Employee Benefit Plans (Pension Plan Assets Fair Value Hierarchy) (Details) - PNC Pension Plan - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 6,788	$ 6,073
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,047	1,757
Level 1 | Money market funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	725	572
Level 1 | U.S. government and agency securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	583	446
Level 1 | Common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	739	738
Level 1 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,523	1,360
Level 2 | Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11
Level 2 | U.S. government and agency securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	124	126
Level 2 | Corporate debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	962	730
Level 2 | Common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Level 2 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	278	290
Level 2 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	148	214
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	4
Level 3 | Corporate debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	3
Level 3 | Common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	1
Fair Value, Inputs, Level 1, 2 and 3 | Interest bearing cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11
Fair Value, Inputs, Level 1, 2 and 3 | Money market funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	725	572
Fair Value, Inputs, Level 1, 2 and 3 | U.S. government and agency securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	707	572
Fair Value, Inputs, Level 1, 2 and 3 | Corporate debt
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	966	733
Fair Value, Inputs, Level 1, 2 and 3 | Common stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	740	739
Fair Value, Inputs, Level 1, 2 and 3 | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	278	290
Fair Value, Inputs, Level 1, 2 and 3 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	148	215
Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 3,213	$ 2,952