Credit Quality (Summarizes the Bancorp's Recorded Investment in Portfolio Loans and Leases by Age and Class) (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	$ 108,519	$ 94,487
Total Past Due	856	599
Total portfolio loans and leases	109,375	95,086
90-Days past Due and Still Accruing	130	93
30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	442	326
90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	414	273
Commercial Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due
Total portfolio loans and leases	69,958	59,571
Commercial Portfolio Segment [Member] | Commercial and Industrial Loans
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	50,305	44,213
Total Past Due	237	127
Total portfolio loans and leases	50,542	44,340
90-Days past Due and Still Accruing	11	4
Commercial Portfolio Segment [Member] | Commercial and Industrial Loans | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	133	32
Commercial Portfolio Segment [Member] | Commercial and Industrial Loans | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	104	95
Commercial Portfolio Segment [Member] | Commercial Mortgage Loans, Owner-Occupied
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	4,853	3,277
Total Past Due	27	7
Total portfolio loans and leases	4,880	3,284
90-Days past Due and Still Accruing	9	2
Commercial Portfolio Segment [Member] | Commercial Mortgage Loans, Owner-Occupied | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	4	1
Commercial Portfolio Segment [Member] | Commercial Mortgage Loans, Owner-Occupied | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	23	6
Commercial Portfolio Segment [Member] | Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	6,072	3,688
Total Past Due	11	2
Total portfolio loans and leases	6,083	3,690
90-Days past Due and Still Accruing	6	0
Commercial Portfolio Segment [Member] | Commercial Mortgage Loans, Nonowner-Occupied | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	5	1
Commercial Portfolio Segment [Member] | Commercial Mortgage Loans, Nonowner-Occupied | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	6	1
Commercial Portfolio Segment [Member] | Commercial Construction Loans
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	5,089	4,657
Total Past Due	1	0
Total portfolio loans and leases	5,090	4,657
90-Days past Due and Still Accruing	0	0
Commercial Portfolio Segment [Member] | Commercial Construction Loans | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	1	0
Commercial Portfolio Segment [Member] | Commercial Construction Loans | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	0	0
Commercial Portfolio Segment [Member] | Commercial Leases
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	3,338	3,597
Total Past Due	25	3
Total portfolio loans and leases	3,363	3,600
90-Days past Due and Still Accruing	0	0
Commercial Portfolio Segment [Member] | Commercial Leases | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	11	1
Commercial Portfolio Segment [Member] | Commercial Leases | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	14	2
Residential Mortgage
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	16,372	15,227
Total Past Due	169	98
Total portfolio loans and leases	16,541	15,325
90-Days past Due and Still Accruing	50	38
Residential Mortgage | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	27	37
Residential Mortgage | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	142	61
Consumer Portfolio Segment [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	5,965	6,280
Total Past Due	118	122
Total portfolio loans and leases	6,083	6,402
90-Days past Due and Still Accruing	1	0
Consumer Portfolio Segment [Member] | Home Equity Line of Credit [Member] | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	61	71
Consumer Portfolio Segment [Member] | Home Equity Line of Credit [Member] | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	57	51
Consumer Portfolio Segment [Member] | Indirect secured consumer loans
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	11,389	8,844
Total Past Due	149	132
Total portfolio loans and leases	11,538	8,976
90-Days past Due and Still Accruing	10	12
Consumer Portfolio Segment [Member] | Indirect secured consumer loans | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	132	119
Consumer Portfolio Segment [Member] | Indirect secured consumer loans | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	17	13
Consumer Portfolio Segment [Member] | Credit Card
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	2,434	2,381
Total Past Due	98	89
Total portfolio loans and leases	2,532	2,470
90-Days past Due and Still Accruing	42	37
Consumer Portfolio Segment [Member] | Credit Card | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	50	47
Consumer Portfolio Segment [Member] | Credit Card | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	48	42
Consumer Portfolio Segment [Member] | Other Consumer Loans
Financing Receivable, Recorded Investment, Past Due
Current Loans and Leases	2,702	2,323
Total Past Due	21	19
Total portfolio loans and leases	2,723	2,342
90-Days past Due and Still Accruing	1	0
Consumer Portfolio Segment [Member] | Other Consumer Loans | 30-89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	18	17
Consumer Portfolio Segment [Member] | Other Consumer Loans | 90 Days and Greater Past Due
Financing Receivable, Recorded Investment, Past Due
Total Past Due	$ 3	$ 2