Total Equity and Other Comprehensive Income (Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net unrealized gains (losses) on securities without an allowance for credit losses
Increase in net unrealized gains (losses) on securities	$ 1,669
Less: Net gains (losses) realized as a yield adjustment reclassified to investment securities interest income	1
Less: Net gains (losses) realized on sales of securities reclassified to noninterest income	181
Net increase (decrease), pre-tax	1,487
Effect of income taxes	(341)
Net increase (decrease), after-tax	1,146
Net unrealized gains (losses) on securities with an allowance for credit losses
Increase in net unrealized gains (losses) on securities	(7)
Net increase (decrease), pre-tax	(7)
Effect of income taxes	(2)
Net increase (decrease), after-tax	(5)
Net Unrealized Gains Losses on Non Otti Securities [Abstract]
Increase in net unrealized gains (losses) on non-OTTI securities		$ 640
Less: Net gains (losses) realized as a yield adjustment reclassified to investment securities in interest income		3
Less: Net gains (losses) realized on sales of non-OTTI securities reclassified to noninterest income		(2)
Net increase (decrease), pre-tax		639
Effect of income taxes		(147)
Net increase (decrease), after-tax		492
Net Unrealized Gains Losses On Otti Securities [Abstract]
Increase in net unrealized gains (losses) on OTTI securities		9
Net increase (decrease), pre-tax		9
Effect of income taxes		(2)
Net increase (decrease), after-tax		7
Net unrealized gains (losses) on cash flow hedge derivatives [Abstract]
Increase in net unrealized gains (losses) on cash flow hedge derivatives	830	108
Less: Net gains (losses) realized as a yield adjustment reclassified to loan interest income	42	(8)
Less: Net gains (losses) realized as a yield adjustment reclassified to investment securities interest income	2	1
Less: Net gains (losses) realized on sales of securities reclassified to noninterest income	1	15
Net increase (decrease), pre-tax	785	100
Effect of income taxes	(180)	(23)
Net increase (decrease), after-tax	605	77
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax [Abstract]
Net pension and other postretirement benefit plan activity	10	143
Amortization of actuarial loss (gain) reclassified to other noninterest expense	1	1
Amortization of prior service cost (credit) reclassified to other noninterest expense	1	1
Net increase (decrease), pre-tax	12	145
Effect of income taxes	(3)	(33)
Net increase (decrease), after-tax	9	112
Other Comprehensive Income Other Adjustments [Abstract]
PNC’s portion of BlackRock’s OCI	(34)	29
Net investment hedge derivatives	75	(18)
Foreign currency translation adjustments and other	(67)	23
Net increase (decrease), pre-tax	(26)	34
Effect of income taxes	(10)	(2)
Net increase (decrease), after-tax	(36)	32
Other comprehensive income (loss), before tax and net of reclassifications into Net income	2,251	927
Total other comprehensive income (loss), tax effect	(532)	(207)
Other comprehensive income (loss), after tax and net of reclassifications into Net income	$ 1,719	$ 720