Parent Company (Income Statement) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Expenses [Abstract]
Income from continuing operations before income taxes and noncontrolling interests	$ 3,429	$ 5,492	$ 5,486
Income tax benefits	426	901	928
Net income from continuing operations	3,003	4,591	4,558
Income from discontinued operations before taxes	5,777	988	942
Income taxes from discontinued operations	1,222	161	154
Net income from discontinued operations	4,555	827	788
Other comprehensive income (loss), after tax and net of reclassifications into Net income	1,971	1,524	(583)
Comprehensive income attributable to PNC	9,488	6,893	4,718
Discontinued Operations
Operating Expenses [Abstract]
Other comprehensive income (loss), after tax and net of reclassifications into Net income	115	4	(43)
Parent Company
Operating Revenues [Abstract]
Interest income	38	169	147
Noninterest income	37	48	(1)
Total operating revenue	14,076	3,957	2,942
Operating Expenses [Abstract]
Interest expense	179	325	281
Other expense	91	146	139
Total operating expense	270	471	420
Income before income taxes and equity in undistributed net income of subsidiaries	13,806	3,486	2,522
Equity in undistributed net income of subsidiaries:		1,363	2,307
Income from continuing operations before income taxes and noncontrolling interests	1,711	4,321	4,305
Income tax benefits	(1,251)	(221)	(208)
Net income from continuing operations	2,962	4,542	4,513
Income from discontinued operations before taxes	5,777	988	942
Income taxes from discontinued operations	1,222	161	154
Net income from discontinued operations	4,555	827	788
Net income	7,517	5,369	5,301
Net pension and other postretirement benefit plan activity arising during the period.	1	(2)	1
Other comprehensive income (loss), after tax and net of reclassifications into Net income	1	(2)	1
Comprehensive income attributable to PNC	7,518	5,367	5,302
Parent Company | Bank Subsidiaries And Bank Holding Company
Operating Revenues [Abstract]
Dividends from	13,701	3,570	2,639
Operating Expenses [Abstract]
Equity in undistributed net income of subsidiaries:	(12,009)	671	1,602
Parent Company | Bank Subsidiaries And Bank Holding Company | Discontinued Operations
Operating Revenues [Abstract]
Dividends from	126	460	418
Operating Expenses [Abstract]
Equity in undistributed net income of subsidiaries:	5,651	528	524
Parent Company | Non Bank Subsidiaries
Operating Revenues [Abstract]
Dividends from	300	170	157
Operating Expenses [Abstract]
Equity in undistributed net income of subsidiaries:	$ (86)	$ 164	$ 181