Other Comprehensive Income (Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net Unrealized Gains Losses on Non Otti Securities [Abstract]
Increase in net unrealized gains(losses) on non-OTTI securities	$ 29	$ (329)	$ (494)
Less: Net gains (losses) realized as a yield adjustment reclassified to investment securities in interest income, before tax	25	24	27
Less: Net gains (losses) realized on sales of non-OTTI securities reclassified to noninterest income, before tax	(12)	16	48
Net unrealized gains (losses) on non-OTTI securities	16	(369)	(569)
Other Comprehensive Income (Loss), Non Otti Securities Adjustment, Tax	(6)	135	208
Net unrealized gains (losses) on non-OTTI securities, Activity, After Tax	10	(234)	(361)
Net Unrealized Gains Losses On Otti Securities [Abstract]
Increase in net unrealized gains (losses) on OTTI securities, Pretax	173	61	(17)
Less: Net gains (losses) realized on sales of securities reclassified to noninterest income	2
Less: Net OTTI losses realized in net income, Pre-tax	(1)	(2)	(4)
Net unrealized gains (losses) on OTTI securities	172	63	(13)
Net unrealized gains (losses) on OTTI securities, tax	(63)	(23)	5
Net unrealized gains (losses) on OTTI securities, Activity, After Tax	109	40	(8)
Net unrealized gains (losses) on cash flow hedge derivatives [Abstract]
Increase in net unrealized gains (losses) on cash flow hedge derivatives, Pretax	(90)	100	415
Less: Net gains (losses) realized as a yield adjustment reclassified to loan interest income, Before Tax	159	219	270
Less: Net gains (losses) realized as a yield adjustment reclassified to investment securities interest income, Before Tax	21	34	23
Less: Net gains (losses) realized on sales of securities reclassified to noninterest income, Before Tax	17		(5)
Net unrealized gains (losses) on cash flow hedge derivatives, Before Tax	(287)	(153)	127
Net unrealized gains (losses) on cash flow hedge derivatives, tax	105	56	(47)
Net unrealized gains (losses) on cash flow hedge derivatives, Net of tax, Total	(182)	(97)	80
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax [Abstract]
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment and Tax	126	(41)	(82)
Amortization of actuarial loss (gain) reclassified to other noninterest expense, Before tax	47	50	38
Amortization of prior service cost (credit) reclassified to other noninterest expense, Before tax	(4)	(8)	(10)
Pension and other postretirement benefit plan adjustments, net activity, Pre-Tax	169	1	(54)
Pension and other postretirement benefit plan adjustments, net activity, Tax	(62)		20
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	107	1	(34)
Other Comprehensive Income Other Adjustments [Abstract]
PNC's portion of BlackRock's OCI, Before tax	52	(63)	(39)
Net investment hedge derivatives, Before tax	(81)	186	60
Foreign Currency Transaction and Translation Adjustment, before Tax	90	(182)	(63)
Total Other, net activity, Before tax	61	(59)	(42)
Total Other, net activity, Tax	12	(46)	(8)
Total Other, net activity, After tax	73	(105)	(50)
Other Comprehensive Income (Loss), before Tax	131	(517)	(551)
Other Comprehensive Income (Loss), Tax	(14)	122	178
Other Comprehensive Income (Loss), Net of Tax	$ 117	$ (395)	$ (373)