, 2018		47,770.0	[1]	62.0	[4]	47,832.0		$ 2,711.0	[1]	$ 2,711.0	[1]	3,986.0	[1]	3,986.0		12,291.0	[1]	12,291.0		38,919.0	[1]	62.0	[4]	38,981.0		(725.0)	[1]			(725.0)		(9,454.0)	[1]	(9,454.0)		42.0	[1]	42.0
Dividends, Cash [Abstract]
Common stock activity, shares								500,000
Par value less than $.5 million at each date		$ 0.5
Treasury stock activity, shares								(24,000,000)
Ending Balance, (in shares) at Dec. 31, 2019	[1]							433,000,000		433,000,000
Common Stock [Abstract]
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201613Member
Net income		$ 5,418.0																		5,369.0																49.0
Other comprehensive income (loss), net of tax		1,524.0																								1,524.0
Dividends, Cash [Abstract]
Common		(1,895.0)																		(1,895.0)
Preferred		(236.0)																		(236.0)
Preferred stock discount accretion												4.0								(4.0)
Common stock activity	[3]	21.0						$ 1.0								20.0
Treasury stock activity		(3,324.0)														3.0																(3,327.0)
Other		3.0										3.0				62.0																				(62.0)
Total Equity, Ending Balance at Dec. 31, 2019		49,343.0	[1]	$ (671.0)	[5]	$ 48,672.0		$ 2,712.0	[1]	$ 2,712.0	[1]	3,993.0	[1]	$ 3,993.0		12,376.0	[1]	$ 12,376.0		42,215.0	[1]	$ (671.0)		$ 41,544.0		799.0	[1]			$ 799.0		(12,781.0)	[1]	$ (12,781.0)		29.0	[1]	$ 29.0
Dividends, Cash [Abstract]
Common stock activity, shares								500,000
Par value less than $.5 million at each date		$ 0.5
Common stock held in treasury at cost (shares)		109,000,000
Treasury stock activity, shares								(9,000,000)
Ending Balance, (in shares) at Dec. 31, 2020								424,000,000
Common Stock [Abstract]
Net income		$ 7,558.0																		7,517.0																41.0
Other comprehensive income (loss), net of tax		1,971.0																								1,971.0
Dividends, Cash [Abstract]
Common		(1,980.0)																		(1,980.0)
Preferred		(229.0)																		(229.0)
Preferred stock discount accretion												4.0								(4.0)
Common stock activity	[3]	24.0						$ 1.0								23.0
Treasury stock activity		(1,370.0)														54.0																(1,424.0)
Other		(125.0)														(86.0)																				(39.0)
Preferred stock redemption - Series Q	[6]	(480.0)										(480.0)
Total Equity, Ending Balance at Dec. 31, 2020		54,041.0						$ 2,713.0				$ 3,517.0				$ 12,367.0				$ 46,848.0						$ 2,770.0						$ (14,205.0)				$ 31.0
Dividends, Cash [Abstract]
Common stock activity, shares	[3]							500,000
Par value less than $.5 million at each date		$ 0.5
Common stock held in treasury at cost (shares)		119,000,000

[1] The par value of our preferred stock outstanding was less than $0.5 million at each date and, therefore, is excluded from this presentation.

[2] Represents the cumulative effect of adopting ASU 2014-09, ASU 2016-01, ASU 2017-12 and ASU 2018-02.

[3] Common stock activity totaled less than 0.5 million shares issued.

[4] Represents the impact of the adoption of ASU 2016-02 related primarily to deferred gains on previous sale-leaseback transactions.

[5] Represents the impact of the adoption ASU 2016-13 - Financial Instruments - Credit Losses. See the Recently Adopted Accounting Standards portion of Note 1 Accounting Policies in this Report for additional detail on this adoption.

[6] On September 1, 2020, PNC redeemed all 4,800 shares of its Series Q Preferred Stock, as well as all 19.2 million Depositary Shares representing fractional interest in such shares