Loans and Allowance for Loan Losses - Loans in Commercial Portfolio Segment Monitored for Credit Quality Revolving and Non Revolving Loans (Details) - USD ($) $ in Millions		Mar. 31, 2020	Dec. 31, 2019
Credit quality of consumer loans
Financing receivable	[1]	$ 89,786	$ 88,213
Commercial
Credit quality of consumer loans
2020		1,352
2019		7,806
2018		6,357
2017		3,795
2016		2,851
Prior		8,089
Revolving Loans		19,128
Financing receivable		49,378	$ 45,745
Commercial | Commercial and industrial
Credit quality of consumer loans
2020		722
2019		2,990
2018		2,245
2017		1,458
2016		882
Prior		2,579
Revolving Loans		18,996
Financing receivable		29,872
Commercial | Commercial and industrial | Pass
Credit quality of consumer loans
2020		673
2019		2,680
2018		2,090
2017		1,357
2016		873
Prior		2,372
Revolving Loans		17,905
Financing receivable		27,950
Commercial | Commercial and industrial | Special Mention
Credit quality of consumer loans
2020		49
2019		305
2018		84
2017		61
2016		9
Prior		135
Revolving Loans		594
Financing receivable		1,237
Commercial | Commercial and industrial | Classified
Credit quality of consumer loans
2020		0
2019		5
2018		71
2017		40
2016		0
Prior		72
Revolving Loans		497
Financing receivable		685
Commercial | Commercial Mortgage [Member]
Credit quality of consumer loans
2020		498
2019		3,928
2018		3,615
2017		2,043
2016		1,875
Prior		4,873
Revolving Loans		111
Financing receivable		16,943
Commercial | Commercial Mortgage [Member] | Pass
Credit quality of consumer loans
2020		498
2019		3,913
2018		3,577
2017		2,037
2016		1,869
Prior		4,508
Revolving Loans		111
Financing receivable		16,513
Commercial | Commercial Mortgage [Member] | Special Mention
Credit quality of consumer loans
2020		0
2019		13
2018		33
2017		2
2016		2
Prior		100
Revolving Loans		0
Financing receivable		150
Commercial | Commercial Mortgage [Member] | Classified
Credit quality of consumer loans
2020		0
2019		2
2018		5
2017		4
2016		4
Prior		265
Revolving Loans		0
Financing receivable		280
Commercial | Construction
Credit quality of consumer loans
2020		84
2019		620
2018		496
2017		293
2016		43
Prior		26
Revolving Loans		21
Financing receivable		1,583
Commercial | Construction | Pass
Credit quality of consumer loans
2020		84
2019		612
2018		427
2017		278
2016		35
Prior		0
Revolving Loans		21
Financing receivable		1,457
Commercial | Construction | Special Mention
Credit quality of consumer loans
2020		0
2019		4
2018		14
2017		2
2016		8
Prior		0
Revolving Loans		0
Financing receivable		28
Commercial | Construction | Classified
Credit quality of consumer loans
2020		0
2019		4
2018		55
2017		13
2016		0
Prior		26
Revolving Loans		0
Financing receivable		98
Commercial | Lease financing
Credit quality of consumer loans
2020		48
2019		268
2018		1
2017		1
2016		51
Prior		611
Revolving Loans		0
Financing receivable		980
Commercial | Lease financing | Pass
Credit quality of consumer loans
2020		48
2019		256
2018		1
2017		1
2016		51
Prior		522
Revolving Loans		0
Financing receivable		879
Commercial | Lease financing | Special Mention
Credit quality of consumer loans
2020		0
2019		0
2018		0
2017		0
2016		0
Prior		89
Revolving Loans		0
Financing receivable		89
Commercial | Lease financing | Classified
Credit quality of consumer loans
2020		0
2019		12
2018		0
2017		0
2016		0
Prior		0
Revolving Loans		0
Financing receivable		$ 12

[1] Includes $279 million and $320 million at March 31, 2020 and December 31, 2019, respectively, for net unamortized (discounts) and premiums and deferred (fees) and costs.Accrued interest receivable on loans held for investment and securities totaled $469 million at March 31, 2020 and is included in the other assets on the consolidated balance sheet.