KeyCorp (KEY) 10-K 25 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 18, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Entity Registrant Name	KEYCORP /NEW/
Trading Symbol	KEY
Entity Central Index Key	91,576
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		1,008,787,761
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 20,691,768,789
Entity Shell Company	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
ASSETS
Cash and due from banks		$ 678	$ 671
Short-term investments		2,562	4,447
Trading account assets		849	836
Securities available for sale		19,428	18,139
Held-to-maturity securities (fair value: $11,122 and $11,565)		11,519	11,830
Other investments		666	726
Loans, net of unearned income of $678 and $736		89,552	86,405
Allowance for loan and lease losses		(883)	(877)
Net loans		88,669	85,528
Loans held for sale	[1]	1,227	1,107
Premises and equipment		882	930
Operating lease assets		993	821
Goodwill		2,516	2,538
Other intangible assets		316	416
Corporate-owned life insurance		4,171	4,132
Accrued income and other assets		4,037	4,237
Discontinued assets		1,100	1,340
Total assets		139,613	137,698
Deposits in domestic offices:
NOW and money market deposit accounts		59,918	53,627
Savings deposits		4,854	6,296
Certificates of deposit ($100,000 or more)		7,913	6,849
Other time deposits		5,332	4,798
Total interest-bearing deposits		78,017	71,570
Noninterest-bearing deposits		29,292	33,665
Total deposits		107,309	105,235
Federal funds purchased and securities sold under repurchase agreements		319	377
Bank notes and other short-term borrowings		544	634
Accrued expense and other liabilities		2,113	2,094
Long-term debt		13,732	14,333
Total liabilities		124,017	122,673
EQUITY
Preferred stock		1,450	1,025
Common Shares, $1 par value; authorized 1,400,000,000 shares; issued 1,256,702,081 and 1,256,702,081 shares		1,257	1,257
Capital surplus		6,331	6,335
Retained earnings		11,556	10,335
Treasury stock, at cost (237,198,944 and 187,617,832 shares)		(4,181)	(3,150)
Accumulated other comprehensive income (loss)		(818)	(779)
Key shareholders’ equity		15,595	15,023
Noncontrolling interests		1	2
Total equity		15,596	15,025
Total liabilities and equity		$ 139,613	$ 137,698
[1]	Total loans held for sale include Real estate — residential mortgage loans held for sale at fair value of $54 million at December 31, 2018 , and $71 million at December 31, 2017

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Held-to-maturity securities, fair value	$ 11,122,000,000	$ 11,565,000,000
Unearned income on loans	678,000,000	736,000,000
Aggregate amount of certificates of deposit, denominations	$ 100,000	$ 100,000
Common shares, par value (in dollars per share)	$ 1	$ 1
Common shares, shares authorized (in shares)	1,400,000,000	1,400,000,000
Common shares, shares issued (in shares)	1,256,702,081	1,256,702,081
Treasury stock (in shares)	237,198,944	187,617,832
Residential Mortgage [Member]
Loans held for sale	$ 54,000,000	$ 71,000,000

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
INTEREST INCOME
Loans		$ 4,023	$ 3,677	$ 2,773
Loans held for sale		66	52	34
Securities available for sale		409	369	329
Held-to-maturity securities		284	222	122
Trading account assets		29	27	23
Short-term investments		46	26	22
Other investments		21	17	16
Total interest income		4,878	4,390	3,319
INTEREST EXPENSE
Deposits		517	278	171
Federal funds purchased and securities sold under repurchase agreements		11	1	1
Bank notes and other short-term borrowings		21	15	10
Long-term debt		420	319	218
Total interest expense		969	613	400
NET INTEREST INCOME		3,909	3,777	2,919
Provision for credit losses		246	229	266
Net interest income after provision for credit losses		3,663	3,548	2,653
NONINTEREST INCOME
Trust and investment services income		499	535	464
Investment banking and debt placement fees		650	603	482
Service charges on deposit accounts		349	357	302
Operating lease income and other leasing gains		89	96	62
Corporate services income		233	219	215
Cards and payments income		270	287	233
Corporate-owned life insurance income		137	131	125
Consumer mortgage income		30	26	17
Mortgage servicing fees		82	71	57
Other income	[1]	176	153	114
Total noninterest income		2,515	2,478	2,071
NONINTEREST EXPENSE
Personnel		2,309	2,278	2,048
Net occupancy		308	331	305
Computer processing		210	225	255
Business services and professional fees		184	192	235
Equipment		105	114	98
Operating lease expense		120	92	59
Marketing		102	120	101
FDIC assessment		72	82	61
Intangible asset amortization		99	95	55
OREO expense, net		6	11	9
Other expense		460	558	530
Total noninterest expense		3,975	4,098	3,756
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES		2,203	1,928	968
Income taxes		344	637	179
INCOME (LOSS) FROM CONTINUING OPERATIONS		1,859	1,291	789
Income (loss) from discontinued operations		7	7	1
NET INCOME (LOSS)		1,866	1,298	790
Less: Net income (loss) attributable to noncontrolling interests		0	2	(1)
NET INCOME (LOSS) ATTRIBUTABLE TO KEY		1,866	1,296	791
Income (loss) from continuing operations attributable to Key common shareholders		1,793	1,219	753
Net income (loss) attributable to Key common shareholders		$ 1,800	$ 1,226	$ 754
Per Common Share:
Income (loss) from continuing operations attributable to Key common shareholders (in dollars per share)		$ 1.72	$ 1.13	$ 0.81
Income (loss) from discontinued operations, net of taxes (in dollars per share)		0.01	0.01	0
Net income (loss) attributable to Key common shareholders (in dollars per share)	[2]	1.73	1.14	0.81
Per Common Share — assuming dilution:
Income (loss) from continuing operations attributable to Key common shareholders (in dollars per share)		1.70	1.12	0.80
Income (loss) from discontinued operations, net of taxes (in dollars per share)		0.01	0.01	0
Net income (loss) attributable to Key common shareholders (in dollars per share)	[2]	1.71	1.13	0.80
Cash dividends declared per common share (in dollars per share)		$ 0.565	$ 0.38	$ 0.33
Weighted-average common shares outstanding (000) (in shares)		1,040,890	1,072,078	927,816
Effect of convertible preferred stock (in shares)		0	0	0
Effect of common share options and other stock awards (in shares)		13,792	16,515	10,720
Weighted-average common shares and potential common shares outstanding (000) (in shares)	[3]	1,054,682	1,088,593	938,536
[1]	Net securities gains (losses) totaled less than $1 million for each of the years ended December 31, 2018 , 2017 , and 2016 . For 2018 , 2017 , and 2016
[2]	EPS may not foot due to rounding.
[3]	Assumes conversion of Common Share options and other stock awards and/or convertible preferred stock, as applicable.

Consolidated Statements of In_2

Consolidated Statements of Income (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Net securities gains (losses) (less than)	$ 0	$ 1,000,000	$ 0
Impairment losses related to securities	0	0	0
Other Noninterest Income [Member]
Net securities gains (losses) (less than)	$ 1,000,000	$ 1,000,000	$ 1,000,000

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 1,866	$ 1,298	$ 790
Other comprehensive income (loss), net of tax:
Net unrealized gains (losses) on securities available for sale, net of income taxes of ($19), $13, and (76)	(62)	(126)	(127)
Net unrealized gains (losses) on derivative financial instruments, net of income taxes of $11, ($19), and ($19)	36	(72)	(34)
Foreign currency translation adjustments, net of income taxes of $11, $9, and ($1)	(23)	12	(1)
Net pension and postretirement benefit costs, net of income taxes of $3, $80, and $19	10	(52)	26
Total other comprehensive income (loss), net of tax	(39)	(238)	(136)
Comprehensive income (loss)	1,827	1,060	654
Less: Comprehensive income attributable to noncontrolling interests	0	2	(1)
Comprehensive income (loss) attributable to Key	$ 1,827	$ 1,058	$ 655

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Income taxes effect on net unrealized (losses) gains on securities available for sale	$ (19)	$ 13	$ (76)
Income taxes effect net unrealized (losses) gains on derivative financial instruments	11	(19)	(19)
Income taxes effect on foreign currency translation adjustments	11	9	(1)
Income taxes effect on net pension and postretirement benefit costs	$ 3	$ 80	$ 19

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Series D Preferred Stock [Member]	Series E Preferred Stock [Member]	Series F Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Common Stock [Member]Series A Preferred Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Retained Earnings [Member]Series A Preferred Stock [Member]	Retained Earnings [Member]Series C Preferred Stock [Member]	Retained Earnings [Member]Series D Preferred Stock [Member]	Retained Earnings [Member]Series E Preferred Stock [Member]	Retained Earnings [Member]Series F Preferred Stock [Member]	Treasury Stock, at Cost [Member]	Treasury Stock, at Cost [Member]Series A Preferred Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interests [Member]
Beginning Balance, Preferred Shares (in shares) at Dec. 31, 2015					2,900,000
Beginning Balance, Common Shares (in shares) at Dec. 31, 2015						835,751,000
Beginning Balance at Dec. 31, 2015					$ 290	$ 1,017		$ 3,922	$ 8,922						$ (3,000)		$ (405)	$ 13
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 790								791									(1)
Other comprehensive income (loss)	(136)																(136)
Deferred compensation								(4)
Dividends, Cash [Abstract]
Cash dividends declared on common shares									(298)
Cash dividends declared on preferred stock										$ (22)	$ (8)	$ (7)
Common Shares issued for the acquisition of FNFG (in shares)						239,732,000
Common Shares issued for the acquisition of FNFG						$ 240		2,591
Common Shares repurchased (in shares)							(10,502,000)
Common Shares repurchased																$ (140)
Issuance of Preferred Stock (in shares)					14,521,000
Shares issued					$ 1,375			(16)
Redemption of Series C Preferred Stock	0
Common shares reissued (returned) for stock options and other employee benefit plans (in shares)						14,333,000
Common Shares reissued (returned) for stock options and other employee benefit plans								(108)							236
Net contribution from (distribution to) noncontrolling interests																		(12)
Ending Balance, Preferred Shares (in shares) at Dec. 31, 2016					17,421,000
Ending Balance, Common Shares (in shares) at Dec. 31, 2016						1,079,314,000
Ending Balance at Dec. 31, 2016					$ 1,665	$ 1,257		6,385	9,378						(2,904)		(541)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,298								1,296									2
Other comprehensive income (loss)	(238)																(238)
Reclassification of tax effects in AOCI resulting from the new federal corporate income tax rate	(141)								141
Deferred compensation								16
Dividends, Cash [Abstract]
Cash dividends declared on common shares									(410)
Cash dividends declared on preferred stock										$ (6)	$ (7)	(26)	$ (31)
Common Shares repurchased (in shares)						(36,140,000)
Common Shares repurchased															(665)
Series A Preferred Stock exchanged for common shares (in shares)					2,900,000	20,568,000
Series A Preferred Stock exchanged for Common Shares					$ (290)			(49)							338
Employee equity compensation program common share repurchases (in shares)						(3,520,000)
Employee equity compensation program Common Share repurchases															(65)
Redemption of Preferred Stock Series C (in shares)					(14,000,000)
Redemption of Series C Preferred Stock	350				$ (350)
Common shares reissued (returned) for stock options and other employee benefit plans (in shares)						8,862,000
Common Shares reissued (returned) for stock options and other employee benefit plans								(17)							146
Net contribution from (distribution to) noncontrolling interests																		0
Ending Balance, Preferred Shares (in shares) at Dec. 31, 2017					521,000
Ending Balance, Common Shares (in shares) at Dec. 31, 2017						1,069,084,000
Ending Balance at Dec. 31, 2017	15,025				$ 1,025	$ 1,257		6,335	10,335						(3,150)		(779)	2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other reclassification of AOCI	(13)								13
Net income (loss)	1,866								1,866									0
Other comprehensive income (loss)	(39)																(39)
Deferred compensation								21
Dividends, Cash [Abstract]
Cash dividends declared on common shares									(590)
Cash dividends declared on preferred stock												$ (26)	$ (31)	$ (9)
Common Shares repurchased (in shares)						(54,006,000)
Common Shares repurchased															(1,098)
Issuance of Preferred Stock (in shares)					425,000
Shares issued					$ 425			(13)
Employee equity compensation program common share repurchases (in shares)						(2,286,000)
Employee equity compensation program Common Share repurchases															(47)
Redemption of Series C Preferred Stock	0
Common shares reissued (returned) for stock options and other employee benefit plans (in shares)						6,711,000
Common Shares reissued (returned) for stock options and other employee benefit plans								(12)							114
Net contribution from (distribution to) noncontrolling interests																		(1)
Ending Balance, Preferred Shares (in shares) at Dec. 31, 2018		21,000	500,000	425,000	946,000
Ending Balance, Common Shares (in shares) at Dec. 31, 2018						1,019,503,000
Ending Balance at Dec. 31, 2018	$ 15,596				$ 1,450	$ 1,257		$ 6,331	$ 11,556						$ (4,181)		$ (818)	$ 1

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash dividends declared per common share (in dollars per share)	$ 0.565	$ 0.38	$ 0.33
Series A Preferred Stock [Member]
Cash dividends declared on Preferred Stock (in dollars per share)		1.9375	7.75
Series C Preferred Stock [Member]
Cash dividends declared on Preferred Stock (in dollars per share)		0.539063	0.539063
Series D Preferred Stock [Member]
Cash dividends declared on Preferred Stock (in dollars per share)	50	50	$ 13.33
Series E Preferred Stock [Member]
Cash dividends declared on Preferred Stock (in dollars per share)	1.531252	$ 1.544012
Series F Preferred Stock [Member]
Cash dividends declared on Preferred Stock (in dollars per share)	$ 0.529688

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
OPERATING ACTIVITIES
Net income (loss)	$ 1,866	$ 1,298	$ 790
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Provision for credit losses	246	229	266
Depreciation and amortization expense, net	382	407	314
Accretion of acquired loans	86	203	116
Increase in cash surrender value of corporate-owned life insurance	(117)	(119)	(111)
Stock-based compensation expense	99	100	99
FDIC reimbursement (payments), net of FDIC expense	(10)	(3)	13
Deferred income taxes (benefit)	98	303	11
Proceeds from sales of loans held for sale	14,019	11,963	8,572
Originations of loans held for sale, net of repayments	(13,948)	(11,846)	(8,361)
Net losses (gains) from sale of loans held for sale	(183)	(181)	(139)
Net losses (gains) and writedown on OREO	0	5	4
Net losses (gains) on leased equipment	41	3	7
Net losses (gains) on sales of fixed assets	9	24	56
Net securities losses (gains)	0	(1)	0
Net decrease (increase) in trading account assets	(13)	31	(79)
Gain on sale of KIBS	(83)	0	0
Direct acquisition costs	0	0	(44)
Other operating activities, net	14	(601)	175
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	2,506	1,815	1,689
INVESTING ACTIVITIES
Cash received (used) in acquisitions, net of cash acquired	0	(144)	(481)
Proceeds from sale of KIBS	124	0	0
Net decrease (increase) in short-term investments, excluding acquisitions	1,885	(1,672)	(68)
Purchases of securities available for sale	(4,594)	(3,002)	(5,718)
Proceeds from sales of securities available for sale	0	915	4,249
Proceeds from prepayments and maturities of securities available for sale	3,197	3,999	4,241
Proceeds from prepayments and maturities of held-to-maturity securities	1,558	1,797	1,627
Purchases of held-to-maturity securities	(1,242)	(3,398)	(6,968)
Purchases of other investments	(28)	(87)	(46)
Proceeds from sales of other investments	62	117	243
Proceeds from prepayments and maturities of other investments	40	4	4
Net decrease (increase) in loans, excluding acquisitions, sales, and transfers	(3,700)	(945)	(3,580)
Proceeds from sales of portfolio loans	204	183	140
Proceeds from corporate-owned life insurance	78	55	29
Purchases of premises, equipment, and software	(99)	(112)	(145)
Proceeds from sales of premises and equipment	2	0	0
Proceeds from sales of OREO	31	51	16
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(2,482)	(2,239)	(6,457)
FINANCING ACTIVITIES
Net increase (decrease) in deposits, excluding acquisitions	2,074	1,148	4,047
Net increase (decrease) in short-term borrowings	(148)	(1,299)	(1,294)
Net proceeds from issuance of long-term debt	2,306	2,852	2,827
Payments on long-term debt	(2,880)	(748)	(1,308)
Issuance of preferred shares	412	0	1,009
Repurchase of Common Shares	(1,098)	(664)	(140)
Employee equity compensation program Common Share repurchases	(47)	(66)	0
Redemption of Preferred Stock Series C	0	(350)	0
Net proceeds from reissuance of Common Shares	20	25	32
Cash dividends paid	(656)	(480)	(335)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(17)	418	4,838
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	7	(6)	70
CASH AND DUE FROM BANKS AT BEGINNING OF YEAR	671	677	607
CASH AND DUE FROM BANKS AT END OF YEAR	678	671	677
Additional disclosures relative to cash flows:
Interest paid	892	598	429
Income taxes paid (refunded)	12	6	144
Noncash items:
Reduction of secured borrowing and related collateral	20	40	67
Loans transferred to portfolio from held for sale	24	105	10
Loans transferred to held for sale from portfolio	(33)	42	45
Loans transferred to other real estate owned	25	37	36
CMBS risk retentions	16	18	0
First Niagara assets acquired	0	0	35,616
First Niagara liabilities assumed	0	0	33,028
Preferred Stock [Member]
Noncash items:
Common Shares issued for the acquisition of FNFG	0	0	350
Common Stock [Member]
Noncash items:
Common Shares issued for the acquisition of FNFG	$ 0	$ 0	$ 2,831

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1. Summary of Significant Accounting Policies Organization We are one of the nation’s largest bank-based financial services companies, providing deposit, lending, cash management, insurance, and investment services to individuals and small and medium-sized businesses through our subsidiary, KeyBank. We also provide a broad range of sophisticated corporate and investment banking products, such as merger and acquisition advice, public and private debt and equity, syndications, and derivatives to middle market companies in selected industries throughout the United States through our subsidiary, KBCM. As of December 31, 2018 , KeyBank operated 1,159 full-service retail banking branches and 1,505 ATMs in 15 states, as well as additional offices, online and mobile banking capabilities, and a telephone banking call center. Additional information pertaining to our two major business segments, Key Community Bank and Key Corporate Bank, is included in Note 24 (“ Line of Business Results ”). Use of Estimates Our accounting policies conform to GAAP and prevailing practices within the financial services industry. We must make certain estimates and judgments when determining the amounts presented in our consolidated financial statements and the related notes. If these estimates prove to be inaccurate, actual results could differ from those reported. Principles of Consolidation and Basis of Presentation The consolidated financial statements include the accounts of KeyCorp and its subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Some previously reported amounts have been reclassified to conform to current reporting practices. The consolidated financial statements also include the accounts of any voting rights entities in which we have a controlling financial interest and certain VIEs. In accordance with the applicable accounting guidance for consolidations, we consolidate a VIE if we have the power to direct activities of the VIE that most significantly impact the entity’s economic performance; and the obligation to absorb losses of the entity or the right to receive benefits from the entity that could potentially be significant to the VIE. See Note 12 (“ Variable Interest Entities ”) for information on our involvement with VIEs. We use the equity method to account for unconsolidated investments in voting rights entities or VIEs if we have significant influence over the entity’s operating and financing decisions (usually defined as a voting or economic interest of 20% to 50% , but not controlling). Unconsolidated investments in voting rights entities or VIEs in which we have a voting or economic interest of less than 20% generally are carried at fair value or a cost measurement alternative. In preparing these financial statements, subsequent events were evaluated through the time the financial statements were issued. Financial statements are considered issued when they are widely distributed to all shareholders and other financial statement users or filed with the SEC. Cash and Cash Equivalents Cash and due from banks are considered “cash and cash equivalents” for financial reporting purposes. We do not consider cash on deposit with the Federal Reserve to be restricted. Loans Loans held in portfolio, which management has the intent and ability to hold for the foreseeable future or until maturity or payoff, are carried at the principal amount outstanding, net of unearned income, including net deferred loan fees and costs and unamortized premiums and discounts. We defer certain nonrefundable loan origination and commitment fees, and the direct costs of originating or acquiring loans. The net deferred amount is amortized over the estimated lives of the related loans as an adjustment to the yield. Direct financing leases are carried at the aggregate of the lease receivable plus estimated unguaranteed residual values, less unearned income and deferred initial direct fees and costs. Unearned income on direct financing leases is amortized over the lease terms using a method approximating the interest method that produces a constant rate of return. Deferred initial direct fees and costs are amortized over the lease terms as an adjustment to the yield. The residual value component of a lease represents the fair value of the leased asset at the end of the lease term. We rely on industry data, historical experience, independent appraisals and the experience of the equipment leasing asset management team to value lease residuals. Relationships with a number of equipment vendors give the asset management team insight into the life cycle of the leased equipment, pending product upgrades and competing products. Residual values are reviewed at least annually to determine if an other-than-temporary decline in value has occurred. In the event of such a decline, the residual value is adjusted to its fair value. Impairment charges and net gains or losses on sales of lease residuals are included in “other income” on the income statement. Loans Held for Sale Loans held for sale generally include certain residential and commercial mortgage loans and other commercial loans. Loans are initially classified as held for sale when they are individually identified as being available for immediate sale and a formal plan exists to sell them. Loans held for sale are recorded at either fair value, if elected, or the lower of cost or fair value. Fair value is determined based on available market data for similar assets. When a loan is originated as held-for-sale, we do not defer the related fees and costs. Our commercial loans (including commercial mortgage and non-mortgage loans), which we originated and intend to sell, are carried at the lower of aggregate cost or fair value. Subsequent declines in fair value for loans held for sale are recognized as a charge to “other income” on the income statement. Consumer real estate - residential mortgages loans have been elected to be carried at fair value. Subsequent increases and decreases in fair value for loans elected to be measured at fair value are recorded to “consumer mortgage income” on the income statement. Additional information regarding fair value measurements associated with our loans held for sale is provided in Note 6 (“ Fair Value Measurements ”). We may transfer certain loans to held for sale at the lower of cost or fair value. If a loan is transferred from the loan portfolio to the held-for-sale category, any write-down in the carrying amount of the loan at the date of transfer is recorded as a reduction in the ALLL. When a loan is transferred into the held for sale category, we stop amortizing the related deferred fees and costs. The remaining unamortized fees and costs are recognized as part of the cost basis of the loan at the time it is sold. We may also transfer loans from held for sale to the loan portfolio held for investment. If a loan held for sale for which fair value accounting was elected is transferred to held for investment, it will continue to be accounted for at fair value in the loan portfolio. Nonperforming Loans Nonperforming loans are loans for which we do not accrue interest income, and include commercial and consumer loans and leases as well as current year TDRs and nonaccruing TDR loans from prior years. Nonperforming loans do not include loans held for sale or PCI loans. We generally classify commercial loans as nonperforming and stop accruing interest (i.e., designate the loan “nonaccrual”) when the borrower’s principal or interest payment is 90 days past due unless the loan is well-secured and in the process of collection. Commercial loans are also placed on nonaccrual status when payment is not past due but we have serious doubts about the borrower’s ability to comply with existing repayment terms. Once a loan is designated nonaccrual (and as a result assessed for impairment), the interest accrued but not collected is generally charged against the ALLL, and payments subsequently received are applied to principal. Commercial loans are typically charged off in full or charged down to the fair value of the underlying collateral when the borrower’s payment is 180 days past due. We classify consumer loans as nonperforming and stop accruing interest when the borrower’s payment is 120 days past due, unless the loan is well-secured and in the process of collection. Any second lien home equity loan with an associated first lien that is 120 days or more past due or in foreclosure, or for which the first mortgage delinquency timeframe is unknown, is reported as a nonperforming loan. Secured loans that are discharged through Chapter 7 bankruptcy and not formally re-affirmed are designated as nonperforming and TDRs. Our charge-off policy for most consumer loans takes effect when payments are 120 days past due. Home equity and residential mortgage loans generally are charged down to net realizable value when payment is 180 days past due. Credit card loans and similar unsecured products continue to accrue interest until the account is charged off at 180 days past due. Commercial and consumer loans may be returned to accrual status if we are reasonably assured that all contractually due principal and interest are collectible and the borrower has demonstrated a sustained period (generally six months ) of repayment performance under the contracted terms of the loan and applicable regulation. Impaired Loans A loan is considered to be impaired when, based on current information and events, it is probable that we will be unable to collect all amounts due (both principal and interest) according to the contractual terms of the loan agreement. All consumer TDRs, regardless of size, and all commercial TDRs and non-accrual commercial loans with an outstanding balance of $2.5 million or greater are individually evaluated for impairment and assigned a specific reserve. Commercial non-accrual loans of less than $2.5 million and all non-accrual consumer loans are aggregated and collectively evaluated for impairment. The amount of the reserve is estimated based on the criteria outlined in the “Allowance for Loan and Lease Losses” section of this note. Allowance for Loan and Lease Losses The ALLL represents our estimate of incurred credit losses inherent in the loan portfolio at the balance sheet date. We establish the amount of this allowance by analyzing the quality of the loan portfolio at least quarterly, and more often if deemed necessary. We segregate our loan portfolio between commercial and consumer loans and develop and document our methodology to determine the ALLL accordingly. We believe these portfolio segments represent the most appropriate level for determining our historical loss experience, as well as the level at which we monitor credit quality and risk characteristics of the portfolios. Commercial loans, which generally have larger individual balances, constitute a significant portion of our total loan portfolio. The consumer portfolio typically includes smaller-balance homogeneous loans. We estimate the appropriate level of our ALLL by applying expected loss rates to existing loans with similar risk characteristics. Expected loss rates for commercial loans are derived from a statistical analysis of our historical default and loss severity experience. The analysis utilizes probability of default and loss given default to assign loan grades using our internal risk rating system. Our expected loss rates are reviewed quarterly and updated as necessary. As of December 31, 2018 , the probability of default ratings was based on our default data for the period from January 2008 through October 2018, which encompasses the last downturn period as well as our more recent positive credit experience. We adjust expected loss rates based on calculated estimates of the average time period from initial loss indication to the initial loss recorded for an individual loan. Expected loss rates for consumer loans are statistically derived from an analysis of our historical default and loss severity experience, and is sensitive to change in delinquency status. Consumer loans are analyzed quarterly in homogeneous product-type pools that share similar risk attributes, including the application of delinquency roll rate models and credit loss severity estimates. Incurred losses that are not yet individually identifiable are measured as the estimate of the average time period for initial loss indication to initial loss recorded for consumer loans. The ALLL may be adjusted to reflect our current assessment of many qualitative factors that may not be directly measured in the statistical analysis of expected loss, including: • changes in international, national, regional, and local economic and business conditions; • changes in the experience, ability, and depth of our lending management and staff; • changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices; • changes in the nature and volume of the loan portfolio, including the existence and effect of any concentrations of credit, and changes in the level of such concentrations; • changes in the volume and/or severity of past due, nonaccrual, and adversely classified or graded loans; and • external factors, such as competition, legal developments, and regulatory requirements. For all consumer loan TDRs, regardless of size, as well as all commercial TDRs and non-accrual commercial loans with an outstanding balance of $2.5 million or greater, we conduct further analysis to determine the probable loss content and assign a specific allowance to the loan if deemed appropriate. We estimate the extent of the individual impairment for commercial loans and TDRs by comparing the recorded investment of the loan with the estimated present value of its future cash flows, the fair value of its underlying collateral, or the loan’s observable market price. Secured consumer loan TDRs that are discharged through Chapter 7 bankruptcy and not formally re-affirmed are adjusted to reflect the fair value of the underlying collateral, less costs to sell. Other consumer loan TDRs are assigned a specific allocation based on the estimated present value of future cash flows using the effective interest rate. A specific allowance also may be assigned — even when sources of repayment appear sufficient — if we remain uncertain about whether the loan will be repaid in full. On at least a quarterly basis, we evaluate the appropriateness of our loss estimation methods to reduce differences between estimated incurred losses and actual losses. Liability for Credit Losses on Lending-Related Commitments The liability for credit losses inherent in lending-related commitments, such as letters of credit and unfunded loan commitments, is included in “accrued expense and other liabilities” on the balance sheet and established through a charge to the provision for loan and lease losses. We determine the amount of this liability by considering both historical trends and current market conditions quarterly, or more often if deemed necessary. Fair Value Measurements Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between market participants in the principal market. Therefore, fair value represents an exit price at the measurement date. We value our assets and liabilities based on the principal or most advantageous market where each would be sold (in the case of assets) or transferred (in the case of liabilities). In the absence of observable market transactions, we consider liquidity valuation adjustments to reflect the uncertainty in pricing the instruments. Valuation inputs can be observable or unobservable. Observable inputs are assumptions based on market data obtained from an independent source. Unobservable inputs are assumptions based on our own information or assessment of assumptions used by other market participants in pricing the asset or liability. Our unobservable inputs are based on the best and most current information available on the measurement date. All inputs, whether observable or unobservable, are ranked in accordance with a prescribed fair value hierarchy that gives the highest ranking to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest ranking to unobservable inputs (Level 3). Fair values for Level 2 assets and liabilities are based on one or a combination of the following factors: (i) quoted market prices for similar assets or liabilities; (ii) observable inputs, such as interest rates or yield curves; or (iii) inputs derived principally from or corroborated by observable market data. The level in the fair value hierarchy ascribed to a fair value measurement in its entirety is based on the lowest level input that is significant to the measurement. We consider an input to be significant if it drives 10% or more of the total fair value of a particular asset or liability. Assets and liabilities may transfer between levels based on the observable and unobservable inputs used at the valuation date, as the inputs may be influenced by certain market conditions. We recognize transfers between levels of the fair value hierarchy at the end of the reporting period. Assets and liabilities are recorded at fair value on a recurring or non-recurring basis. Non-recurring fair value adjustments are typically recorded as a result of the application of lower of cost or fair value accounting; or impairment. At a minimum, we conduct our valuations quarterly. Additional information regarding fair value measurements and disclosures is provided in Note 6 (“ Fair Value Measurements ”). Short-Term Investments Short-term investments consist of segregated, interest-bearing deposits due from banks, the Federal Reserve, and certain non-U.S. banks as well as reverse repurchase agreements. Trading Account Assets Trading account assets are debt and equity securities, as well as commercial loans, that we purchase and hold but intend to sell in the near term. These assets are reported at fair value. Realized and unrealized gains and losses on trading account assets are reported in “other income” on the income statement. Securities Securities available for sale. Debt securities that we intend to hold for an indefinite period of time but that may be sold in response to changes in interest rates, prepayment risk, liquidity needs, or other factors are classified as available-for-sale and reported at fair value. Realized gains and losses resulting from sales of securities using the specific identification method, are included in “other income” on the income statement. Unrealized gains and losses (net of income taxes) deemed temporary are recorded in equity as a component of AOCI. Other-than-temporary unrealized losses on debt securities are included in “other income” on the income statement when the loss is attributable to credit. Other-than-temporary unrealized losses attributable to factors other than credit are recorded in AOCI. For additional information, refer to Note 7 (“ Securities ”). “Other securities” held in the available-for-sale portfolio consist of convertible preferred stock of privately held companies. Held-to-maturity securities. Debt securities that we have the intent and ability to hold until maturity are classified as held-to-maturity and are carried at cost and adjusted for amortization of premiums and accretion of discounts using the interest method. This method produces a constant rate of return on the adjusted carrying amount. “Other securities” held in the held-to-maturity portfolio consist of foreign bonds and capital securities. If any of the value of a held-to-maturity is determined to be unrecoverable, impairment will be recorded. Other Investments Other investments include equity and mezzanine instruments as well as other types of investments that generally are carried at the alternative cost method. The alternative cost method results in these investments being recorded at cost, less any impairment, plus or minus changes resulting from observable market transactions. Adjustments are included in “other income” on the income statement. Derivatives and Hedging All derivatives are recognized on the balance sheet at fair value in “accrued income and other assets” or “accrued expense and other liabilities”. The net increase or decrease in derivatives is included in “other operating activities, net” within the statement of cash flows. Accounting for changes in fair value (i.e., gains or losses) of derivatives differs depending on whether the derivative has been designated and qualifies as part of a hedge relationship, and on the type of hedge relationship. For derivatives that are not in a hedge relationship, any gain or loss, as well as any premium paid or received, is recognized immediately in earnings in “corporate services income” or “other income” on the income statement, depending whether the derivative is for customer accommodation or risk management, respectively. A derivative that is designated and qualifies as a hedging instrument must be designated as a fair value hedge, a cash flow hedge, or a hedge of a net investment in a foreign operation. Changes in the fair value of a hedging instrument are reflected in the same income statement line as the earnings effect of the hedged item. A fair value hedge is used to limit exposure to changes in the fair value of existing assets, liabilities, and commitments caused by changes in interest rates or other economic factors. The change in the fair value of an instrument designated as a fair value hedge is recorded in earnings at the same time as a change in fair value of the hedged risk. A cash flow hedge is used to minimize the variability of future cash flows that is caused by changes in interest rates or other economic factors. The gain or loss on a cash flow hedge is recorded as a component of AOCI on the balance sheet and reclassified to earnings in the same period in which the hedged transaction affects earnings (e.g., when we incur variable-rate interest on debt, earn variable-rate interest on loans, or sell commercial real estate loans). A net investment hedge is used to hedge the exposure of changes in the carrying value of investments as a result of changes in the related foreign exchange rates. The gain or loss on a net investment hedge is recorded as a component of AOCI on the balance sheet when the terms of the derivative match the notional and currency risk being hedged. The amount in AOCI is reclassified into income when the hedged transaction affects earnings (e.g., when we dispose or liquidate a foreign subsidiary). Hedge “effectiveness” is determined by the extent to which changes in the fair value of a derivative instrument offset changes in the fair value, cash flows, or carrying value attributable to the risk being hedged. If the relationship between the change in the fair value of the derivative instrument and the change in the hedged item falls within a range considered to be the industry norm, the hedge is considered “highly effective” and qualifies for hedge accounting. A hedge is “ineffective” if the relationship between the changes falls outside the acceptable range. In that case, hedge accounting is discontinued on a prospective basis. Hedge effectiveness is tested at least quarterly. We take into account the impact of bilateral collateral and master netting agreements that allow us to settle all derivative contracts held with a single counterparty on a net basis, and to offset the net derivative position with the related cash collateral when recognizing derivative assets and liabilities. As a result, we could have derivative contracts with negative fair values included in derivative assets on the balance sheet and contracts with positive fair values included in derivative liabilities. Derivative assets and derivative liabilities are recorded within “accrued income and other assets” and “accrued expense and other liabilities,” respectively. Additional information regarding the accounting for derivatives is provided in Note 8 (“ Derivatives and Hedging Activities ”). Servicing Assets We service commercial real estate and residential mortgages loans. Servicing assets and liabilities purchased or retained are initially measured at fair value and are recorded as a component of “accrued income and other assets” on the balance sheet. When no ready market value (such as quoted market prices, or prices based on sales or purchases of similar assets) is available to determine the fair value of servicing assets, fair value is determined by calculating the present value of future cash flows associated with servicing the loans. This calculation is based on a number of assumptions, including the market cost of servicing, the discount rate, the prepayment rate, and the default rate. We account for our servicing assets using the amortization method. The amortization of servicing assets is determined in proportion to, and over the period of, the estimated net servicing income and recorded in “mortgage servicing fees” on the income statement. Servicing assets are evaluated quarterly for possible impairment. This process involves stratifying the assets based upon one or more predominant risk characteristics and determining the fair value of each class. The characteristics may include financial asset type, size, interest rate, date of origination, term and geographic location. If the evaluation indicates that the carrying amount of the servicing assets exceeds their fair value, the carrying amount is reduced by recording a charge to income in the amount of such excess and establishing a valuation reserve allowance. Additional information pertaining to servicing assets is included in Note 9 (“ Mortgage Servicing Assets ”). Business Combinations We account for our business combinations using the acquisition method of accounting. Under this accounting method, the acquired company’s assets and liabilities are recorded at fair value at the date of acquisition, except as provided for by the applicable accounting guidance, and the results of operations of the acquired company are combined with Key’s results from the date of acquisition forward. Acquisition costs are expensed when incurred. The difference between the purchase price and the fair value of the net assets acquired (including identifiable intangible assets) is recorded as goodwill. Our accounting policy for intangible assets is summarized in this note under the heading “Goodwill and Other Intangible Assets.” Additional information regarding acquisitions is provided in Note 14 (“ Acquisitions, Divestiture, and Discontinued Operations ”). Goodwill and Other Intangible Assets Goodwill represents the amount by which the cost of net assets acquired in a business combination exceeds their f air value. Goodwill is assigned to reporting units as of the acquisition date based on the expected benefit to such reporting unit from the synergies of the business combination. Goodwill is not amortized. Goodwill is tested at the reporting unit level for impairment, at least annually as of October 1, or as events and circumstances change that would more-likely-than-not reduce the fair value of a reporting unit below its carrying amount. We may elect to perform a qualitative analysis to determine whether or not it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount. If we elect to bypass this qualitative analysis, or conclude via qualitative analysis that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value, a two-step goodwill impairment test is performed. In the first step, the fair value of each reporting unit is compared with its carrying value. If the fair value is greater than the carrying value, then the reporting unit's goodwill is deemed not to be impaired. If the fair value is less than the carrying value, then the second step is performed, which measures the amount of impairment by comparing the carrying amount of goodwill to its implied fair value. If the implied fair value of the goodwill exceeds the carrying amount, there is no impairment. If the carrying amount exceeds the implied fair value of the goodwill, an impairment charge is recorded for the excess. Other intangible assets with finite lives are amortized on either an accelerated or straight-line basis and are evaluated for impairment whenever events or circumstances indicate that the carrying value of the asset may not be recoverable . Additional information pertaining to goodwill and other intangible assets is included in Note 11 (“ Goodwill and Other Intangible Assets ”). Purchased Loans Purchased performing loans that do not have evidence of deterioration in credit quality at acquisition are recorded at fair value at the acquisition date. Any premium or discount associated with purchased performing loans is recognized as an expense or income based on the effective yield method of amortization for term loans or the straight-line method of amortization for revolving loans. Subsequent to the purchase date, the methods utilized to estimate the required ALLL for these loans is similar to originated loans; however, we record a provision for loan and lease losses only when the required ALLL exceeds any remaining purchase discount at the product level. Purchased loans that have evidence of deterioration in credit quality since origination and for which it is probable, at acquisition, that all contractually required payments will not be collected, are deemed PCI. Revolving loans, including lines of credit and credit card loans, leases, and loans where cash flows cannot be reasonably estimated are excluded from PCI accounting. Purchased loans are initially recorded at fair value without recording an allowance for loan losses. Fair value of these loans is determined using market participant assumptions in estimating the amount and timing of both principal and interest cash flows expected to be collected, as adjusted for an estimate of future credit losses and prepayments, and then a market-based discount rate is applied to those cash flows. PCI loans that have similar risk characteristics, primarily credit risk, collateral type and interest rate risk, and are homogeneous in size, are pooled and accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. PCI loans that cannot be aggregated into a pool are accounted for individually. The excess of cash flows expected to be collected, measured as of the acquisition date, over the estimated fair value is referred to as the “accretable yield” and is recognized in interest income over the remaining life of the loan or pool using the effective yield method. Accordingly, PCI loans are not subject to classification as nonaccrual (and nonperforming) in the same manner as originated loans. Rather, acquired PCI loans are considered to be accruing loans because their interest income relates to the accretable yield recognized on the individual loan or pool and not to the contractual interest payments of the loan. The difference between the contractually required principal and interest payments as of the acquisition date and the cash flows expected to be collected is referred to as the “nonaccretable difference.” The nonaccretable difference, which is not accreted into income, reflects estimated future credit losses and uncollectible contractual payments over the life of the PCI loan. After we acquire loans determined to be PCI loans, actual cash collections are monitored to determine if they conform to management’s expectations. Revised cash flow expectations are prepared each quarter. A decrease in expected cash flows in subsequent periods may indicate impairment and would require us to establish an ALLL by recording a charge to the provision for loan and lease losses. An increase in expected cash flows in subsequent periods initially reduces any previously established ALLL by the increase in the present value of cash flows expected to be collected, and requires us to recalculate the amount of accretable yield for the PCI loan or pool. The adjustment of accretable yield due to an increase in expected cash flows is accounted for as a change in estimate. The additional cash flows expected to be collected are reclassified from the nonaccretable difference to the accretable yield, and the amount of periodic accretion is adjusted accordingly over the remaining life of the PCI loan or pool. A PCI loan may be derecognized either through receipt of payment (i

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Common Share	2. Earnings Per Common Share Basic earnings per share is the amount of earnings (adjusted for dividends declared on our preferred stock) available to each Common Share outstanding during the reporting periods. Diluted earnings per share is the amount of earnings available to each Common Share outstanding during the reporting periods adjusted to include the effects of potentially dilutive Common Shares. Potentially dilutive Common Shares include stock options and other stock-based awards. Potentially dilutive Common Shares are excluded from the computation of diluted earnings per share in the periods where the effect would be antidilutive. Our basic and diluted earnings per Common Share are calculated as follows: Year ended December 31, dollars in millions, except per share amounts 2018 2017 2016 EARNINGS Income (loss) from continuing operations $ 1,859 $ 1,291 $ 789 Less: Net income (loss) attributable to noncontrolling interests — 2 (1 ) Income (loss) from continuing operations attributable to Key 1,859 1,289 790 Less: Dividends on preferred stock 66 70 37 Income (loss) from continuing operations attributable to Key common shareholders 1,793 1,219 753 Income (loss) from discontinued operations, net of taxes 7 7 1 Net income (loss) attributable to Key common shareholders $ 1,800 $ 1,226 $ 754 WEIGHTED-AVERAGE COMMON SHARES Weighted-average Common Shares outstanding (000) 1,040,890 1,072,078 927,816 Effect of common share options and other stock awards 13,792 16,515 10,720 Weighted-average common shares and potential Common Shares outstanding (000) (a) 1,054,682 1,088,593 938,536 EARNINGS PER COMMON SHARE Income (loss) from continuing operations attributable to Key common shareholders $ 1.72 $ 1.13 $ .81 Income (loss) from discontinued operations, net of taxes .01 .01 — Net income (loss) attributable to Key common shareholders (b) 1.73 1.14 .81 Income (loss) from continuing operations attributable to Key common shareholders — assuming dilution 1.70 1.12 .80 Income (loss) from discontinued operations, net of taxes .01 .01 — Net income (loss) attributable to Key common shareholders — assuming dilution (b) 1.71 1.13 .80 (a) Assumes conversion of Common Share options and other stock awards and/or convertible preferred stock, as applicable. (b)

Restrictions on Cash, Dividends

Restrictions on Cash, Dividends and Lending Activities	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Restrictions on Cash, Dividends, and Lending Activities	3. Restrictions on Cash, Dividends, and Lending Activities Federal law requires a depository institution to maintain a prescribed amount of cash or deposit reserve balances with its Federal Reserve Bank. KeyBank maintained average reserve balances aggregating $363 million in 2018 to fulfill these requirements. Currently KeyBank meets the required reserve balances with vault cash, therefore any cash on deposit at the Federal Reserve is not restricted. Capital distributions from KeyBank and other subsidiaries are our principal source of cash flows for paying dividends on our common and preferred shares, servicing our debt, and financing corporate operations. Federal banking law limits the amount of capital distributions that a bank can make to its holding company without prior regulatory approval. A national bank’s dividend-paying capacity is affected by several factors, including net profits (as defined by statute) for the previous two calendar years and for the current year, up to the date the dividend is declared. During 2018 , KeyBank paid $1.7 billion in dividends to KeyCorp. At January 1, 2019 , KeyBank had regulatory capacity to pay $1.0 billion in dividends to KeyCorp without prior regulatory approval. At December 31, 2018 , KeyCorp held $3.3 billion

Loan Portfolio

Loan Portfolio	12 Months Ended
	Dec. 31, 2018
Loans Receivables [Abstract]
Loan Portfolio	4. Loan Portfolio December 31, in millions 2018 2017 Commercial and industrial (a) $ 45,753 $ 41,859 Commercial real estate: Commercial mortgage 14,285 14,088 Construction 1,666 1,960 Total commercial real estate loans 15,951 16,048 Commercial lease financing (b) 4,606 4,826 Total commercial loans 66,310 62,733 Residential — prime loans: Real estate — residential mortgage 5,513 5,483 Home equity loans 11,142 12,028 Total residential — prime loans 16,655 17,511 Consumer direct loans 1,809 1,794 Credit cards 1,144 1,106 Consumer indirect loans 3,634 3,261 Total consumer loans 23,242 23,672 Total loans (c) $ 89,552 $ 86,405 (a) Loan balances include $132 million and $119 million of commercial credit card balances at December 31, 2018 , and December 31, 2017 , respectively. (b) Commercial lease financing includes receivables of $10 million and $24 million held as collateral for a secured borrowing at December 31, 2018 , and December 31, 2017 , respectively. Principal reductions are based on the cash payments received from these related receivables. Additional information pertaining to this secured borrowing is included in Note 19 (“ Long-Term Debt ”). (c) Total loans exclude loans in the amount of $1.1 billion at December 31, 2018 , and $1.3 billion at December 31, 2017 , related to the discontinued operations of the education lending business. Commercial lease financing receivables primarily are direct financing leases, but also include leveraged leases. The composition of the net investment in direct financing leases is as follows: December 31, in millions 2018 2017 Direct financing lease receivables $ 3,658 $ 3,727 Unearned income (345 ) (323 ) Unguaranteed residual value 412 382 Deferred fees and costs 19 19 Net investment in direct financing leases $ 3,744 $ 3,805 At December 31, 2018 , minimum future lease payments to be received are as follows: 2019 — $1 billion ; 2020 — $878 million ; 2021 — $609 million ; 2022 — $399 million ; 2023 — $238 million ; and all subsequent years — $416 million . The allowance related to lease financing receivables is $36 million at December 31, 2018

Asset Quality

Asset Quality	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Asset Quality	5. Asset Quality We assess the credit quality of the loan portfolio by monitoring net credit losses, levels of nonperforming assets and delinquencies, and credit quality ratings as defined by management. Credit Quality Indicators The prevalent risk characteristic for both commercial and consumer loans is the risk of loss arising from an obligor’s inability or failure to meet contractual payment or performance terms. Evaluation of this risk is stratified and monitored by the loan risk rating grades assigned for the commercial loan portfolios and the regulatory risk ratings assigned for the consumer loan portfolios. Most extensions of credit are subject to loan grading or scoring. Loan grades are assigned at the time of origination, verified by credit risk management, and periodically re-evaluated thereafter. This risk rating methodology blends our judgment with quantitative modeling. Commercial loans generally are assigned two internal risk ratings. The first rating reflects the probability that the borrower will default on an obligation; the second rating reflects expected recovery rates on the credit facility. Default probability is determined based on, among other factors, the financial strength of the borrower, an assessment of the borrower’s management, the borrower’s competitive position within its industry sector, and our view of industry risk in the context of the general economic outlook. Types of exposure, transaction structure, and collateral, including credit risk mitigants, affect the expected recovery assessment. Commercial Credit Exposure — Excluding PCI Credit Risk Profile by Creditworthiness Category (a), (b) December 31, in millions Commercial and industrial RE — Commercial RE — Construction Commercial Lease Total RATING 2018 2017 2018 2017 2018 2017 2018 2017 2018 2017 Pass $ 44,138 $ 39,833 $ 13,672 $ 13,328 $ 1,537 $ 1,894 $ 4,557 $ 4,730 $ 63,904 $ 59,785 Criticized (Accruing) 1,402 1,790 354 482 125 38 41 90 1,922 2,400 Criticized (Nonaccruing) 152 153 81 30 2 2 8 6 243 191 Total $ 45,692 $ 41,776 $ 14,107 $ 13,840 $ 1,664 $ 1,934 $ 4,606 $ 4,826 $ 66,069 $ 62,376 (a) Credit quality indicators are updated on an ongoing basis and reflect credit quality information as of the dates indicated. (b) The term criticized refers to those loans that are internally classified by Key as special mention or worse, which are asset quality categories defined by regulatory authorities. These assets have an elevated level of risk and may have a high probability of default or total loss. Pass rated refers to all loans not classified as criticized. Consumer Credit Exposure — Excluding PCI Non-PCI Loans by Refreshed FICO Score (a) December 31, in millions Residential — Prime Consumer direct loans Credit cards Consumer indirect loans Total FICO SCORE 2018 2017 2018 2017 2018 2017 2018 2017 2018 2017 750 and above $ 9,794 $ 10,226 $ 549 $ 519 $ 521 $ 477 $ 1,647 $ 1,472 $ 12,511 $ 12,694 660 to 749 4,906 5,181 700 690 507 508 1,320 1,184 7,433 7,563 Less than 660 1,411 1,519 224 225 116 121 565 529 2,316 2,394 No Score 213 208 333 356 — — 102 76 648 640 Total $ 16,324 $ 17,134 $ 1,806 $ 1,790 $ 1,144 $ 1,106 $ 3,634 $ 3,261 $ 22,908 $ 23,291 (a) Borrower FICO scores provide information about the credit quality of our consumer loan portfolio as they provide an indication as to the likelihood that a debtor will repay their debts. The scores are obtained from a nationally recognized consumer rating agency and are presented in the above table at the dates indicated. Commercial Credit Exposure — PCI Credit Risk Profile by Creditworthiness Category (a), (b) December 31, in millions Commercial and industrial RE — Commercial RE — Construction Commercial Lease Total RATING 2018 2017 2018 2017 2018 2017 2018 2017 2018 2017 Pass $ 37 $ 41 $ 125 $ 153 $ 2 $ 26 — — $ 164 $ 220 Criticized 24 42 53 95 — — — — 77 137 Total $ 61 $ 83 $ 178 $ 248 $ 2 $ 26 — — $ 241 $ 357 (a) Credit quality indicators are updated on an ongoing basis and reflect credit quality information as of the dates indicated. (b) The term criticized refers to those loans that are internally classified by Key as special mention or worse, which are asset quality categories defined by regulatory authorities. These assets have an elevated level of risk and may have a high probability of default or total loss. Pass rated refers to all loans not classified as criticized. Consumer Credit Exposure — PCI PCI Loans by Refreshed FICO Score (a) December 31, in millions Residential — Prime Consumer direct loans Credit cards Consumer indirect loans Total FICO SCORE 2018 2017 2018 2017 2018 2017 2018 2017 2018 2017 750 and above $ 137 $ 149 — — — — — — $ 137 $ 149 660 to 749 95 117 $ 1 $ 2 — — — — 96 119 Less than 660 97 105 2 2 — — — — 99 107 No Score 2 6 — — — — — — 2 6 Total $ 331 $ 377 $ 3 $ 4 — — — — $ 334 $ 381 (a) Borrower FICO scores provide information about the credit quality of our consumer loan portfolio as they provide an indication as to the likelihood that a debtor will repay their debts. The scores are obtained from a nationally recognized consumer rating agency and are presented in the above table at the dates indicated. Nonperforming and Past Due Loans Our policies for determining past due loans, placing loans on nonaccrual, applying payments on nonaccrual loans, and resuming accrual of interest for our commercial and consumer loan portfolios are disclosed in Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Nonperforming Loans.” The following aging analysis of current and past due loans as of December 31, 2018 , and December 31, 2017 , provides further information regarding Key’s credit exposure. Aging Analysis of Loan Portfolio (a) December 31, 2018 Current 30-59 Days Past Due (b) 60-89 Days Past Due (b) 90 and Greater Days Past Due (b) Non-performing Loans Total Past Due and Non-performing Loans Purchased Credit Impaired Total Loans (c), (d) in millions LOAN TYPE Commercial and industrial $ 45,375 $ 89 $ 31 $ 45 $ 152 $ 317 $ 61 $ 45,753 Commercial real estate: Commercial mortgage 13,957 27 17 25 81 150 178 14,285 Construction 1,646 — 13 3 2 18 2 1,666 Total commercial real estate loans 15,603 27 30 28 83 168 180 15,951 Commercial lease financing 4,580 12 1 4 9 26 — 4,606 Total commercial loans $ 65,558 $ 128 $ 62 $ 77 $ 244 $ 511 $ 241 $ 66,310 Real estate — residential mortgage $ 5,119 $ 11 $ 3 $ 4 $ 62 $ 80 $ 314 $ 5,513 Home equity loans 10,862 31 12 10 210 263 17 11,142 Consumer direct loans 1,780 11 5 6 4 26 3 1,809 Credit cards 1,119 6 5 12 2 25 — 1,144 Consumer indirect loans 3,573 31 7 3 20 61 — 3,634 Total consumer loans $ 22,453 $ 90 $ 32 $ 35 $ 298 $ 455 $ 334 $ 23,242 Total loans $ 88,011 $ 218 $ 94 $ 112 $ 542 $ 966 $ 575 $ 89,552 (a) Amounts in table represent recorded investment and exclude loans held for sale. Recorded investment represents the face amount of the loan increased or decreased by applicable accrued interest, net deferred loan fees and costs, and unamortized premium or discount, and reflects direct charge-offs. (b) Past due loan amounts exclude purchased impaired loans, even if contractually past due (or if we do not expect to collect principal or interest in full based on the original contractual terms), as we are currently accreting income over the remaining term of the loans. (c) Net of unearned income, net deferred loan fees and costs, and unamortized discounts and premiums. (d) Future accretable yield related to PCI loans is not included in the analysis of the loan portfolio. December 31, 2017 Current 30-59 Days Past Due (b) 60-89 Days Past Due (b) 90 and Greater Days Past Due (b) Non-performing Loans Total Past Due and Non-performing Loans Purchased Credit Impaired Total Loans (c), (d) in millions LOAN TYPE Commercial and industrial $ 41,444 $ 111 $ 34 $ 34 $ 153 $ 332 $ 83 $ 41,859 Commercial real estate: Commercial mortgage 13,750 26 13 21 30 90 248 14,088 Construction 1,919 4 9 — 2 15 26 1,960 Total commercial real estate loans 15,669 30 22 21 32 105 274 16,048 Commercial lease financing 4,791 23 4 2 6 35 — 4,826 Total commercial loans $ 61,904 $ 164 $ 60 $ 57 $ 191 $ 472 $ 357 $ 62,733 Real estate — residential mortgage $ 5,043 $ 16 $ 7 $ 4 $ 58 $ 85 $ 355 $ 5,483 Home equity loans 11,721 32 15 9 229 285 22 12,028 Consumer direct loans 1,768 9 4 5 4 22 4 1,794 Credit cards 1,081 7 5 11 2 25 — 1,106 Consumer indirect loans 3,199 33 7 3 19 62 — 3,261 Total consumer loans $ 22,812 $ 97 $ 38 $ 32 $ 312 $ 479 $ 381 $ 23,672 Total loans $ 84,716 $ 261 $ 98 $ 89 $ 503 $ 951 $ 738 $ 86,405 (a) Amounts in table represent recorded investment and exclude loans held for sale. Recorded investment represents the face amount of the loan increased or decreased by applicable accrued interest, net deferred loan fees and costs, and unamortized premium or discount, and reflects direct charge-offs. (b) Past due loan amounts exclude purchased impaired loans, even if contractually past due (or if we do not expect to collect principal or interest in full based on the original contractual terms), as we are currently accreting income over the remaining term of the loans. (c) Net of unearned income, net deferred loan fees and costs, and unamortized discounts and premiums. (d) Future accretable yield related to PCI loans is not included in the analysis of the loan portfolio. At December 31, 2018 , the approximate carrying amount of our commercial nonperforming loans outstanding represented 75% of their original contractual amount owed, total nonperforming loans outstanding represented 80% of their original contractual amount owed, and nonperforming assets in total were carried at 81% of their original contractual amount owed. Nonperforming loans reduced expected interest income by $30 million , $25 million , and $26 million for each of the twelve months ended December 31, 2018 , December 31, 2017 , and December 31, 2016 , respectively. The following tables set forth a further breakdown of individually impaired loans: December 31, 2018 December 31, 2017 Recorded Investment (a) Unpaid Principal Balance (b) Specific Allowance (c) Recorded Investment (a) Unpaid Principal Balance (b) Specific Allowance (c) in millions With no related allowance recorded: Commercial and industrial $ 118 $ 175 — $ 126 $ 153 — Commercial real estate: Commercial mortgage 64 70 — 12 18 — Total commercial real estate loans 64 70 — 12 18 — Total commercial loans 182 245 — 138 171 — Real estate — residential mortgage 4 5 — 17 17 — Home equity loans 49 56 — 56 56 — Consumer direct loans 1 1 — — — — Consumer indirect loans 2 4 — 2 2 — Total consumer loans 56 66 — 75 75 — Total loans with no related allowance recorded 238 311 — 213 246 — With an allowance recorded: Commercial and industrial 44 47 $ 5 10 28 $ 6 Commercial real estate: Commercial mortgage 2 3 1 — — — Total commercial real estate loans 2 3 1 — — — Total commercial loans 46 50 6 10 28 6 Real estate — residential mortgage 45 70 3 32 32 5 Home equity loans 78 85 8 61 61 9 Consumer direct loans 3 3 — 4 4 — Credit cards 3 3 — 2 2 — Consumer indirect loans 34 34 2 32 32 3 Total consumer loans 163 195 13 131 131 17 Total loans with an allowance recorded 209 245 19 141 159 23 Total $ 447 $ 556 $ 19 $ 354 $ 405 $ 23 (a) The Recorded Investment represents the face amount of the loan increased or decreased by applicable accrued interest, net deferred loan fees and costs, and unamortized premium or discount, and reflects direct charge-offs. This amount is a component of total loans on our consolidated balance sheet. (b) The Unpaid Principal Balance represents the customer’s legal obligation to us. (c) See Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Impaired Loans” for a description of the specific allowance methodology. The following table sets forth a further breakdown of average individually impaired loans reported by Key: Average Recorded Investment (a) Twelve Months Ended December 31, in millions 2018 2017 2016 Commercial and industrial $ 149 $ 210 $ 176 Commercial real estate: Commercial mortgage 39 9 8 Construction — — 3 Total commercial real estate loans 39 9 11 Total commercial loans 188 219 187 Real estate — residential mortgage 49 50 53 Home equity loans 122 121 125 Consumer direct loans 4 3 3 Credit cards 3 3 3 Consumer indirect loans 35 32 34 Total consumer loans 213 209 218 Total $ 401 $ 428 $ 405 (a) The Recorded Investment represents the face amount of the loan increased or decreased by applicable accrued interest, net deferred loan fees and costs, and unamortized premium or discount, and reflects direct charge-offs. This amount is a component of total loans on our consolidated balance sheet. For the twelve months ended December 31, 2018 , December 31, 2017 , and December 31, 2016 , interest income recognized on the outstanding balances of accruing impaired loans totaled $13 million , $9 million , and $10 million , respectively. TDRs We classify loan modifications as TDRs when a borrower is experiencing financial difficulties and we have granted a concession without commensurate financial, structural, or legal consideration. Acquired loans that were previously modified by First Niagara in a TDR are no longer classified as TDRs at the Acquisition Date. An acquired loan may only be classified as a TDR if a modification meeting the above TDR criteria is performed after the Acquisition Date. PCI loans cannot be classified as TDRs. All commercial and consumer loan TDRs, regardless of size, are individually evaluated for impairment to determine the probable loss content and are assigned a specific loan allowance. This designation has the effect of moving the loan from the general reserve methodology (i.e., collectively evaluated) to the specific reserve methodology (i.e., individually evaluated) and may impact the ALLL through a charge-off or increased loan loss provision. These components affect the ultimate allowance level. As TDRs are individually evaluated for impairment under the specific reserve methodology, subsequent defaults do not generally have a significant additional impact on the ALLL. Commitments outstanding to lend additional funds to borrowers whose loan terms have been modified in TDRs are $5 million and $2 million at December 31, 2018 , and December 31, 2017 , respectively. Our loan modifications are handled on a case-by-case basis and are negotiated to achieve mutually agreeable terms that maximize loan collectability and meet the borrower’s financial needs. The consumer TDR other concession category primarily includes those borrowers’ debts that are discharged through Chapter 7 bankruptcy and have not been formally re-affirmed. At December 31, 2018 , and December 31, 2017 , the recorded investment of loans secured by residential real estate in the process of foreclosure was approximately $113 million and $142 million , respectively. At December 31, 2018 , and December 31, 2017 , we had $35 million and $31 million , respectively, of OREO which included the carrying value of foreclosed residential real estate of approximately $35 million and $26 million , respectively. The following table shows the period-end post-modification outstanding recorded investment by concession type for our commercial and consumer accruing and nonaccruing TDRs added during the periods indicated: Twelve Months Ended December 31, in millions 2018 2017 Commercial loans: Extension of maturity date $ 15 12 Payment or covenant modification/deferment 99 $ 46 Bankruptcy plan modification 7 31 Total $ 121 $ 89 Consumer loans: Interest rate reduction $ 27 $ 13 Forgiveness of principal — — Other 38 28 Total $ 65 $ 41 Total commercial and consumer TDRs $ 186 $ 130 The following table summarizes the change in the post-modification outstanding recorded investment of our accruing and nonaccruing TDRs during the periods indicated: Year ended December 31, in millions 2018 2017 Balance at beginning of the period $ 317 $ 280 Additions 228 165 Payments (110 ) (111 ) Charge-offs (36 ) (17 ) Balance at end of period (a) $ 399 $ 317 A further breakdown of TDRs included in nonperforming loans by loan category for the periods indicated are as follows: December 31, 2018 December 31, 2017 Number of Loans Pre-modification Outstanding Recorded Investment Post-modification Outstanding Recorded Investment Number Pre-modification Post-modification dollars in millions LOAN TYPE Nonperforming: Commercial and industrial 35 $ 121 $ 85 20 $ 109 $ 86 Commercial real estate: Real estate — commercial mortgage 6 66 62 8 16 12 Total commercial real estate loans 6 66 62 8 16 12 Total commercial loans 41 187 147 28 125 98 Real estate — residential mortgage 281 21 20 308 18 18 Home equity loans 1,142 66 63 1,025 64 57 Consumer direct loans 171 2 1 114 2 2 Credit cards 330 2 2 322 2 1 Consumer indirect loans 1,098 18 14 825 16 13 Total consumer loans 3,022 109 100 2,594 102 91 Total nonperforming TDRs 3,063 296 247 2,622 227 189 Prior-year accruing: (a) Commercial and industrial 11 37 32 4 30 13 Commercial real estate: Real estate — commercial mortgage 2 — — — — — Total commercial loans 13 37 32 4 30 13 Real estate — residential mortgage 491 36 30 484 31 31 Home equity loans 1,403 82 64 1,276 75 59 Consumer direct loans 79 4 3 48 3 2 Credit cards 479 3 1 430 1 1 Consumer indirect loans 556 33 22 320 31 22 Total consumer loans 3,008 158 120 2,558 141 115 Total prior-year accruing TDRs 3,021 195 152 2,562 171 128 Total TDRs 6,084 $ 491 $ 399 5,184 $ 398 $ 317 (a) All TDRs that were restructured prior to January 1, 2018 , and January 1, 2017 , are fully accruing. Commercial loan TDRs are considered defaulted when principal and interest payments are 90 days past due. Consumer loan TDRs are considered defaulted when principal and interest payments are more than 60 days past due. During the year ended December 31, 2018 , there was one commercial loan TDR and 253 consumer loan TDRs with a combined recorded investment of $11 million that experienced payment defaults after modifications resulting in TDR status during 2017 . During the year ended December 31, 2017 , there were no commercial loan TDRs and 147 consumer loan TDRs with a combined recorded investment of $4 million that experienced payment defaults after modifications resulting in TDR status during 2016 . During the year ended December 31, 2016 , there were no commercial loan TDRs and 187 consumer loan TDRs with a combined recorded investment of $9 million that experienced payment defaults after modifications resulting in TDR status during 2015 . ALLL and Liability for Credit Losses on Unfunded Lending-Related Commitments We determine the appropriate level of the ALLL on at least a quarterly basis. The methodology is described in Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Allowance for Loan and Lease Losses.” The ALLL on the acquired non-impaired loan portfolio is estimated using the same methodology as the originated portfolio, however, the estimated ALLL is compared to the remaining accretable yield to determine if an ALLL must be recorded. For PCI loans, Key estimates cash flows expected to be collected quarterly. Decreases in expected cash flows are recognized as impairment through a provision for loan and lease losses and an increase in the ALLL. There was a benefit of $2 million of provision for loan and lease losses on these PCI loans during the year ended December 31, 2018 . There was $3 million of provision for loan and lease losses on these PCI loans during the year ended December 31, 2017 . The changes in the ALLL by loan category for the periods indicated are as follows: in millions December 31, 2017 Provision Charge-offs Recoveries December 31, 2018 Commercial and industrial $ 529 $ 125 $ (159 ) $ 37 $ 532 Real estate — commercial mortgage 133 27 (21 ) 3 142 Real estate — construction 30 1 — 2 33 Commercial lease financing 43 (2 ) (10 ) 5 36 Total commercial loans 735 151 (190 ) 47 743 Real estate — residential mortgage 7 1 (3 ) 2 7 Home equity loans 43 2 (21 ) 11 35 Consumer direct loans 28 31 (36 ) 7 30 Credit cards 44 41 (44 ) 7 48 Consumer indirect loans 20 14 (30 ) 16 20 Total consumer loans 142 89 (134 ) 43 140 Total ALLL — continuing operations 877 240 (a) (324 ) 90 883 Discontinued operations 16 8 (15 ) 5 14 Total ALLL — including discontinued operations $ 893 $ 248 $ (339 ) $ 95 $ 897 (a) Excludes a provision for losses on lending-related commitments of $6 million . in millions December 31, 2016 Provision Charge-offs Recoveries December 31, 2017 Commercial and industrial $ 508 $ 114 $ (133 ) $ 40 $ 529 Real estate — commercial mortgage 144 (2 ) (11 ) 2 133 Real estate — construction 22 9 (2 ) 1 30 Commercial lease financing 42 9 (14 ) 6 43 Total commercial loans 716 130 (160 ) 49 735 Real estate — residential mortgage 17 (11 ) (3 ) 4 7 Home equity loans 54 4 (30 ) 15 43 Consumer direct loans 24 32 (34 ) 6 28 Credit cards 38 45 (44 ) 5 44 Consumer indirect loans 9 27 (31 ) 15 20 Total consumer loans 142 97 (142 ) 45 142 Total ALLL — continuing operations 858 227 (a) (302 ) 94 877 Discontinued operations 24 10 (26 ) 8 16 Total ALLL — including discontinued operations $ 882 $ 237 $ (328 ) $ 102 $ 893 (a) Excludes a provision for losses on lending-related commitments of $2 million . in millions December 31, 2015 Provision Charge-offs Recoveries December 31, 2016 Commercial and industrial $ 450 $ 165 $ (118 ) $ 11 $ 508 Real estate — commercial mortgage 134 6 (5 ) 9 144 Real estate — construction 25 4 (9 ) 2 22 Commercial lease financing 47 4 (12 ) 3 42 Total commercial loans 656 179 (144 ) 25 716 Real estate — residential mortgage 18 2 (4 ) 1 17 Home equity loans 57 13 (30 ) 14 54 Consumer direct loans 20 26 (27 ) 5 24 Credit cards 32 37 (35 ) 4 38 Consumer indirect loans 13 10 (21 ) 7 9 Total consumer loans 140 88 (117 ) 31 142 Total ALLL — continuing operations 796 267 (a) (261 ) 56 858 Discontinued operations 28 13 (28 ) 11 24 Total ALLL — including discontinued operations $ 824 $ 280 $ (289 ) $ 67 $ 882 (a) Excludes a credit for losses on lending-related commitments of $1 million . A breakdown of the individual and collective ALLL and the corresponding loan balances for the periods indicated are as follows: Allowance Outstanding December 31, 2018 Individually Evaluated for Impairment Collectively Evaluated for Impairment Purchased Credit Impaired Loans Individually Evaluated for Impairment Collectively Evaluated for Impairment Purchased Credit Impaired in millions Commercial and industrial $ 5 $ 526 $ 1 $ 45,753 $ 162 $ 45,530 $ 61 Commercial real estate: Commercial mortgage — 139 3 14,285 66 14,041 178 Construction — 33 — 1,666 — 1,664 2 Total commercial real estate loans — 172 3 15,951 66 15,705 180 Commercial lease financing — 36 — 4,606 — 4,606 — Total commercial loans 5 734 4 66,310 228 65,841 241 Real estate — residential mortgage 3 4 — 5,513 49 5,150 314 Home equity loans 8 26 1 11,142 127 10,998 17 Consumer direct loans — 30 — 1,809 4 1,802 3 Credit cards — 48 — 1,144 3 1,141 — Consumer indirect loans 3 17 — 3,634 36 3,598 — Total consumer loans 14 125 1 23,242 219 22,689 334 Total ALLL — continuing operations 19 859 5 89,552 447 88,530 575 Discontinued operations 2 12 — 1,073 (a) 23 1,050 (a) — Total ALLL — including discontinued operations $ 21 $ 871 $ 5 $ 90,625 $ 470 $ 89,580 $ 575 (a) Amount includes $2 million of loans carried at fair value that are excluded from ALLL consideration. Allowance Outstanding December 31, 2017 Individually Evaluated for Impairment Collectively Evaluated for Impairment Purchased Credit Impaired Loans Individually Evaluated for Impairment Collectively Evaluated for Impairment Purchased Credit Impaired in millions Commercial and industrial $ 6 $ 520 $ 3 $ 41,859 $ 136 $ 41,640 $ 83 Commercial real estate: Commercial mortgage — 131 2 14,088 12 13,828 248 Construction — 30 — 1,960 — 1,934 26 Total commercial real estate loans — 161 2 16,048 12 15,762 274 Commercial lease financing — 43 — 4,826 — 4,826 — Total commercial loans 6 724 5 62,733 148 62,228 357 Real estate — residential mortgage 5 2 — 5,483 49 5,079 355 Home equity loans 9 33 1 12,028 117 11,889 22 Consumer direct loans — 28 — 1,794 4 1,786 4 Credit cards — 44 — 1,106 2 1,104 — Consumer indirect loans 3 17 — 3,261 34 3,227 — Total consumer loans 17 124 1 23,672 206 23,085 381 Total ALLL — continuing operations 23 848 6 86,405 354 85,313 738 Discontinued operations 3 13 — 1,314 (a) 21 1,293 (a) — Total ALLL — including discontinued operations $ 26 $ 861 $ 6 $ 87,719 $ 375 $ 86,606 $ 738 (a) Amount includes $2 million of loans carried at fair value that are excluded from ALLL consideration. The liability for credit losses inherent in lending-related unfunded commitments, such as letters of credit and unfunded loan commitments, is included in “accrued expense and other liabilities” on the balance sheet. We establish the amount of this reserve by considering both historical trends and current market conditions quarterly, or more often if deemed necessary. Changes in the liability for credit losses on unfunded lending-related commitments are summarized as follows: Year ended December 31, in millions 2018 2017 2016 Balance at beginning of period $ 57 $ 55 $ 56 Provision (credit) for losses on lending-related commitments 6 2 (1 ) Balance at end of period $ 63 $ 57 $ 55 PCI Loans Purchased loans that have evidence of deterioration in credit quality since origination and for which it is probable, at acquisition, that all contractually required payments will not be collected are deemed PCI. Our policies for determining, recording payments on, and derecognizing PCI loans are disclosed in Note 1 ( Summary of Significant Accounting Policies ) under the heading “Purchases Loans.” We have PCI loans from two separate acquisitions, one in 2012 and one in 2016. The following tables present the rollforward of the accretable yield and the beginning and ending outstanding unpaid principal balance and carrying amount of all PCI loans for the for the periods indicated: Twelve Months Ended December 31, 2018 2017 in millions Accretable Yield Carrying Amount Outstanding Unpaid Principal Balance Accretable Yield Carrying Amount Outstanding Unpaid Principal Balance Balance at beginning of period $ 131 $ 738 $ 803 $ 197 $ 865 $ 1,002 Additions — (32 ) Accretion (42 ) (44 ) Net reclassifications from non-accretable to accretable 50 15 Payments received, net (21 ) (4 ) Disposals — (1 ) Loans charged off (1 ) — Balance at end of period $ 117 $ 571 $ 607 $ 131 $ 738 $ 803

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	6. Fair Value Measurements In accordance with GAAP, Key measures certain assets and liabilities at fair value. Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between market participants in our principal market. Additional information regarding our accounting policies for determining fair value is provided in Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Fair Value Measurements.” Assets and Liabilities Measured at Fair Value on a Recurring Basis The following tables present assets and liabilities measured at fair value on a recurring basis at December 31, 2018 , and December 31, 2017 . December 31, 2018 December 31, 2017 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total in millions ASSETS MEASURED ON A RECURRING BASIS Trading account assets: U.S. Treasury, agencies and corporations — $ 578 — $ 578 — $ 615 — $ 615 States and political subdivisions — 60 — 60 — 37 — 37 Other mortgage-backed securities — 164 — 164 — 104 — 104 Other securities — 22 — 22 — 65 — 65 Total trading account securities — 824 — 824 — 821 — 821 Commercial loans — 25 — 25 — 15 — 15 Total trading account assets — 849 — 849 — 836 — 836 Securities available for sale: U.S. Treasury, agencies and corporations — 147 — 147 — 157 — 157 States and political subdivisions — 7 — 7 — 9 — 9 Agency residential collateralized mortgage obligations — 13,962 — 13,962 — 14,660 — 14,660 Agency residential mortgage-backed securities — 2,105 — 2,105 — 1,439 — 1,439 Agency commercial mortgage-backed securities — 3,187 — 3,187 — 1,854 — 1,854 Other securities — — $ 20 20 — — $ 20 20 Total securities available for sale — 19,408 20 19,428 — 18,119 20 18,139 Other investments: Principal investments: Direct — — 1 1 — — 13 13 Indirect (measured at NAV) (a) — — — 96 — — — 124 Total principal investments — — 1 97 — — 13 137 Equity investments: Direct — 1 7 8 — 4 3 7 Direct (measured at NAV) (a) — — — 1 — — — — Indirect (measured at NAV) (a) — — — 9 — — — — Total equity investments — 1 7 18 — 4 3 7 Total other investments — 1 8 115 — 4 16 144 Loans, net of unearned income (residential) — — 3 3 — — 2 2 Loans held for sale (residential) — 54 — 54 — 70 1 71 Derivative assets: Interest rate — 410 5 415 — 713 9 722 Foreign exchange $ 70 36 — 106 $ 100 $ 30 $ — $ 130 Commodity — 333 — 333 — 255 — 255 Credit — 1 — 1 — — 1 1 Other — 6 3 9 — 1 3 4 Derivative assets 70 786 8 864 100 999 13 1,112 Netting adjustments (b) — — — (333 ) — — — (443 ) Total derivative assets 70 786 8 531 100 999 13 669 Total assets on a recurring basis at fair value $ 70 $ 21,098 $ 39 $ 20,980 $ 100 $ 20,028 $ 52 $ 19,861 LIABILITIES MEASURED ON A RECURRING BASIS Bank notes and other short-term borrowings: Short positions $ 14 $ 530 — $ 544 $ 72 $ 562 — $ 634 Derivative liabilities: Interest rate — 297 — 297 — 520 — 520 Foreign exchange 58 37 — 95 98 26 — 124 Commodity — 323 — 323 — 246 — 246 Credit — 1 — 1 — 4 — 4 Other — 7 — 7 — 13 — 13 Derivative liabilities 58 665 — 723 98 809 — 907 Netting adjustments (b) — — — (337 ) — — — (616 ) Total derivative liabilities 58 665 — 386 98 809 — 291 Total liabilities on a recurring basis at fair value $ 72 $ 1,195 — $ 930 $ 170 $ 1,371 — $ 925 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheet. (b) Netting adjustments represent the amounts recorded to convert our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. The net basis takes into account the impact of bilateral collateral and master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Total derivative assets and liabilities include these netting adjustments. Qualitative Disclosures of Valuation Techniques The following table describes the valuation techniques and significant inputs used to measure the classes of assets and liabilities reported at fair value on a recurring basis, as well as the classification of each within the valuation hierarchy. Asset/liability class Valuation technique Valuation hierarchy classification(s) Securities (trading account assets and available for sale) Fair value of level 1 securities is determined by: • Quoted market prices available in an active market for identical securities. This includes exchange-traded equity securities. Fair value of level 2 securities is determined by: • Pricing models (either by a third party pricing service or internally). Inputs include: yields, benchmark securities, bids, offers, actual trade data (i.e., spreads, credit ratings, and interest rates) for comparable assets, spread tables, matrices, high-grade scales, and option-adjusted spreads. • Observable market prices of similar securities. Fair value of level 3 securities is determined by: • Internal models, principally discounted cash flow models (income approach). • Revenue multiples of comparable public companies (market approach). For level 3 securities, increases in the discount rate applied in the discounted cash flow models would negatively affect the fair value. Increases in valuation multiples of comparable companies would positively affect the fair value. The valuations provided by the third-party pricing service are based on observable market inputs, which include benchmark yields, reported trades, issuer spreads, benchmark securities, bids, offers, and reference data obtained from market research publications. Inputs used by the third-party pricing service in valuing CMOs and other mortgage-backed securities also include new issue data, monthly payment information, whole loan collateral performance, and “To Be Announced” prices. In valuations of securities issued by state and political subdivisions, inputs used by the third-party pricing service also include material event notices. Level 1, 2, and 3 (primarily Level 2) Commercial loans (trading account assets) Fair value is based on: • Observable market price spreads for similar loans. Valuations reflect prices within the bid-ask spread that are most representative of fair value. Level 2 Principal investments (direct) Direct principal investments consist of equity and debt instruments of private companies made by our principal investing entities. Fair value is determined using: • Operating performance and market multiples of comparable businesses • Other unique facts and circumstances related to each individual investment Direct principal investments are accounted for as investment companies in accordance with the applicable accounting guidance, whereby each investment is adjusted to fair value with any net realized or unrealized gain/loss recorded in the current period’s earnings. We are in the process of winding down our direct principal investment portfolio. As of December 31, 2018, the balance is less than $1 million. Level 3 Principal investments (indirect) Indirect principal investments include primary and secondary investments in private equity funds engaged mainly in venture- and growth-oriented investing. These investments do not have readily determinable fair values and qualify for the practical expedient to estimate fair value based upon net asset value per share (or its equivalent, such as member units or an ownership interest in partners’ capital to which a proportionate share of net assets is attributed). Indirect principal investments are also accounted for as investment companies, whereby each investment is adjusted to fair value with any net realized or unrealized gain/loss recorded in the current period’s earnings. Under the provisions of the Volcker Rule, we are required to dispose or conform our indirect investments to the requirements of the statute by no later than July 21, 2022. As of December 31, 2018, we have not committed to a plan to sell these investments. Therefore, these investments continue to be valued using the net asset value per share methodology. NAV The following table presents the fair value of our direct and indirect principal investments and related unfunded commitments at December 31, 2018 , as well as financial support provided for the years ended December 31, 2018 , and December 31, 2017 . Financial support provided Year ended December 31, December 31, 2018 2018 2017 in millions Fair Value Unfunded Commitments Funded Commitments Funded Other Funded Commitments Funded Other INVESTMENT TYPE Direct investments (a) $ 1 — — — — $ — Indirect investments (b) 96 $ 26 $ 1 — $ 1 — Total $ 97 $ 26 $ 1 — $ 1 $ — (a) Our direct investments consist of equity and debt investments directly in independent business enterprises. Operations of the business enterprises are handled by management of the portfolio company. The purpose of funding these enterprises is to provide financial support for business development and acquisition strategies. We infuse equity capital based on an initial contractual cash contribution and later from additional requests on behalf of the companies’ management. (b) Our indirect investments consist of buyout funds, venture capital funds, and fund of funds. These investments are generally not redeemable. Instead, distributions are received through the liquidation of the underlying investments of the fund. An investment in any one of these funds typically can be sold only with the approval of the fund’s general partners. At December 31, 2018 , no significant liquidation of the underlying investments has been communicated to Key. The purpose of funding our capital commitments to these investments is to allow the funds to make additional follow-on investments and pay fund expenses until the fund dissolves. We, and all other investors in the fund, are obligated to fund the full amount of our respective capital commitments to the fund based on our and their respective ownership percentages, as noted in the applicable Limited Partnership Agreement. Asset/liability class Valuation technique Valuation hierarchy classification(s) Other direct equity investments Fair value is determined using: • Discounted cash flows • Operating performance and market/exit multiples of comparable businesses • Other unique facts and circumstances related to each individual investment For level 3 securities, increases in the discount rate applied in the discounted cash flow models would negatively affect the fair value. Increases in valuation multiples of comparable companies would positively affect the fair value. Level 2 investments reflect the price of recent investments, which is deemed representative of fair value. Level 2 and 3 Other direct and indirect equity investments (NAV) Certain direct investments do not have readily determinable fair values and qualify for the practical expedient in the accounting guidance that allows us to estimate fair value based upon net asset value per share. NAV Loans held for sale and held for investment (residential) Residential mortgage loans held for sale are accounted for at fair value. Fair values are based on: • Quoted market prices, where available • Prices for other traded mortgage loans with similar characteristics • Purchase commitments and bid information received from market participants Prices are adjusted as necessary to include: • The embedded servicing value in the loans • The specific characteristics of certain loans that are priced based on the pricing of similar loans. (These adjustments represent unobservable inputs to the valuation but are not considered significant given the relative insensitivity of the value to changes in these inputs to the fair value of the loans.) Residential loans held for investment: Certain residential loans held for sale contain salability exceptions that make them unable to be sold into the performing loan sales market. Loans in this category are transferred to the held to maturity loan portfolio and are included in “Loans, net of unearned income” on the balance sheet. This type of loan is classified as level 3 in the valuation hierarchy as transaction details regarding sales of this type of loan are often unavailable. Fair value is based upon: • Unobservable bid information from brokers and investors Level 1, 2 and 3 (primarily level 2) Derivatives Exchange-traded derivatives are valued using quoted prices in active markets and, therefore, are classified as Level 1 instruments. The majority of our derivative positions are level 2 and are valued using internally developed models based on market convention and observable market inputs. These derivative contracts include interest rate swaps, certain options, floors, cross currency swaps, credit default swaps, and forward mortgage loan sale commitments. Significant inputs used in the valuation models include: • Interest rate curves • Yield curves • LIBOR and Overnight Index Swap (OIS) discount rates • LIBOR and OIS curves, index pricing curves, foreign currency curves • Volatility surfaces (a three-dimensional graph of implied volatility against strike price and maturity) • Current prices for mortgage securities and investor supplied prices Level 1, 2, and 3 (primarily level 2) Asset/liability class Valuation technique Valuation hierarchy classification(s) Derivatives (continued) We have several customized derivative instruments and risk participations that are classified as Level 3 instruments. These derivative positions are valued using internally developed models, with inputs consisting of available market data, such as: • Bond spreads and asset values The unobservable internally derived assumptions include: • Loss probabilities • Internal risk ratings of customers The fair value represents an estimate of the amount that the risk participation counterparty would need to pay/receive as of the measurement date based on the probability of customer default on the swap transaction and the fair value of the underlying customer swap. Therefore, a higher loss probability and a lower credit rating would negatively affect the fair value of the risk participations and a lower loss probability and higher credit rating would positively affect the fair value of the risk participations. We use interest rate lock commitments for our residential mortgage business, which are classified as Level 3 instruments. The significant components of the valuation model include: • Interest rates observable in the market • Observable market prices for similar securities • The probability of the loan closing (i.e. the "pull-through" amount, a significant unobservable input). Increases in the probability of the loan closing would positively affect the fair value. Valuation of residential mortgage forward sale commitments utilizes observable market prices of comparable commitments and mortgage securities (Level 2). Level 1, 2, and 3 (primarily level 2) Liability for short positions This includes fixed income securities held by our broker dealer in its trading inventory. Fair value of level 1 securities is determined by: • Quoted market prices available in an active market for identical securities Fair value of level 2 securities is determined by: • Observable market prices of similar securities • Market activity, spreads, credit ratings and interest rates for each security type Level 1 and 2 Market convention implies a credit rating of “AA” equivalent in the pricing of derivative contracts, which assumes all counterparties have the same creditworthiness. To reflect the actual exposure on our derivative contracts related to both counterparty and our own creditworthiness, we record a fair value adjustment. The credit component is determined by the individual counterparty based on the probability of default and considers master netting and collateral agreements. We also make liquidity valuation adjustments to the fair value of certain assets to reflect the uncertainty in the pricing and trading of the instruments when we are unable to observe recent market transactions for identical or similar instruments. Liquidity valuation adjustments are based on the following factors: • the amount of time since the last relevant valuation; • whether there is an actual trade or relevant external quote available at the measurement date; and • volatility associated with the primary pricing components. We regularly validate the pricing methodologies of valuations derived from a third-party pricing service to ensure the fair value determination is consistent with the applicable accounting guidance and that our assets are properly classified in the fair value hierarchy. To perform this validation, we: • review documentation received from our third-party pricing service regarding the inputs used in its valuations and determine a level assessment for each category of securities; • substantiate actual inputs used for a sample of securities by comparing the actual inputs used by our third-party pricing service to comparable inputs for similar securities; and • substantiate the fair values determined for a sample of securities by comparing the fair values provided by our third-party pricing service to prices from other independent sources for the same and similar securities. We analyze variances and conduct additional research with our third-party pricing service and take appropriate steps based on our findings. Changes in Level 3 Fair Value Measurements The following table shows the change in the fair values of our Level 3 financial instruments for the years ended December 31, 2018 , and December 31, 2017 . in millions Beginning of Period Balance Gains (Losses) included in comprehensive income Gains (Losses) Included in Earnings Purchases Sales Settlements Transfers Other Transfers into Level 3 (e) Transfers out of Level 3 (e) End of Period Balance Unrealized Gains (Losses) Included in Earnings Year ended December 31, 2018 Securities available for sale Other securities $ 20 — — — — — — — — $ 20 — Other investments Principal investments Direct 13 — $ (1 ) (c) $ 5 $ (16 ) — — — — 1 — (c) Equity investments Direct 3 — — — — — — $ 4 — 7 — Loans held for sale 1 — — — (1 ) — $ (1 ) 1 — — — Loans held for investment 2 — — — — — 1 — — 3 — Derivative instruments (b) Interest rate 9 — (2 ) (d) 1 (2 ) — — 7 (f) $ (8 ) (f) 5 — Credit 1 — (31 ) (d) — — $ 30 — — — — — Other (a) 3 — — — — — — — — 3 — in millions Beginning of Period Balance Gains (Losses) included in comprehensive income Gains (Losses) Included in Earnings Purchases Sales Settlements Transfers Other Transfers into Level 3 (e) Transfers out of Level 3 (e) End of Period Balance Unrealized Gains (Losses) Included in Earnings Year ended December 31, 2017 Securities available for sale Other securities $ 17 $ 3 — — — — — — — $ 20 — Other investments Principal investments Direct 27 — $ (6 ) (c) — $ (8 ) — — — — 13 $ (1 ) (c) Equity investments Direct — — — (c) — — — — $ 3 — 3 — (c) Loans held for sale — — — — (3 ) — $ 4 — — 1 — Loans held for investment — — — — — — 2 — — 2 — Derivative instruments (b) Interest rate 7 — (2 ) (d) $ — — — — 13 (f) $ (9 ) (f) 9 — Credit 1 — (16 ) (d) — — $ 16 — — — 1 — Other (a) 2 — — — — — $ 1 — — 3 — (a) Amounts represent Level 3 interest rate lock commitments. (b) Amounts represent Level 3 derivative assets less Level 3 derivative liabilities. (c) Realized and unrealized gains and losses on principal investments are reported in “other income” on the income statement. Realized and unrealized losses on equity investments are reported in “other income” on the income statement. (d) Realized and unrealized gains and losses on derivative instruments are reported in “corporate services income” and “other income” on the income statement. (e) Our policy is to recognize transfers into and transfers out of Level 3 as of the end of the reporting period. (f) Certain derivatives previously classified as Level 2 were transferred to Level 3 because Level 3 unobservable inputs became significant. Certain derivatives previously classified as Level 3 were transferred to Level 2 because Level 3 unobservable inputs became less significant. Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis Certain assets and liabilities are measured at fair value on a nonrecurring basis in accordance with GAAP. The adjustments to fair value generally result from the application of accounting guidance that requires assets and liabilities to be recorded at the lower of cost or fair value, or assessed for impairment. There were no liabilities measured at fair value on a nonrecurring basis at December 31, 2018 , and December 31, 2017 . The following table presents our assets measured at fair value on a nonrecurring basis at December 31, 2018 , and December 31, 2017 : December 31, 2018 December 31, 2017 in millions Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ASSETS MEASURED ON A NONRECURRING BASIS Impaired loans and leases — — $ 42 $ 42 — — $ 9 $ 9 Accrued income and other assets — — 16 16 — $ 5 133 (a) 138 Total assets on a nonrecurring basis at fair value — — $ 58 $ 58 — $ 5 $ 142 $ 147 (a) At December 31, 2017, we recorded $31 million of impairment related to $119 million of LIHTC and Historic Tax Credit investments impacted by the enactment of the TCJ Act. Refer to the “LIHTC, HTC, and NMTC investments” section below for a description of the valuation technique and inputs applied for this fair value measurement. Qualitative Disclosures of Valuation Techniques The following table describes the valuation techniques and significant inputs used to measure the significant classes of assets and liabilities reported at fair value on a nonrecurring basis, as well as the classification of each within the valuation hierarchy. Asset/liability class Valuation technique Valuation hierarchy classification(s) Impaired loans and leases Loans are evaluated for impairment on a quarterly basis; impairment typically occurs when there is evidence of a probable loss and the expected value of the loan is less than the contractual value of the loan. The amount of the impairment may be determined based on the estimated present value of future cash flows, the fair value of the underlying collateral, or the loan’s observable market price based on recent sales of similar loans and collateral. Cash flow analysis considers internally developed inputs including: • Discount rates • Default rates • Costs of foreclosure • Changes in collateral values The fair value of the underlying collateral, which may take the form of real estate or personal property, is based on internal estimates, field observations, and assessments provided by third-party appraisers. We perform or reaffirm appraisals of collateral-dependent impaired loans at least annually. Appraisals may occur more frequently if the most recent appraisal does not accurately reflect the current market, the debtor is seriously delinquent or chronically past due, or there has been a material deterioration in the performance of the project or condition of the property. Adjustments to outdated appraisals that result in an appraisal value less than the carrying amount of a collateral-dependent impaired loan are reflected in the ALLL. Impaired loans with a specifically allocated allowance based on a cash flow analysis or the value of the underlying collateral are classified as Level 3 assets. Impaired loans with a specifically allocated allowance based on an observable market price that reflects recent sale transactions for similar loans and collateral are classified as Level 2 assets. We adjust the carrying amount of our impaired loans when there is evidence of probable loss and the expected fair value of the loan is less than its contractual amount. Level 2 and 3 Commercial loans held for sale Through a quarterly analysis of our loan portfolios held for sale, which include both performing and nonperforming commercial loans, we determine any adjustments necessary to record the portfolios at the lower of cost or fair value in accordance with GAAP. Valuation inputs include: • Non-binding bids for the respective loans or similar loans • Recent sales transactions • Internal models that emulate recent securitizations Level 2 and 3 Direct financing leases and operating lease assets held for sale Valuations of direct financing leases and operating lease assets held for sale are performed using an internal model that relies on market data, including: • Swap rates and bond ratings • Our own assumptions about the exit market for the leases • Details about the individual leases in the portfolio KEF has master sale and assignment agreements with numerous institutional investors. Historically, multiple quotes are obtained, with the most reasonable formal quotes retained. These nonbinding quotes generally lead to a sale to one of the parties who provided the quote. Leases for which we receive a current nonbinding bid, and for which the sale is considered probable, may be classified as Level 2. The validity of these quotes is supported by historical and continued dealings with institutions that have fulfilled the nonbinding quote in the past. Valuations of lease and operating lease assets held for sale that employ our own assumptions are classified as Level 3 assets. Inputs utilized include changes in the value of leased items and internal credit ratings. In an inactive market, we value assets held for sale through discounted cash flows models that utilize the current buy rate as the discount rate. Buy rates are based on the credit premium inherent in the relevant bond index and the the appropriate swap rate on the measurement date. Level 2 and 3 Asset/liability class Valuation technique Valuation hierarchy classification(s) OREO and other repossessed personal property OREO and other repossessed properties are valued based on: • Appraisals and third-party price opinions, less estimated selling costs Generally, we classify these assets as Level 3, but OREO and other repossessed properties for which we receive binding purchase agreements are classified as Level 2. Returned lease inventory is valued based on market data for similar assets and is classified as Level 2. Assets that are acquired through, or in lieu of, loan foreclosures are recorded initially as held for sale at fair value less estimated selling costs at the date of foreclosure. After foreclosure, valuations are updated periodically, and current market conditions may require the assets to be marked down further to a new cost basis. Level 2 and 3 LIHTC, HTC, and NMTC investments LIHTC, HTC and NMTC operating partnerships are subject to quarterly impairment testing. This evaluation involves measuring the present value of future tax benefits and comparing that value against the current carrying value of the investment. Expected future tax benefit schedules are provided by the partnerships’ general partners on a quarterly basis. These future benefits are discounted to their present value using discounted cash flow modeling that incorporates an appropriate risk premium. LIHTC and HTC investments are impaired when it is more likely than not that the carrying amount of the investment will not be realized. A primary driver of impairment in the fourth quarter of 2017 was the enactment of the TCJ Act, which reduced future depreciation tax benefits expected to be realized by certain LIHTC and HTC investments. Level 3 Other equity investments We have other investments in equity securities that do not have readily determinable fair values and do not qualify for the practical expedient to measure the investment using a net asset value per share. We have elected to measure these securities at cost less impairment plus or minus adjustments due to observable orderly transactions. Impairment is recorded when there is evidence that the expected fair value of the investment has declined to below the recorded cost. At each reporting period, we assess if these investments continue to qualify for this measurement alternative. At December 31, 2018, the carrying amount of equity investments recorded under this method was $107 million. No impairment was recorded for the year ended December 31, 2018. Level 3 Mortgage Servicing Rights Refer to Note 9. Mortgage Servicing Assets Level 3 Quantitative Information about Level 3 Fair Value Measurements The range and weighted-average of the significant unobservable inputs used to fair value our material Level 3 recurring and nonrecurring assets at December 31, 2018 , and December 31, 2017 , along with the valuation techniques used, are shown in the following table: December 31, 2018 Fair Value of Level 3 Assets Valuation Technique Significant Unobservable Input Range (Weighted-Average) Dollars in millions Nonrecurring Impaired loans $ 42 Fair value of underlying collateral Discount 20.00 - 40.00% (21.00%) December 31, 2017 Fair Value of Level 3 Assets Valuation Technique Significant Unobservable Input Range (Weighted-Average) dollars in millions Recurring Other investments — principal investments — direct: $ 13 Individual analysis of the condition of each investment Debt instruments EBITDA multiple N/A (6.00) Equity instruments of private companies EBITDA multiple N/A (6.00) Nonrecurring Impaired loans $ 9 Fair value of underlying collateral Discount 0.00 - 50.00% (23.00%) Fair Value Disclosures of Financial Instruments The levels in the fair value hierarchy ascribed to our financial instruments and the related carrying amounts at December 31, 2018 , and December 31, 2017 , are shown in the following table. December 31, 2018 Fair Value in millions Carrying Amount Level 1 Level 2 Level 3 Measured at NAV Netting Adjustment Total ASSETS (by measurement category) Fair value - net income Trading account assets (b) $ 849 — $ 849 — — — $ 849 Other investments (b) 666 — 1 $ 559 $ 106 — 666 Loans, net of unearned income (residential) (d) 3 — — 3 — — 3 Loans held for sale (residential) (b) 54 — 54 — — — 54 Derivative assets - trading (b) 462 $ 68 736 8 — $ (350 ) (f) 462 Fair value - OCI Securities available for sale (b) 19,428 — 19,408 20 — — 19,428 Derivative assets - hedging (b) (g) 69 2 50 — — 17 (f) 69 Amortized cost Held-to-maturity securities (c) 11,519 — 11,122 — — — 11,122 Loans, net of unearned income (d) 88,666 — — 86,224 — — 86,224 Loans held for sale (b) 1,173 — — 1,173 — — 1,173 Other Cash and short-term investments (a) 3,240 3,240 — — — — 3,240 LIABILITIES (by measurement category) Fair value - net income Derivative liabilities - trading (b) $ 395 $ 58 $ 675 — — $ (338 ) (f) $ 395 Fair value - OCI Derivative liabilities - hedging (b) (g) (9 ) — (10 ) — — 1 (f) (9 ) Amortized cost Time deposits (e) 13,245 — 13,331 — — — 13,331 Short-term borrowings (a) 863 14 849 — — — 863 Long-term debt (e) 13,732 12,576 1,211 — — — 13,787 Other Deposits with no stated maturity (a) 94,064 — 94,064 — — — 94,064 December 31, 2017 Fair Value in millions Carrying Amount Level 1 Level 2 Level 3 Measured at NAV Netting Adjustment Total ASSETS (by measurement category) Fair value - net income Trading account assets (b) $ 836 — $ 836 — — — $ 836 Other investments (b) 726 — 4 $ 598 $ 124 — 726 Loans, net of unearned income (residential) (d) 2 — — 2 — — 2 Loans held for sale (residential) (b) 71 — 70 1 — — 71 Derivative assets - trading (b) 681 $ 99 918 13 — $ (349 ) (f) 681 Fair value - OCI Securities available for sale (b) 18,139 — 18,119 20 — — 18,139 Derivative assets - hedging (b) (g) (12 ) 1 81 — — (94 ) (f) (12 ) Amortized cost Held-to-maturity securities (c) 11,830 — 11,565 — — — 11,565 Loans, net of unearned income (d) 85,526 — — 84,003 — — 84,003 Loans held for sale (b) 1,036 — — 1,036 — — 1,036 Other Cash and short-term investments (a) 5,118 5,118 — — — — 5,118 LIABILITIES (by measurement category) Fair value - net income Derivative liabilities - trading (b) $ 289 $ 94 $ 763 — — $ (568 ) (f) $ 289 Fair value - OCI Derivative liabilities - hedging (b) (g) 2 4 46 — — (48 ) (f) 2 Amortized cost Time deposits (e) 11,647 — 11,750 — — — 11,750 Short-term borrowings (a) 1,011 72 939 — — — 1,011 Long-term debt (e) 14,333 13,407 $ 1,219 — — — 14,626 Other Deposits with no stated maturity (a) 93,588 — 93,588 — — — 93,588 Valuation Methods and Assumptions (a) Fair value equals or approximates carrying amount. The fair value of deposits with no stated maturity does not take into consideration the value ascribed to core deposit intangibles. (b) Information pertaining to our methodology for measuring the fair values of these assets and

Securities

Securities	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Securities	7. Securities The amortized cost, unrealized gains and losses, and approximate fair value of our securities available for sale and held-to-maturity securities are presented in the following tables. Gross unrealized gains and losses represent the difference between the amortized cost and the fair value of securities on the balance sheet as of the dates indicated. Accordingly, the amount of these gains and losses may change in the future as market conditions change. 2018 2017 December 31, in millions Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value SECURITIES AVAILABLE FOR SALE U.S. Treasury, Agencies, and Corporations $ 150 — $ 3 $ 147 $ 159 — $ 2 $ 157 States and political subdivisions 7 — — 7 9 — — 9 Agency residential collateralized mortgage obligations 14,315 $ 20 373 13,962 14,985 $ 10 335 14,660 Agency residential mortgage-backed securities 2,128 13 36 2,105 1,456 3 20 1,439 Agency commercial mortgage-backed securities 3,300 19 132 3,187 1,920 — 66 1,854 Other securities 17 3 — 20 17 3 — 20 Total securities available for sale $ 19,917 $ 55 $ 544 $ 19,428 $ 18,546 $ 16 $ 423 $ 18,139 HELD-TO-MATURITY SECURITIES Agency residential collateralized mortgage obligations $ 7,021 2 $ 254 $ 6,769 $ 8,055 — $ 224 $ 7,831 Agency residential mortgage-backed securities 490 $ — 14 476 574 $ 1 4 571 Agency commercial mortgage-backed securities 3,996 2 133 3,865 3,186 6 44 3,148 Other securities 12 — — 12 15 — — 15 Total held-to-maturity securities $ 11,519 $ 4 $ 401 $ 11,122 $ 11,830 $ 7 $ 272 $ 11,565 The following table summarizes our securities that were in an unrealized loss position as of December 31, 2018 , and December 31, 2017 : Duration of Unrealized Loss Position Less than 12 Months 12 Months or Longer Total in millions Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses December 31, 2018 Securities available for sale: U.S. Treasury, Agencies, and Corporations — — $ 147 $ 3 $ 147 $ 3 Agency residential collateralized mortgage obligations $ 570 $ 2 10,945 371 11,515 373 Agency residential mortgage-backed securities 4 — (a) 1,087 36 1,091 36 Agency commercial mortgage-backed securities — — 1,729 132 1,729 132 Held-to-maturity securities: Agency residential collateralized mortgage obligations — — 6,416 254 6,416 254 Agency residential mortgage-backed securities — — 475 14 475 14 Agency commercial mortgage-backed securities 73 — (a) 3,359 133 3,432 133 Other securities — — — — — — Total temporarily impaired securities $ 647 $ 2 $ 24,158 $ 943 $ 24,805 $ 945 December 31, 2017 Securities available for sale: U.S. Treasury, Agencies, and Corporations $ 41 — (b) 116 $ 2 $ 157 $ 2 Agency residential collateralized mortgage obligations 6,153 $ 74 $ 7,270 261 13,423 335 Agency residential mortgage-backed securities 666 7 702 13 1,368 20 Agency commercial mortgage-backed securities 205 4 1,649 62 1,854 66 Held-to-maturity securities: Agency residential collateralized mortgage obligations 2,201 27 5,599 197 7,800 224 Agency residential mortgage-backed securities 252 1 206 3 458 4 Agency commercial mortgage-backed securities 1,470 12 495 32 1,965 44 Other securities 3 — (b) 4 — (b) 7 — Total temporarily impaired securities $ 10,991 $ 125 $ 16,041 $ 570 $ 27,032 $ 695 (a) At December 31, 2018 , gross unrealized losses totaled less than $1 million for agency residential mortgage-backed securities available for sale with a loss duration of less than 12 months and less than $1 million for agency commercial mortgage-backed securities held-to-maturity with a loss duration of less than 12 months. (b) At December 31, 2017 , gross unrealized losses totaled less than $1 million for U.S. Treasury, Agencies, and Corporations available for sale with a loss duration of less than 12 months and less than $1 million for other securities held-to-maturity with a loss duration of less than and greater than 12 months. At December 31, 2018 , we had $373 million of gross unrealized losses related to 450 fixed-rate agency residential CMOs that we invested in as part of our overall A/LM strategy. These securities had a weighted-average maturity of 4.83 years years at December 31, 2018 . At December 31, 2018 , we also had $36 million of gross unrealized losses related to 252 agency residential mortgage-backed securities positions and $132 million of gross unrealized losses related to 14 agency commercial mortgage-backed securities positions with weighted-average maturities of 3.87 years and 4.12 years, respectively, at December 31, 2018 . Because these securities have a fixed interest rate, their fair value is sensitive to movements in market interest rates. These unrealized losses are considered temporary since we expect to collect all contractually due amounts from these securities. Accordingly, these investments were reduced to their fair value through OCI, not earnings. We regularly assess our securities portfolio for OTTI. The assessments are based on the nature of the securities, the underlying collateral, the financial condition of the issuer, the extent and duration of the loss, our intent related to the individual securities, and the likelihood that we will have to sell securities prior to expected recovery. We did no t have any impairment losses recognized in earnings for the year ended December 31, 2018 . Realized gains and losses related to securities available for sale were as follows: Year ended December 31, in millions 2018 (a) 2017 (b) 2016 (a) Realized gains — $ 1 — Realized losses — — — Net securities gains (losses) — $ 1 — (a) Realized losses totaled less than $1 million for the year ended December 31, 2018 , and December 31, 2016 . (b) Realized losses totaled less than $1 million for the year ended December 31, 2017 . At December 31, 2018 , securities available-for-sale and held-to-maturity securities totaling $9.0 billion were pledged to secure securities sold under repurchase agreements, to secure public and trust deposits, to facilitate access to secured funding, and for other purposes required or permitted by law. The following table shows securities by remaining maturity. CMOs and other mortgage-backed securities in the available-for-sale and held-to-maturity portfolios are presented based on their expected average lives. The remaining securities, in both the available-for-sale and held-to-maturity portfolios, are presented based on their remaining contractual maturity. Actual maturities may differ from expected or contractual maturities since borrowers have the right to prepay obligations with or without prepayment penalties. Securities Available for Sale Held-to-Maturity Securities December 31, 2018 Amortized Cost Fair Value Amortized Cost Fair Value in millions Due in one year or less $ 116 $ 116 $ 36 $ 36 Due after one through five years 12,298 11,949 6,402 6,210 Due after five through ten years 7,492 7,352 5,081 4,876 Due after ten years 11 11 — — Total $ 19,917 $ 19,428 $ 11,519 $ 11,122

Derivatives and Hedging Activit

Derivatives and Hedging Activities	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	8. Derivatives and Hedging Activities We are a party to various derivative instruments, mainly through our subsidiary, KeyBank. The primary derivatives that we use are interest rate swaps, caps, floors, forwards and futures; foreign exchange contracts; commodity derivatives; and credit derivatives. These instruments help us manage exposure to interest rate risk, mitigate the credit risk inherent in our loan portfolio, hedge against changes in foreign currency exchange rates, and meet client financing and hedging needs. As further discussed in this note: • interest rate risk is the risk that the EVE or net interest income will be adversely affected by fluctuations in interest rates; • credit risk is the risk of loss arising from an obligor’s inability or failure to meet contractual payment or performance terms; and • foreign exchange risk is the risk that an exchange rate will adversely affect the fair value of a financial instrument. At December 31, 2018 , after taking into account the effects of bilateral collateral and master netting agreements, we had $69 million of derivative assets and a positive $9 million of derivative liabilities that relate to contracts entered into for hedging purposes. As of the same date, after taking into account the effects of bilateral collateral and master netting agreements and a reserve for potential future losses, we had derivative assets of $462 million and derivative liabilities of $395 million that were not designated as hedging instruments. These positions are primarily comprised of derivative contracts entered into for client accommodation purposes. Additional information regarding our accounting policies for derivatives is provided in Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Derivatives and Hedging.” Derivatives Designated in Hedge Relationships Net interest income and the EVE change in response to changes in the mix of assets, liabilities, and off-balance sheet instruments and the associated interest rates tied to each instrument. In addition, differences in the repricing and maturity characteristics of interest-earning assets and interest-bearing liabilities cause net interest income and the EVE to fluctuate. We utilize derivatives that have been designated as part of a hedge relationship in accordance with the applicable accounting guidance to manage net interest income and EVE to within our stated risk tolerances. The primary derivative instruments used to manage interest rate risk are interest rate swaps. We designate certain “receive fixed/pay variable” interest rate swaps as fair value hedges. These contracts convert certain fixed-rate long-term debt into variable-rate obligations, thereby modifying our exposure to changes in interest rates. As a result, we receive fixed-rate interest payments in exchange for making variable-rate payments over the lives of the contracts without exchanging the notional amounts. Similarly, we designate certain “receive fixed/pay variable” interest rate swaps as cash flow hedges. These contracts effectively convert certain floating-rate loans into fixed-rate loans to reduce the potential adverse effect of interest rate decreases on future interest income. Again, we receive fixed-rate interest payments in exchange for making variable-rate payments over the lives of the contracts without exchanging the notional amounts. We designate interest rate floors as cash flow hedges. Interest rate floors also reduce the potential adverse effect of interest rate decreases on future interest income. We receive interest payments when the strike price specified in the contracts falls below a reference rate in exchange for an upfront premium. We designate certain “pay fixed/receive variable” interest rate swaps as cash flow hedges. These swaps convert certain floating-rate debt into fixed-rate debt. We also use these swaps to manage the interest rate risk associated with anticipated sales of certain commercial real estate loans. The swaps protect against the possible short-term decline in the value of the loans that could result from changes in interest rates between the time they are originated and the time they are sold. We use foreign currency forward transactions to hedge the foreign currency exposure of our net investment in various foreign equipment finance entities. These entities are denominated in a non-U.S. currency. These swaps are designated as net investment hedges to mitigate the exposure of measuring the net investment at the spot foreign exchange rate. Derivatives Not Designated in Hedge Relationships We may enter into interest rate swap contracts to manage economic risks but do not designate the instruments in hedge relationships. Excluding contracts addressing customer exposures, the amount of derivatives hedging risks on an economic basis at December 31, 2018 , was not significant. Like other financial services institutions, we originate loans and extend credit, both of which expose us to credit risk. We actively manage our overall loan portfolio and the associated credit risk in a manner consistent with asset quality objectives and concentration risk tolerances to mitigate portfolio credit risk. Purchasing credit protection through default swaps enables us to transfer to a third party a portion of the credit risk associated with a particular extension of credit, including situations where there is a forecasted sale of loans. We purchase credit default swaps to reduce the credit risk associated with the debt securities held in our trading portfolio. We also enter into derivative contracts for other purposes, including: • interest rate swap, cap, and floor contracts entered into generally to accommodate the needs of commercial loan clients; • energy and base metal swap and option contracts entered into to accommodate the needs of clients; • foreign exchange forward and option contracts entered into primarily to accommodate the needs of clients; and • futures contracts and positions with third parties that are intended to offset or mitigate the interest rate or market risk related to client positions discussed above. Fair Values, Volume of Activity, and Gain/Loss Information Related to Derivative Instruments The following table summarizes the fair values of our derivative instruments on a gross and net basis as of December 31, 2018 , and December 31, 2017 . The change in the notional amounts of these derivatives by type from December 31, 2017 , to December 31, 2018 , indicates the volume of our derivative transaction activity during 2018 . The notional amounts are not affected by bilateral collateral and master netting agreements. The derivative asset and liability balances are presented on a gross basis, prior to the application of bilateral collateral and master netting agreements. Total derivative assets and liabilities are adjusted to take into account the impact of legally enforceable master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Where master netting agreements are not in effect or are not enforceable under bankruptcy laws, we do not adjust those derivative assets and liabilities with counterparties. Securities collateral related to legally enforceable master netting agreements is not offset on the balance sheet. Our derivative instruments are included in “accrued income and other assets” or “accrued expenses and other liabilities” on the balance sheet, as indicated in the following table: December 31, 2018 December 31, 2017 Fair Value Fair Value in millions Notional Amount Derivative Assets Derivative Liabilities Notional Amount Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments: Interest rate $ 28,546 $ 50 $ (10 ) $ 26,176 $ 81 $ 46 Foreign exchange 122 2 — 302 1 4 Total 28,668 52 (10 ) 26,478 82 50 Derivatives not designated as hedging instruments: Interest rate 63,454 365 307 61,390 641 474 Foreign exchange 6,829 104 95 8,317 129 120 Commodity 2,002 333 323 1,687 255 246 Credit 226 1 1 315 1 4 Other (a) 1,466 9 7 2,006 4 13 Total 73,977 812 733 73,715 1,030 857 Netting adjustments (b) — (333 ) (337 ) — (443 ) (616 ) Net derivatives in the balance sheet 102,645 531 386 100,193 669 291 Other collateral (c) — (2 ) (33 ) — (5 ) (84 ) Net derivative amounts $ 102,645 $ 529 $ 353 $ 100,193 $ 664 $ 207 (a) Other derivatives include interest rate lock commitments and forward sale commitments related to our residential mortgage banking activities, forward purchase and sales contracts consisting of contractual commitments associated with “to be announced” securities and when issued securities, and when-issued security transactions in connection with an “at-the-market” equity offering program. (b) Netting adjustments represent the amounts recorded to convert our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. (c) Other collateral represents the amount that cannot be used to offset our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. The other collateral consists of securities and is exchanged under bilateral collateral and master netting agreements that allow us to offset the net derivative position with the related collateral. The application of the other collateral cannot reduce the net derivative position below zero. Therefore, excess other collateral, if any, is not reflected above. Fair value hedges. During the year ended December 31, 2018 , we did not exclude any portion of these hedging instruments from the assessment of hedge effectiveness. The following table summarizes the amounts that were recorded on the balance sheet as of December 31, 2018 , related to cumulative basis adjustments for fair value hedges. December 31, 2018 in millions Balance sheet line item in which the hedge item is included Carrying amount of hedged item (a) Hedge accounting basis adjustment (b) Interest rate contracts Long-term debt $ 9,363 $ (6 ) Interest rate contracts Certificate of deposit ($100,000 or more) 343 (1 ) Interest rate contracts Other time deposits 178 — (a) The carrying amount represents the portion of the liability designated as the hedged item. (b) Basis adjustment includes $10 million related to de-designated hedged items no longer in qualifying fair value hedging relationships. Cash flow hedges. During the year ended December 31, 2018 , we did not exclude any portion of these hedging instruments from the assessment of hedge effectiveness. Considering the interest rates, yield curves, and notional amounts as of December 31, 2018 , we would expect to reclassify an estimated $38 million of after-tax net gains on derivative instruments from AOCI to income during the next 12 months for our cash flow hedges. In addition, we expect to reclassify approximately $31 million of net losses related to terminated cash flow hedges from AOCI to income during the next 12 months . As of December 31, 2018 , the maximum length of time over which we hedge forecasted transactions is 10 years . The following tables summarize the effect of fair value and cash flow hedge accounting on the income statement for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 . Location and amount of net gains (losses) recognized in income on fair value and cash flow hedging relationships (a) in millions Interest expense – long-term debt Interest income – loans Investment banking and debt placement fees Interest expense – deposits Other income Year ended December 31, 2018 Total amounts presented in the consolidated statement of income $ (420 ) $ 4,023 $ 650 $ (517 ) $ 176 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items (5 ) — — 1 — Recognized on derivatives designated as hedging instruments (12 ) — — — — Net income (expense) recognized on fair value hedges (17 ) — — 1 — Net gain (loss) on cash flow hedging relationships Interest contracts Realized gains (losses) (pre-tax) reclassified from AOCI into net income (2 ) (68 ) 2 — 31 Net income (expense) recognized on cash flow hedges $ (2 ) $ (68 ) $ 2 — 31 Year ended December 31, 2017 Total amounts presented in the consolidated statement of income $ (319 ) $ 3,677 $ 603 $ (278 ) $ 153 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items — — — — 107 Recognized on derivatives designated as hedging instruments 49 — — — (103 ) Net income (expense) recognized on fair value hedges $ 49 — — — $ 4 Net gain (loss) on cash flow hedging relationships Interest contracts Realized gains (losses) (pre-tax) reclassified from AOCI into net income $ (4 ) $ 19 — — — Gains (losses) (before tax) recognized in income for hedge ineffectiveness — — — — — Net income (expense) recognized on cash flow hedges $ (4 ) $ 19 $ — — — Year ended December 31, 2016 Total amounts presented in the consolidated statement of income $ (218 ) $ 2,773 $ 482 $ (171 ) $ 114 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items — — — — 97 Recognized on derivatives designated as hedging instruments 96 — — — (95 ) Net income (expense) recognized on fair value hedges 96 — — — 2 Net gain (loss) on cash flow hedging relationships Interest contracts Realized gains (losses) (pre-tax) reclassified from AOCI into net income (4 ) 85 — — — Gains (losses) (before tax) recognized in income for hedge ineffectiveness — — — — — Net income (expense) recognized on cash flow hedges $ (4 ) $ 85 $ — — — (a) Prior period gain or loss amounts were not restated to conform to the new hedge accounting guidance adopted in 2018. Net investment hedges. We enter into foreign currency forward contracts to hedge our exposure to changes in the carrying value of our investments as a result of changes in the related foreign exchange rates. At December 31, 2018 , AOCI reflected unrecognized after-tax gains totaling $27 million related to cumulative changes in the fair value of our net investment hedges, which offset the unrecognized after-tax foreign currency losses on net investment balances. We did not exclude any portion of our hedging instruments from the assessment of hedge effectiveness during the year ended December 31, 2018 . The following table summarizes the pre-tax net gains (losses) on our cash flow and net investment hedges for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 , and where they are recorded on the income statement. The table includes net gains (losses) recognized in OCI during the period and net gains (losses) reclassified from OCI into income during the current period. in millions Net Gains (Losses) Recognized in OCI Income Statement Location of Net Gains (Losses) Reclassified From OCI Into Income Net Gains (Losses) Reclassified From OCI Into Income (a) Net Gains (Losses) Recognized in Other Income (a) Year ended December 31, 2018 Cash Flow Hedges Interest rate $ (13 ) Interest income — Loans $ (68 ) $ — Interest rate 2 Interest expense — Long-term debt (2 ) — Interest rate 1 Investment banking and debt placement fees 2 — Net Investment Hedges Foreign exchange contracts 19 Other Income 31 — Total $ 9 $ (37 ) $ — Year ended December 31, 2017 Cash Flow Hedges Interest rate $ (59 ) Interest income — Loans $ 19 $ — Interest rate — Interest expense — Long-term debt (4 ) — Interest rate (1 ) Investment banking and debt placement fees — — Net Investment Hedges Foreign exchange contracts (17 ) Other Income — — Total $ (77 ) $ 15 $ — Year ended December 31, 2016 Cash Flow Hedges Interest rate $ 29 Interest income — Loans $ 85 $ — Interest rate — Interest expense — Long-term debt (4 ) — Interest rate 1 Investment banking and debt placement fees — — Net Investment Hedges Foreign exchange contracts (2 ) Other Income — — Total $ 28 $ 81 $ — (a) Prior period gain or loss amounts were not restated to conform to the new hedge accounting guidance adopted in 2018. Nonhedging instruments. The following table summarizes the pre-tax net gains (losses) on our derivatives that are not designated as hedging instruments for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 , and where they are recorded on the income statement. 2018 2017 2016 Year ended December 31, in millions Corporate Services Income Consumer Mortgage Income Other Income Total Corporate Services Income Consumer Mortgage Income Other Income Total Corporate Services Income Consumer Mortgage Income Other Income Total NET GAINS (LOSSES) Interest rate $ 38 — $ (1 ) $ 37 $ 29 — $ (1 ) $ 28 $ 30 — $ 1 $ 31 Foreign exchange 42 — — 42 41 — — 41 40 — — 40 Commodity 8 — — 8 6 — — 6 4 — — 4 Credit 2 — (30 ) (28 ) 2 — (21 ) (19 ) 1 — (16 ) (15 ) Other — $ (1 ) 12 11 — $ (1 ) (6 ) (7 ) — $ 1 — 1 Total net gains (losses) $ 90 $ (1 ) $ (19 ) $ 70 $ 78 $ (1 ) $ (28 ) $ 49 $ 75 $ 1 $ (15 ) $ 61 Counterparty Credit Risk We use several means to mitigate and manage exposure to credit risk on derivative contracts. We enter into bilateral collateral and master netting agreements that provide for the net settlement of all contracts with a single counterparty in the event of default. Additionally, we monitor counterparty credit risk exposure on each contract to determine appropriate limits on our total credit exposure across all product types. We review our collateral positions on a daily basis and exchange collateral with our counterparties in accordance with standard ISDA documentation, central clearing rules, and other related agreements. We hold collateral in the form of cash and highly rated securities issued by the U.S. Treasury, government-sponsored enterprises, or GNMA. Cash collateral netted against derivative assets on the balance sheet totaled $33 million at December 31, 2018 , and $23 million at December 31, 2017 . The cash collateral netted against derivative liabilities totaled $37 million at December 31, 2018 , and $150 million at December 31, 2017 . The following table summarizes the fair value of our derivative assets by type at the dates indicated. These assets represent our gross exposure to potential loss after taking into account the effects of bilateral collateral and master netting agreements and other means used to mitigate risk. December 31, in millions 2018 2017 Interest rate $ 308 $ 401 Foreign exchange 60 77 Commodity 187 163 Credit — 1 Other 9 4 Derivative assets before collateral 564 646 Less: Related collateral 33 (23 ) Total derivative assets $ 531 $ 669 We enter into derivative transactions with two primary groups: broker-dealers and banks, and clients. Since these groups have different economic characteristics, we have different methods for managing counterparty credit exposure and credit risk. We enter into transactions with broker-dealers and banks for various risk management purposes. These types of transactions are primarily high dollar volume. We enter into bilateral collateral and master netting agreements with these counterparties. We clear certain types of derivative transactions with these counterparties, whereby central clearing organizations become the counterparties to our derivative contracts. In addition, we enter into derivative contracts through swap execution facilities. Swap clearing and swap execution facilities reduce our exposure to counterparty credit risk. At December 31, 2018 , we had gross exposure of $382 million to broker-dealers and banks. We had net exposure of $241 million after the application of master netting agreements and cash collateral, where such qualifying agreements exist. We had net exposure of $237 million after considering $4 million of additional collateral held in the form of securities. We enter into transactions with clients to accommodate their business needs. These types of transactions generally are primarily low dollar volume. We enter into master netting agreements with these counterparties. In addition, we mitigate our overall portfolio exposure and market risk by buying and selling U.S. Treasuries and Eurodollar futures and entering into offsetting positions and other derivative contracts, sometimes with entities other than broker-dealers and banks. Due to the smaller size and magnitude of the individual contracts with clients, we typically do not exchange collateral in connection with these derivative transactions. To address the risk of default associated with the uncollateralized contracts, we have established a credit valuation adjustment (included in “accrued income and other assets”) in the amount of $4 million at December 31, 2018 , which we estimate to be the potential future losses on amounts due from client counterparties in the event of default. At December 31, 2018 , we had gross exposure of $345 million to client counterparties and other entities that are not broker-dealers or banks for derivatives that have associated master netting agreements. We had net exposure of $290 million on our derivatives with these counterparties after the application of master netting agreements, collateral, and the related reserve. Credit Derivatives We are a buyer and, under limited circumstances, may be a seller of credit protection through the credit derivative market. We purchase credit derivatives to manage the credit risk associated with specific commercial lending and swap obligations as well as exposures to debt securities. Our credit derivative portfolio was in a net liability position of less than $1 million as of December 31, 2018 and $3 million as of December 31, 2017 . Our credit derivative portfolio consists of the following: • Single-name credit default swap : A bilateral contract whereby the seller agrees, for a premium, to provide protection against the credit risk of a specific entity (the “reference entity”) in connection with a specific debt obligation. The protected credit risk is related to adverse credit events, such as bankruptcy, failure to make payments, and acceleration or restructuring of obligations, identified in the credit derivative contract. • Traded credit default swap index: Represents a position on a basket or portfolio of reference entities. • Risk participation agreement: A transaction in which the lead participant has a swap agreement with a customer. The lead participant (purchaser of protection) then enters into a risk participation agreement with a counterparty (seller of protection), under which the counterparty receives a fee to accept a portion of the lead participant’s credit risk. If the customer defaults on the swap contract, the counterparty to the risk participation agreement must reimburse the lead participant for the counterparty’s percentage of the positive fair value of the customer swap as of the default date. If the customer swap has a negative fair value, the counterparty has no reimbursement requirements. If the customer defaults on the swap contract and the seller fulfills its payment obligations under the risk participation agreement, the seller is entitled to a pro rata share of the lead participant’s claims against the customer under the terms of the swap agreement. The following table provides information on the types of credit derivatives sold by us and held on the balance sheet at December 31, 2018 , and December 31, 2017 . The notional amount represents the maximum amount that the seller could be required to pay. The payment/performance risk assessment is based on the default probabilities for the underlying reference entities’ debt obligations using a Moody’s credit ratings matrix known as Moody’s “Idealized” Cumulative Default Rates. The payment/performance risk shown in the table represents a weighted-average of the default probabilities for all reference entities in the respective portfolios. These default probabilities are directly correlated to the probability that we will have to make a payment under the credit derivative contracts. 2018 2017 December 31, dollars in millions Notional Amount Average Term (Years) Payment / Performance Risk Notional Amount Average Term (Years) Payment / Performance Risk Other $ 22 13.43 17.18 % $ 15 3.08 6.64 % Total credit derivatives sold $ 22 — — $ 15 — — Credit Risk Contingent Features We have entered into certain derivative contracts that require us to post collateral to the counterparties when these contracts are in a net liability position. The amount of collateral to be posted is based on the amount of the net liability and thresholds generally related to our long-term senior unsecured credit ratings with Moody’s and S&P. Collateral requirements also are based on minimum transfer amounts, which are specific to each Credit Support Annex (a component of the ISDA Master Agreement) that we have signed with the counterparties. In a limited number of instances, counterparties have the right to terminate their ISDA Master Agreements with us if our ratings fall below a certain level, usually investment-grade level (i.e., “Baa3” for Moody’s and “BBB-” for S&P). At December 31, 2018 , KeyBank’s rating was “ A3 ” with Moody’s and “ A- ” with S&P, and KeyCorp’s rating was “ Baa1 ” with Moody’s and “ BBB+ ” with S&P. As of December 31, 2018 , the aggregate fair value of all derivative contracts with credit risk contingent features (i.e., those containing collateral posting or termination provisions based on our ratings) held by KeyBank that were in a net liability position totaled $66 million , which includes $80 million in derivative assets and $146 million in derivative liabilities. We had $55 million in cash and securities collateral posted to cover those positions as of December 31, 2018 . There were no derivative contracts with credit risk contingent features held by KeyCorp at December 31, 2018 . The following table summarizes the additional cash and securities collateral that KeyBank would have been required to deliver under the ISDA Master Agreements had the credit risk contingent features been triggered for the derivative contracts in a net liability position as of December 31, 2018 , and December 31, 2017 . The additional collateral amounts were calculated based on scenarios under which KeyBank’s ratings are downgraded one, two, or three ratings as of December 31, 2018 , and December 31, 2017 , and take into account all collateral already posted. A similar calculation was performed for KeyCorp, and no additional collateral would have been required at December 31, 2018 , or December 31, 2017 . December 31, in millions 2018 2017 Moody’s S&P Moody’s S&P KeyBank’s long-term senior unsecured credit ratings A3 A- A3 A- One rating downgrade $ 2 $ 2 $ 2 $ 2 Two rating downgrades 2 2 2 2 Three rating downgrades 2 2 2 2 KeyBank’s long-term senior unsecured credit rating was four ratings above noninvestment grade at Moody’s and S&P as of December 31, 2018 , and December 31, 2017 . If KeyBank’s ratings had been downgraded below investment grade as of December 31, 2018 , and December 31, 2017 , payments of up to $4 million and $12 million , respectively, would have been required to either terminate the contracts or post additional collateral for those contracts in a net liability position, taking into account all collateral already posted. If KeyCorp’s ratings had been downgraded below investment grade as of December 31, 2018 , and December 31, 2017 , no payments would have

Mortgage Servicing Assets

Mortgage Servicing Assets	12 Months Ended
	Dec. 31, 2018
Servicing Asset [Abstract]
Mortgage Servicing Assets	9. Mortgage Servicing Assets We originate and periodically sell commercial and residential mortgage loans but continue to service those loans for the buyers. We also may purchase the right to service commercial mortgage loans for other lenders. We record a servicing asset if we purchase or retain the right to service loans in exchange for servicing fees that exceed the going market servicing rate and are considered more than adequate compensation for servicing. Additional information pertaining to the accounting for mortgage and other servicing assets is included in Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Servicing Assets.” Commercial Changes in the carrying amount of commercial mortgage servicing assets are summarized as follows: Year ended December 31, in millions 2018 2017 Balance at beginning of period $ 412 $ 356 Servicing retained from loan sales 117 110 Purchases 75 36 Amortization (102 ) (90 ) Balance at end of period $ 502 $ 412 Fair value at end of period $ 757 $ 537 The fair value of commercial mortgage servicing assets is determined by calculating the present value of future cash flows associated with servicing the commercial mortgage loans. This calculation uses a number of assumptions that are based on current market conditions. The range and weighted-average of the significant unobservable inputs used to fair value our commercial mortgage servicing assets at December 31, 2018 , and December 31, 2017 , along with the valuation techniques, are shown in the following table: dollars in millions December 31, 2018 December 31, 2017 Valuation Technique Significant Unobservable Input Range (Weighted-Average) Discounted cash flow Expected defaults 1.00 - 2.00% (1.14%) 1.00 - 3.00% (1.20%) Residual cash flows discount rate 7.00 - 15.00% (9.18%) 7.00 - 15.00% (9.10%) Escrow earn rate 2.56 - 4.20% (3.35%) .90 - 3.10% (2.50%) Loan assumption rate 0.00 - 3.22% (1.35%) 0.00 - 3.00% (1.22%) If these economic assumptions change or prove incorrect, the fair value of commercial mortgage servicing assets may also change. Expected credit losses, escrow earn rates, and discount rates are critical to the valuation of commercial mortgage servicing assets. Estimates of these assumptions are based on how a market participant would view the respective rates and reflect historical data associated with the commercial mortgage loans, industry trends, and other considerations. Actual rates may differ from those estimated due to changes in a variety of economic factors. A decrease in the value assigned to the escrow earn rates would cause a decrease in the fair value of our commercial mortgage servicing assets. An increase in the assumed default rates of commercial mortgage loans or an increase in the assigned discount rates would cause a decrease in the fair value of our commercial mortgage servicing assets. Prepayment activity on commercial serviced loans does not significantly impact the valuation of our commercial mortgage servicing assets. Unlike residential mortgages, commercial mortgages experience significantly lower prepayments due to certain contractual restrictions impacting the borrower’s ability to prepay the mortgage. The amortization of commercial mortgage servicing assets for each period, as shown in the table at the beginning of this note, is recorded as a reduction to contractual fee income. The contractual fee income from servicing commercial mortgage loans totaled $171 million for the year ended December 31, 2018 , $150 million for the year ended December 31, 2017 , and $139 million for the year ended December 31, 2016 . This fee income was partially offset by $102 million of amortization for the year ended December 31, 2018 , $90 million for the year ended December 31, 2017 , and $87 million for the year ended December 31, 2016 . Both the contractual fee income and the amortization are recorded, net, in “mortgage servicing fees” on the income statement. Residential Changes in the carrying amount of residential mortgage servicing assets are summarized as follows: in millions 2018 2017 Balance at beginning of period $ 31 28 Servicing retained from loan sales 10 $ 7 Purchases — — Amortization (4 ) (4 ) Balance at end of period $ 37 $ 31 Fair value at end of period $ 52 $ 37 The fair value of residential mortgage servicing assets is determined by calculating the present value of future cash flows associated with servicing the residential mortgage loans. This calculation uses a number of assumptions that are based on current market conditions. The range and weighted-average of the significant unobservable inputs used to fair value our residential mortgage servicing assets at December 31, 2018 , along with the valuation techniques, are shown in the following table: December 31, 2018 December 31, 2017 Valuation Technique Significant Unobservable Input Range (Weighted-Average) Discounted cash flow Prepayment speed 8.45 - 56.11% (9.08%) 9.16 - 51.52% (10.46%) Discount rate 7.50 - 10.00% (7.54%) 8.50 - 11.00% (8.54%) Servicing cost $62 - $5,125 ($68.25) $76 - $4,385 ($83.11) If these economic assumptions change or prove incorrect, the fair value of residential mortgage servicing assets may also change. Prepayment speed, discount rates, and servicing cost are critical to the valuation of residential mortgage servicing assets. Estimates of these assumptions are based on how a market participant would view the respective rates and reflect historical data associated with the residential mortgage loans, industry trends, and other considerations. Actual rates may differ from those estimated due to changes in a variety of economic factors. An increase in the prepayment speed would cause a negative impact on the fair value of our residential mortgage servicing assets. An increase in the assigned discount rates and servicing cost assumptions would cause a decrease in the fair value of our residential mortgage servicing assets. The amortization of residential mortgage servicing assets for December 31, 2018 , as shown in the table above, is recorded as a reduction to contractual fee income. The contractual fee income from servicing residential mortgage loans totaled $14 million for the year ended December 31, 2018 . This fee income was offset by $4 million of amortization for the year ended December 31, 2018

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Premises and Equipment	10. Premises and Equipment Premises and equipment at December 31, 2018 , and December 31, 2017 , consisted of the following: December 31, dollars in millions Useful life (in years) 2018 2017 Land Indefinite $ 135 $ 138 Buildings and improvements 15-40 747 741 Leasehold improvements 1-15 626 633 Furniture and equipment 2-15 907 931 Capitalized building leases 1-14 (a) 28 27 Construction in process N/A 35 38 Total premises and equipment 2,478 2,508 Less: Accumulated depreciation and amortization (1,596 ) (1,578 ) Premises and equipment, net $ 882 $ 930 (a) Capitalized building and equipment leases are amortized over the lesser of the useful life of asset or lease term. Depreciation and amortization expense related to premises and equipment for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 was $129 million , $138 million , and $123 million

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	11. Goodwill and Other Intangible Assets Our annual goodwill impairment testing is performed as of October 1 each year, or more frequently as events occur or circumstances change that would more-likely-than-not reduce the fair value of a reporting unit below its carrying amount. Additional information pertaining to our accounting policy for goodwill and other intangible assets is summarized in Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Goodwill and Other Intangible Assets.” We conducted a qualitative analysis as of October 1, 2018 and concluded that it was not more likely than not that the fair values of our reporting units were less than their respective carrying values. As such, goodwill was not impaired. During the most recent quantitative assessment in 2017, we determined that the estimated fair value of the Key Community Bank unit was 48% greater than its carrying amount and the estimated fair value of the Key Corporate Bank unit was 39% greater than its carrying amount. The carrying amounts of the Key Community Bank and Key Corporate Bank units represent the average equity based on risk-weighted regulatory capital for goodwill impairment testing and management reporting purposes. Based on our quarterly review of impairment indicators during 2018 and 2017 , it was not necessary to perform further reviews of goodwill recorded in our Key Community Bank or Key Corporate Bank units. We will continue to monitor the Key Community Bank and Key Corporate Bank units as appropriate. Changes in the carrying amount of goodwill by reporting unit are presented in the following table: in millions Key Community Bank Key Corporate Bank Total BALANCE AT DECEMBER 31, 2016 $ 2,088 $ 358 $ 2,446 Fair value measurement adjustments - First Niagara acquisition 15 3 18 Additional ownership interest in Key Merchant Services 4 — 4 Acquisition of HelloWallet 17 — 17 Acquisition of Cain Brothers — 53 53 BALANCE AT DECEMBER 31, 2017 2,124 414 2,538 KIBS divestiture (22 ) — (22 ) BALANCE AT DECEMBER 31, 2018 $ 2,102 $ 414 $ 2,516 Additional information regarding the above acquisitions and divestiture is provided in Note 14 (“ Acquisitions, Divestiture, and Discontinued Operations ”). As of December 31, 2018 , we expect goodwill in the amount of $540 million to be deductible for tax purposes in future periods. There were no accumulated impairment losses related to the Key Community Bank unit or the Key Corporate Bank unit at December 31, 2018 , December 31, 2017 , and December 31, 2016 . The following table shows the gross carrying amount and the accumulated amortization of intangible assets subject to amortization: 2018 2017 December 31, in millions Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Intangible assets subject to amortization: Core deposit intangibles $ 396 $ 184 $ 461 $ 192 PCCR intangibles 152 138 152 126 Other intangible assets 115 25 128 7 Total $ 663 $ 347 $ 741 $ 325 Intangible assets acquired during the year ended December 31, 2017, were as follows: in millions KMS HelloWallet Cain Brothers Total Intangible assets subject to amortization: Customer relationships $ 85 — $ 29 $ 114 Trade name — — 1 1 Proprietary software — $ 12 — 12 Total $ 85 $ 12 $ 30 $ 127 Acquired customer relationships of KMS are being amortized over an estimated useful life of ten years utilizing an accelerated method. Proprietary software intangible assets of HelloWallet are being amortized on a straight line basis over their average useful life of three years . Acquired customer relationships of Cain Brothers are being amortized on an accelerated basis over an average useful life of eight years . The Cain Brothers trade name intangible asset is being amortized on a straight line basis over the estimated useful life of three years . The following table presents estimated intangible asset amortization expense for the next five years. Estimated in millions 2019 2020 2021 2022 2023 Intangible asset amortization expense $ 80 $ 62 $ 52 $ 42 $ 34

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Variable Interest Entities	12. Variable Interest Entities A VIE is a partnership, limited liability company, trust, or other legal entity that meets any one of the following criteria: • The entity does not have sufficient equity to conduct its activities without additional subordinated financial support from another party. • The entity’s investors lack the power to direct the activities that most significantly impact the entity’s economic performance. • The entity’s equity at risk holders do not have the obligation to absorb losses or the right to receive residual returns. • The voting rights of some investors are not proportional to their economic interests in the entity, and substantially all of the entity’s activities involve, or are conducted on behalf of, investors with disproportionately few voting rights. Our significant VIEs are summarized below. We define a “significant interest” in a VIE as a subordinated interest that exposes us to a significant portion, but not the majority, of the VIE’s expected losses or residual returns, even though we do not have the power to direct the activities that most significantly impact the entity’s economic performance. LIHTC investments. Through KCDC, we have made investments directly and indirectly in LIHTC operating partnerships formed by third parties. As a limited partner in these operating partnerships, we are allocated tax credits and deductions associated with the underlying properties. We have determined that we are not the primary beneficiary of these investments because the general partners have the power to direct the activities that most significantly influence the economic performance of their respective partnerships and have the obligation to absorb expected losses and the right to receive residual returns. As we are not the primary beneficiary of these investments, we do not consolidate them. Our maximum exposure to loss in connection with these partnerships consists of our unamortized investment balance plus any unfunded equity commitments and tax credits claimed but subject to recapture. We had $1.4 billion and $1.3 billion of investments in LIHTC operating partnerships at December 31, 2018 , and December 31, 2017 , respectively. These investments are recorded in “accrued income and other assets” on our balance sheet. We do not have any loss reserves recorded related to these investments because we believe the likelihood of any loss is remote. For all legally binding unfunded equity commitments, we increase our recognized investment and recognize a liability. As of December 31, 2018 , and December 31, 2017 , we had liabilities of $532 million and $476 million , respectively, related to investments in qualified affordable housing projects, which are recorded in “accrued expense and other liabilities” on our balance sheet. We continue to invest in these LIHTC operating partnerships. The assets and liabilities presented in the table below convey the size of KCDC’s direct and indirect investments at December 31, 2018 , and December 31, 2017 . As these investments represent unconsolidated VIEs, the assets and liabilities of the investments themselves are not recorded on our balance sheet. Unconsolidated VIEs in millions Total Assets Total Liabilities Maximum Exposure to Loss December 31, 2018 LIHTC investments $ 5,932 $ 2,569 $ 1,740 December 31, 2017 LIHTC investments $ 6,003 $ 2,943 $ 1,561 We amortize our LIHTC investments over the period that we expect to receive the tax benefits. In 2018 , we recognized $170 million of amortization and $166 million of tax credits associated with these investments within “income taxes” on our income statement. In 2017 , we recognized $ 172 million of amortization and $ 171 million of tax credits associated with these investments within “income taxes” on our income statement. We also recognized $12 million in LIHTC impairment expense related to tax reform and $3 million unrelated to tax reform within “other noninterest expense. Principal investments. Through our principal investing entity, KCC, we have made investments in private equity funds engaged in venture- and growth-oriented investing. As a limited partner to these funds, KCC records these investments at fair value and receives distributions from the funds in accordance with the funds’ partnership agreements. We are not the primary beneficiary of these investments as we do not hold the power to direct the activities that most significantly affect the funds’ economic performance. Such power rests with the funds’ general partners. In addition, we neither have the obligation to absorb the funds’ expected losses nor the right to receive their residual returns. Our voting rights are also disproportionate to our economic interests, and substantially all of the funds’ activities are conducted on behalf of investors with disproportionately few voting rights. Because we are not the primary beneficiary of these investments, we do not consolidate them. Our maximum exposure to loss associated with indirect principal investments consists of the investments’ fair value plus any unfunded equity commitments. The fair value of our indirect principal investments totaled $96 million and $124 million at December 31, 2018 , and December 31, 2017 , respectively. These investments are recorded in “other investments” on our balance sheet. Additional information on indirect principal investments is provided in Note 6 (“ Fair Value Measurements ”). The table below reflects the size of the private equity funds in which KCC was invested as well as our maximum exposure to loss in connection with these investments at December 31, 2018 . Unconsolidated VIEs in millions Total Assets Total Liabilities Maximum Exposure to Loss December 31, 2018 Indirect investments $ 19,659 $ 376 $ 122 December 31, 2017 Indirect investments $ 26,817 $ 292 $ 153 Through our principal investing entities, we have formed and funded operating entities that provide management and other related services to our investment company funds, which directly invest in portfolio companies. In return for providing services to our direct investment funds, these entities’ receive a minority equity interest in the funds. This minority equity ownership is recorded at fair value on the entities’ financial statements. Additional information on our direct principal investments is provided in Note 6 (“ Fair Value Measurements ”). While other equity investors manage the daily operations of these entities, we retain the power, through voting rights, to direct the activities of the entities that most significantly impact their economic performance. In addition, we have the obligation to absorb losses and the right to receive residual returns that could potentially be significant to these entities. As a result, we have determined that we are the primary beneficiary of these funds and have consolidated them since formation. The entities had no assets at December 31, 2018 . The entities had $4 million of assets at December 31, 2017 , that can only be used to settle the entities’ obligations. These assets were recorded in “cash and due from banks” and “accrued income and other assets” on our balance sheet. The entities had no liabilities at December 31, 2018 , and December 31, 2017 , and other equity investors have no recourse to our general credit. Other unconsolidated VIEs. We are involved with other various entities in the normal course of business which we have determined to be VIEs. We have determined that we are not the primary beneficiary of these VIEs because we do not have the power to direct the activities that most significantly impact their economic performance. Our assets associated with these unconsolidated VIEs totaled $248 million at December 31, 2018 , and $230 million at December 31, 2017 . These assets are recorded in “accrued income and other assets,” “other investments,” “securities available for sale,” and “loans, net of unearned income” on our balance sheet. We had liabilities totaling $2 million associated with these unconsolidated VIEs at December 31, 2018 , and $4 million at December 31, 2017 . These liabilities are recorded in “accrued expenses and other liabilities” on our balance sheet. We have excluded certain transactions with unconsolidated VIEs from the balances above where we determine our continuing involvement is not significant. In addition, where we only have a lending arrangement in the normal course of business with unconsolidated VIEs we present the balances related to the lending arrangements in Note 5 (“ Asset Quality

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	13. Income Taxes Income taxes included in the income statement are summarized below. We file a consolidated federal income tax return. Year ended December 31, in millions 2018 2017 2016 Currently payable: Federal $ 184 $ 334 $ 149 State 62 — 19 Total currently payable 246 334 168 Deferred: Federal 117 274 13 State (19 ) 29 (2 ) Total deferred 98 303 11 Total income tax (benefit) expense (a) $ 344 $ 637 $ 179 (a) There was no income tax (benefit) expense on securities transactions in 2018 , 2017 , and 2016 . Income tax expense excludes equity- and gross receipts-based taxes, which are assessed in lieu of an income tax in certain states in which we operate. These taxes, which are recorded in “noninterest expense” on the income statement, totaled $15 million in 2018 , $22 million in 2017 , and $18 million in 2016 . Significant components of our deferred tax assets and liabilities included in “accrued income and other assets” and “accrued expense and other liabilities,” respectively, on the balance sheet, are as follows: December 31, in millions 2018 2017 Allowance for loan and lease losses $ 232 $ 233 Employee benefits 170 147 Net unrealized securities losses 144 138 Federal net operating losses and credits 34 205 Fair value adjustments 41 63 Non-tax accruals 80 89 State net operating losses and credits 3 7 Other 221 223 Gross deferred tax assets 925 1,105 Less: Valuation Allowance 11 15 Total deferred tax assets 914 1,090 Leasing transactions 531 588 Other 161 182 Total deferred tax liabilities 692 770 Net deferred tax assets (liabilities) (a) $ 222 $ 320 (a) From continuing operations. On December 22, 2017, the TCJ Act was signed into law. This comprehensive tax legislation provided for significant changes to the U.S. Internal Revenue Code of 1986, as amended, that impacted corporate taxation requirements, such as the reduction in the federal corporate income tax rate from 35% to 21% effective January 1, 2018. The TCJ Act retained the low-income housing and research and development credits and repealed the corporate alternative minimum tax. Other relevant corporate changes include earlier recognition of certain revenue; accelerating expensing of investments in tangible property, including leasing assets; and limiting several deductions such as FDIC premiums, certain executive compensation, and meals and entertainment expenses. Key was required to re-value certain tax-related assets under the provisions of the TCJ Act at December 31, 2017. Under current U.S. GAAP, deferred tax assets and liabilities are to be adjusted for the effect of a change in tax laws or rates with the effect included in income from continuing operations in the reporting period that includes the enactment date. The tax-related assets consist primarily of deferred tax assets and liabilities and investments in low-income housing transactions. Due to the close proximity of our year end to the date the TCJ Act was signed into law, we estimated the impact of the income tax effects as of December 31, 2017, based upon currently available information which resulted in a reduction to our net income of $161 million . The significant components of this reduction included a $14 million reduction in our investments in certain low-income housing that is reflected in other expenses and a $147 million , or 7.6% , increase in our income tax provision for the twelve months ended December 31, 2017, due to the reduction to our net deferred tax asset and related actions. This reduction was primarily the result of the lower federal corporate income tax rate and was based on information available at that time. During the third quarter of 2018, Key completed and filed its 2017 federal income tax return and management finalized its assessment of the initial impact of the TCJ Act and related regulatory guidance. As a result, our income tax provision was increased by $7 million during the quarter and the total impact to Key of the TCJ Act was a reduction to our net income of $168 million . The accounting for the changes in tax law resulted in stranded tax effects within AOCI for items that were originally recognized in OCI rather than in net income. During the quarter ended December 31, 2017, we early adopted an ASU issued by the FASB allowing companies to reclassify stranded tax effects resulting from the TCJ Act from accumulated other comprehensive income to retained earnings. Utilizing the portfolio method, during the quarter ended December 31, 2017, we reclassified $141 million from accumulated other comprehensive income to retained earnings to eliminate the stranded tax effects. We conduct quarterly assessments of all available evidence to determine the amount of deferred tax assets that are more-likely-than-not to be realized, and therefore recorded. The available evidence used in connection with these assessments includes taxable income in prior periods, projected future taxable income, potential tax-planning strategies, and projected future reversals of deferred tax items. These assessments involve a degree of subjectivity and may undergo significant change. Based on these criteria, we have recorded $11 million of valuation allowances at December 31, 2018 ; primarily against federal and state capital loss carryforwards acquired in the First Niagara acquisition. At December 31, 2018 , we had federal net operating loss carryforwards of $61 million , federal credit carryforwards of $21 million , and capital loss carryforwards of $11 million . The federal net operating loss carryforwards are from prior acquisitions by First Niagara and are subject to annual limitations under the tax code and, if not utilized, will expire in the years beginning 2027. We currently expect to fully utilize these losses. The federal credit carryforward consists of general business credits which expire in 2037, under the Internal Revenue Code. The capital loss carryforward, if not utilized, will expire in 2019. Realization of this tax benefit is dependent upon Key’s ability to generate sufficient capital gain in an appropriate tax year to offset the capital loss carryforward. Currently, generation of sufficient capital gain income is uncertain. We had state net operating loss carryforwards of $54 million , and state credit carryforwards of $1 million , resulting in a net state deferred tax asset of $3 million . Additionally, we had state capital loss carryforwards of $1 million . These carryforwards, if not utilized, will gradually expire through 2031. The following table shows how our total income tax expense (benefit) and the resulting effective tax rate were derived: Year ended December 31, dollars in millions 2018 2017 2016 Amount Rate Amount Rate Amount Rate Income (loss) before income taxes times 21% (35% for 2017 and 2016) statutory federal tax rate $ 463 21.0 % $ 675 35.0 % $ 339 35.0 % Amortization of tax-advantaged investments 127 5.8 104 5.4 88 9.0 Foreign tax adjustments 2 .1 1 .1 1 .1 Tax-exempt interest income (30 ) (1.4 ) (37 ) (1.9 ) (25 ) (2.6 ) Corporate-owned life insurance income (29 ) (1.3 ) (46 ) (2.4 ) (44 ) (4.5 ) State income tax, net of federal tax benefit 34 1.5 19 1.0 11 1.1 Tax credits (234 ) (10.6 ) (218 ) (11.3 ) (208 ) (21.3 ) Tax Cuts and Jobs Act 7 .3 147 7.6 — — Other 4 .2 (8 ) (.5 ) 17 1.7 Total income tax expense (benefit) $ 344 15.6 % $ 637 33.0 % $ 179 18.5 % Liability for Unrecognized Tax Benefits The change in our liability for unrecognized tax benefits is as follows: Year ended December 31, 2018 2017 Balance at beginning of year $ 39 $ 53 Increase for other tax positions of prior years 15 3 Increase from Acquisitions — 3 Decrease for payments and settlements — (4 ) Decrease related to tax positions taken in prior years (19 ) (16 ) Balance at end of year $ 35 $ 39 Each quarter, we review the amount of unrecognized tax benefits recorded in accordance with the applicable accounting guidance. Any adjustment to unrecognized tax benefits is recorded in income tax expense. The amount of unrecognized tax benefits that, if recognized, would affect our effective tax rate was $35 million at December 31, 2018 , and $39 million at December 31, 2017 . We do not currently anticipate that the amount of unrecognized tax benefits will significantly change over the next 12 months . As permitted under the applicable accounting guidance, it is our policy to record interest and penalties related to unrecognized tax benefits in income tax expense. We recorded net interest benefit of $.7 million and $1.3 million in 2018 and 2017 , respectively and net interest expense of $.4 million in 2016 . We did not recover any state tax penalties in 2018 or 2016 . We recovered state tax penalties of $1 million in 2017. At December 31, 2018 , we had an accrued interest payable of $3 million , compared to $4 million at December 31, 2017 . There was no liability for accrued state tax penalties at December 31, 2018 , and December 31, 2017 . The amount of unrecognized tax benefits to be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss or a tax credit carryforward if certain criteria are met at December 31, 2018 , and December 31, 2017 , are $14.3 million and $17.2 million , respectively. We file federal income tax returns, as well as returns in various state and foreign jurisdictions. We are subject to income tax examination by the IRS for the tax years 2013 and forward. Currently, we are under IRS audit for the tax years 2013 and 2014. We are not subject to income tax examinations by other tax authorities for years prior to 2009. Pre-1988 Bank Reserves acquired in a business combination Retained earnings of KeyBank included approximately $92 million

Acquisition, Divestiture, and D

Acquisition, Divestiture, and Discontinued Operations	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Acquisition, Divestiture, and Discontinued Operations	14. Acquisitions, Divestiture, and Discontinued Operations Acquisitions Laurel Road Bank. On January 16, 2019, we announced that KeyBank has entered into a definitive agreement with Laurel Road Bank to acquire Laurel Road's digital lending business. Laurel Road's three bank branches located in southeast Connecticut are not part of this transaction. Through the acquisition, KeyBank expects to enhance its digital capabilities with state-of-the-art, customer-centric technology and to leverage Laurel Road's proven ability to attract and serve professional millennial clients. The acquisition is subject to customary closing conditions, including regulatory approvals. Cain Brothers & Company, LLC. On October 2, 2017, KBCM acquired all outstanding interests in Cain Brothers, a healthcare-focused investment banking and public finance firm. This acquisition expanded KBCM’s investment banking group in the healthcare vertical by adding distinctive capabilities and broadening KBCM’s existing healthcare investment banking network. The acquisition was accounted for as a business combination. During the fourth quarter of 2017, Key recognized estimated identifiable intangible assets of $30 million and goodwill of $53 million as a result of this acquisition, which are deductible for tax purposes. The valuation of the acquired assets and liabilities of Cain Brothers was final at March 31, 2018. HelloWallet Holdings, Inc. On July 1, 2017, KeyBank acquired all of the outstanding capital stock of HelloWallet Holdings, Inc., the sole owner of HelloWallet, LLC, a digital financial wellness company. Key’s retail banking franchise is leveraging HelloWallet’s technology to provide data-driven insights to clients, allowing clients to better understand and improve their personal finances. The acquisition was accounted for as a business combination. As a result, Key recognized identifiable intangible assets with an estimated fair value of $12 million , comprised primarily of propriety software and goodwill of $17 million , which are not deductible for tax purposes. The valuation of the acquired assets and liabilities of HelloWallet was final at March 31, 2018. Key Merchant Services, LLC. On June 30, 2017, KeyBank (consolidated) acquired an additional 51% interest in KMS, increasing our ownership interest from 49% to 100% . This acquisition enables us to grow our merchant services business and enhance our merchant product offerings. This transaction was accounted for as a business combination achieved in stages. Prior to the acquisition, KMS was operated as a merchant services joint venture and accounted for as an equity method investment in our consolidated financial statements. As of June 30, 2017, the provisional estimated fair value of our equity interest in KMS immediately before the acquisition was $74 million . The fair value of our previously held equity interest was measured using discounted cash flow modeling that incorporates an appropriate risk premium and forecast earnings information. On June 30, 2017, we recognized a provisional non-cash holding gain of $64 million for the difference between the fair value and the book value of our previously held equity interest. In the third quarter of 2017, we recognized a measurement-period adjustment of $5 million to reduce the provisional estimated fair value of our equity interest immediately before the acquisition to $69 million , which reduced the total non-cash holding gain to $59 million . The initial gain and subsequent adjustment were included in “other income” on the income statement for the twelve months ended December 31, 2017 . Upon acquisition, we recorded provisional identifiable intangible assets of $95 million and goodwill of less than $1 million . In the third quarter of 2017, we recognized a measurement-period adjustment of $10 million to reduce the fair value of acquired identifiable intangible assets to $85 million . In the fourth quarter of 2017, we recognized a measurement period adjustment increasing deferred tax assets and decreasing goodwill by $2 million . In aggregate, the measurement-period adjustments recognized as of December 31, 2017 increased goodwill recorded in connection with the KMS acquisition to $4 million . The valuation of the acquired assets and liabilities of KMS was final at June 30, 2018. Divestitures Key Insurance & Benefits Services, Inc. On March 29, 2018, we announced that we had entered into a definitive agreement to sell KIBS to USI Insurance Services. We acquired KIBS as a part of the 2016 merger with First Niagara. We completed the sale to USI Insurance Services on May 4, 2018. At the close of the sale, we recognized a $73 million net gain on sale. In the third quarter of 2018, we recognized an additional $5 million gain upon the finalization of the net working capital. Discontinued operations Discontinued operations includes our government-guaranteed and private education lending business. At December 31, 2018 , and December 31, 2017 , approximately $1.1 billion and $1.3 billion

Securities Financing Activities

Securities Financing Activities	12 Months Ended
	Dec. 31, 2018
Brokers and Dealers [Abstract]
Securities Financing Activities	15. Securities Financing Activities The following table summarizes our securities financing agreements at December 31, 2018 , and December 31, 2017 : December 31, 2018 December 31, 2017 in millions Gross Amount Presented in Balance Sheet Netting Adjustments (a) Collateral (b) Net Amounts Gross Amount Presented in Balance Sheet Netting Adjustments (a) Collateral (b) Net Amounts Offsetting of financial assets: Reverse repurchase agreements $ 14 $ (14 ) $ — — $ 3 $ (3 ) — — Total $ 14 $ (14 ) $ — — $ 3 $ (3 ) — — Offsetting of financial liabilities: Repurchase agreements (c) $ 319 $ (14 ) $ (305 ) — $ 374 $ (4 ) $ (370 ) — Total $ 319 $ (14 ) $ (305 ) — $ 374 $ (4 ) $ (370 ) — (a) Netting adjustments take into account the impact of master netting agreements that allow us to settle with a single counterparty on a net basis. (b) These adjustments take into account the impact of bilateral collateral agreements that allow us to offset the net positions with the related collateral. The application of collateral cannot reduce the net position below zero. Therefore, excess collateral, if any, is not reflected above. (c) Repurchase agreements are collateralized by mortgaged-backed agency securities and are contracted on an overnight or continuous basis. As of December 31, 2018 , the carrying amount of assets pledged as collateral against repurchase agreements totaled $892 million . Assets pledged as collateral are reported in “available for sale” and “held-to-maturity” securities on our balance sheet. At December 31, 2018 , the liabilities associated with collateral pledged were solely comprised of customer sweep financing activity and had a carrying value of $304 million . The collateral pledged under customer sweep repurchase agreements is posted to a third-party custodian and cannot be sold or repledged by the secured party. The risk related to a decline in the market value of collateral pledged is minimal given the collateral's high credit quality and the overnight duration of the repurchase agreements.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	16. Stock-Based Compensation We maintain several stock-based compensation plans, which are described below. Total compensation expense for these plans was $99 million for 2018 , $104 million for 2017 , and $102 million for 2016 . The total income tax benefit recognized in the income statement for these plans was $23 million for 2018 , $39 million for 2017 , and $38 million for 2016 . Our compensation plans allow us to grant stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, other awards which may be denominated or payable in or valued by reference to our Common Shares or other factors, discounted stock purchases, and deferred compensation to eligible employees and directors. At December 31, 2018 , we had 24,147,422 Common Shares available for future grant under our compensation plans. In accordance with a resolution adopted by the Compensation and Organization Committee of KeyCorp’s Board of Directors, we may not grant options to purchase Common Shares, restricted stock or other shares under any long-term compensation plan in an aggregate amount that exceeds 6% of our outstanding Common Shares in any rolling three -year period. Stock Options Stock options granted to employees generally become exercisable at the rate of 25% per year. No option granted by KeyCorp will be exercisable less than one year after, or expire later than ten years from, the grant date. The exercise price is the closing price of our Common Shares on the grant date. We determine the fair value of options granted using the Black-Scholes option-pricing model. This model was originally developed to determine the fair value of exchange-traded equity options, which (unlike employee stock options) have no vesting period or transferability restrictions. Because of these differences, the Black-Scholes model does not precisely value an employee stock option, but it is commonly used for this purpose. The model assumes that the estimated fair value of an option is amortized as compensation expense over the option’s vesting period. The Black-Scholes model requires several assumptions, which we developed and update based on historical trends and current market observations. Our determination of the fair value of options is only as accurate as the underlying assumptions. The assumptions pertaining to options issued during 2018 , 2017 , and 2016 are shown in the following table. Year ended December 31, 2018 2017 2016 Average option life 6.5 years 6.0 years 6.0 years Future dividend yield 2.28 % 1.79 % 2.86 % Historical share price volatility .282 .287 .297 Weighted-average risk-free interest rate 2.8 % 2.1 % 1.3 % Under KeyCorp’s 2013 Equity Compensation Plan, the Compensation and Organization Committee has authority to approve all stock option grants but may delegate some of its authority to grant awards from time to time. The committee has delegated to our Chief Executive Officer the authority to grant equity awards, including stock options, to any employee who is not designated an “officer” for purposes of Section 16 of the Exchange Act. No more than 3,000,000 Common Shares may be issued under this authority. The following table summarizes activity, pricing and other information for our stock options for the year ended December 31, 2018 : Number of Options Weighted-Average Exercise Price Per Option Weighted-Average Remaining Life Aggregate Intrinsic Value (a) Outstanding at December 31, 2017 9,882,617 $ 11.28 5.5 years $ 88 Granted 346,088 21.02 Exercised (1,960,444 ) 10.12 Lapsed or canceled (144,417 ) 14.37 Outstanding at December 31, 2018 8,123,844 $ 11.92 5.3 31 Expected to vest 2,508,684 15.09 7.6 5 Exercisable at December 31, 2018 5,479,638 $ 10.36 4.2 $ 26 (a) The intrinsic value of a stock option is the amount by which the fair value of the underlying stock exceeds the exercise price of the option. The weighted-average grant-date fair value of options was $5.12 for options granted during 2018 , $4.6 for options granted during 2017 , and $2.14 for options granted during 2016 . Stock option exercises numbered 1,960,444 in 2018 , 3,755,177 in 2017 , and 2,849,010 in 2016 . The aggregate intrinsic value of exercised options was $21 million for 2018 , $31 million for 2017 , and $12 million for 2016 . As of December 31, 2018 , unrecognized compensation cost related to nonvested options under the plans totaled $2 million . We expect to recognize this cost over a weighted-average period of 2.0 years . Cash received from options exercised was $20 million , $25 million , and $32 million in 2018 , 2017 , and 2016 , respectively. The actual tax benefit realized for the tax deductions from options exercised totaled $1 million for 2018 , $4 million for 2017 , and $2 million for 2016 . Long-Term Incentive Compensation Program Our Long-Term Incentive Compensation Program (the “Program”) rewards senior executives critical to our long-term financial success. Awards are granted annually in a variety of forms: • deferred cash payments that generally vest and are payable at the rate of 25% per year; • time-lapsed (service condition) restricted stock units payable in stock, which generally vest at the rate of 25% per year; • performance units payable in stock, which vest at the end of the three -year performance cycle and will not vest unless Key attains defined performance levels; and • performance units payable in cash, which vest at the end of the three -year performance cycle and will not vest unless Key attains defined performance levels. During 2018 , the total of performance units vested numbered 1,070,112 , which were payable in stock and cash. The total fair value of the performance units that vested during 2018 was $19 million . During 2017 , the performance units vested numbered 887,489 which were payable in stock and cash. The total fair value of of the performance units that vested during 2017 was $14 million . The following table summarizes activity and pricing information for the nonvested shares in the Program for the year ended December 31, 2018 . Vesting Contingent on Service Conditions Vesting Contingent on Performance and Service Conditions Number of Nonvested Shares Weighted- Average Grant-Date Fair Value Number of Nonvested Shares Weighted- Average Grant-Date Fair Value Outstanding at December 31, 2017 11,832,956 $ 14.05 4,148,020 $ 17.51 Granted 4,076,746 21.02 1,588,738 14.83 Vested (5,404,616 ) 13.61 (1,070,112 ) 17.73 Forfeited (930,136 ) 17.01 (127,191 ) 19.42 Outstanding at December 31, 2018 9,574,950 $ 16.84 4,539,455 $ 14.35 The compensation cost of time-lapsed and performance-based restricted stock or unit awards granted under the Program is calculated using the closing trading price of our Common Shares on the grant date. Unlike time-lapsed and performance-based restricted stock or units, we do not pay dividends during the vesting period for performance shares or units that may become payable in excess of targeted performance. The weighted-average grant-date fair value of awards granted under the Program was $19.28 during 2018 , $19.82 during 2017 , and $10.49 during 2016 . As of December 31, 2018 , unrecognized compensation cost related to nonvested shares under the Program totaled $73 million . We expect to recognize this cost over a weighted-average period of 2.4 years . The total fair value of shares vested was $93 million in 2018 , $76 million in 2017 , and $57 million in 2016 . Deferred Compensation and Other Restricted Stock Awards Our deferred compensation arrangements include voluntary and mandatory deferral programs for Common Shares awarded to certain employees and directors. Mandatory deferred incentive awards vest at the rate of 25% per year beginning one year after the deferral date for awards granted in 2012 and after. Deferrals under the voluntary programs are immediately vested. We also may grant, upon approval by the Compensation and Organization Committee (or our Chief Executive Officer with respect to her delegated authority), other time-lapsed restricted stock or unit awards under various programs to recognize outstanding performance. The following table summarizes activity and pricing information for the nonvested shares granted under our deferred compensation plans and these other restricted stock or unit award programs for the year ended December 31, 2018 . Number of Nonvested Shares Weighted-Average Grant-Date Fair Value Outstanding at December 31, 2017 4,223,774 $ 15.61 Granted 724,287 20.77 Dividend equivalents 18 20.03 Vested (1,523,387 ) 14.43 Forfeited (144,875 ) 14.18 Outstanding at December 31, 2018 3,279,817 $ 17.36 The weighted-average grant-date fair value of awards granted was $20.77 during 2018 , $18.55 during 2017 , and $11.46 during 2016 . As of December 31, 2018 , unrecognized compensation cost related to nonvested shares granted under our deferred compensation plans and the other restricted stock or unit award programs totaled $21 million . We expect to recognize this cost over a weighted-average period of 2.9 years . The total fair value of shares vested was $22 million in 2018 , $21 million in 2017 , and $16 million in 2016 . Dividend equivalents presented in the preceding table represent the value of dividends accumulated during the vesting period. Discounted Stock Purchase Plan Our Discounted Stock Purchase Plan provides employees the opportunity to purchase our Common Shares at a 10% discount through payroll deductions or cash payments. Purchases are limited to $10,000 in any month and $50,000 in any calendar year, and are immediately vested. To accommodate employee purchases, we issue treasury shares on or around the fifteenth day of the month following the month employee payments are received. We issued 327,435 Common Shares at a weighted-average cost to employees of $17.48 during 2018 , 257,738 Common Shares at a weighted-average cost to employees of $16.61 during 2017 , and 310,604 Common Shares at a weighted-average cost to employees of $11.04 during 2016 . Information pertaining to our method of accounting for stock-based compensation is included in Note 1 (“ Summary of Significant Accounting Policies

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Employee Benefits	17. Employee Benefits Pension Plans Effective December 31, 2009, we amended our cash balance pension plan and other defined benefit plans to freeze all benefit accruals and close the plans to new employees. We will continue to credit participants’ existing account balances for interest until they receive their plan benefits. We changed certain pension plan assumptions after freezing the plans. As part of the acquisition of First Niagara, Key also obtained two frozen defined benefit plans sponsored by First Niagara, both of which provide benefits based upon length of service and compensation levels. Effective September 30, 2016, the two First Niagara plans merged into another defined benefit plan maintained by Key to form the KeyCorp Consolidated Cash Balance Plan. Effective December 31, 2016, our original cash balance pension plan merged into the KeyCorp Consolidated Cash Balance Plan. Pre-tax AOCI not yet recognized as net pension cost was $511 million at December 31, 2018 , and $525 million at December 31, 2017 , consisting entirely of net unrecognized losses. During 2019 , we expect to recognize $13 million of net unrecognized losses in pre-tax AOCI as net pension cost. During 2018 and 2016 , lump sum payments made under certain pension plans triggered settlement accounting. In accordance with the applicable accounting guidance for defined benefit plans, we performed a remeasurement of the affected plans in conjunction with the settlement and recognized the settlement loss as reflected in the following table. The components of net pension cost and the amount recognized in OCI for all funded and unfunded plans are as follows: Year ended December 31, in millions 2018 2017 2016 Interest cost on PBO $ 41 $ 48 $ 44 Expected return on plan assets (53 ) (68 ) (58 ) Amortization of losses 17 15 17 Settlement loss 17 — 18 Net pension cost $ 22 $ (5 ) $ 21 Other changes in plan assets and benefit obligations recognized in OCI: Net (gain) loss $ 20 $ (10 ) $ (9 ) Amortization of gains (33 ) (15 ) (35 ) Total recognized in comprehensive income $ (13 ) $ (25 ) $ (44 ) Total recognized in net pension cost and comprehensive income $ 9 $ (30 ) $ (23 ) The information related to our pension plans presented in the following tables is based on current actuarial reports using measurement dates of December 31, 2018 , and December 31, 2017 . The following table summarizes changes in the PBO related to our pension plans. Year ended December 31, in millions 2018 2017 PBO at beginning of year $ 1,323 $ 1,338 Interest cost 41 48 Actuarial losses (gains) (66 ) 37 Benefit payments (97 ) (100 ) PBO at end of year $ 1,201 $ 1,323 The following table summarizes changes in the FVA. Year ended December 31, in millions 2018 2017 FVA at beginning of year $ 1,163 $ 1,133 Actual return on plan assets (34 ) 115 Employer contributions 14 15 Benefit payments (97 ) (100 ) FVA at end of year $ 1,046 $ 1,163 The following table summarizes the funded status of the pension plans, which equals the amounts recognized in the balance sheets at December 31, 2018 , and December 31, 2017 . December 31, in millions 2018 2017 Funded status (a) $ (155 ) $ (160 ) Net prepaid pension cost recognized consists of: Noncurrent assets $ 17 29 Current liabilities (15 ) $ (15 ) Noncurrent liabilities (157 ) (174 ) Net prepaid pension cost recognized (b) $ (155 ) $ (160 ) (a) The shortage of the FVA under the PBO. (b) Represents the accrued benefit liability of the pension plans. At December 31, 2018 , our primary qualified cash balance pension plan was sufficiently funded under the requirements of ERISA. Consequently, we are not required to make a minimum contribution to that plan in 2019 . We also do not expect to make any significant discretionary contributions during 2019 . At December 31, 2018 , we expect to pay the benefits from all funded and unfunded pension plans as follows: 2019 — $112 million ; 2020 — $110 million ; 2021 — $110 million ; 2022 — $102 million ; 2023 — $98 million and $400 million in the aggregate from 2024 through 2028. The ABO for all of our pension plans was $1.2 billion at December 31, 2018 , and $1.3 billion at December 31, 2017 . As indicated in the table below, collectively our plans had an ABO in excess of plan assets as follows: December 31, in millions 2018 2017 PBO $ 1,201 $ 1,323 ABO 1,201 1,323 Fair value of plan assets 1,046 1,163 To determine the actuarial present value of benefit obligations, we assumed the following weighted-average rates. December 31, 2018 2017 Discount rate 4.00 % 3.25 % Compensation increase rate N/A N/A To determine net pension cost, we assumed the following weighted-average rates. Year ended December 31, 2018 2017 2016 Discount rate 3.25 % 3.75 % 3.75 % Compensation increase rate N/A N/A N/A Expected return on plan assets 4.75 6.00 6.00 We estimate that we will recognize $12 million in net pension cost for 2019, compared to net pension cost of $22 million in 2018, and net pension benefit of $5 million for 2017. A settlement loss was recorded in both 2018 and 2016 but not in 2017. We estimate that a 25 basis point increase or decrease in the expected return on plan assets would change our net pension cost for 2019 by approximately $3 million . Pension cost also is affected by an assumed discount rate. We estimate that a 25 basis point change in the assumed discount rate would change net pension cost for 2019 by approximately $1 million . The expected return on plan assets is determined by considering a number of factors, the most significant of which are: • Our expectations for returns on plan assets over the long term, weighted for the investment mix of the assets. These expectations consider, among other factors, historical capital market returns of equity, fixed income, convertible, and other securities, and forecasted returns that are modeled under various economic scenarios. • Historical returns on our plan assets. Based on an annual reassessment of current and expected future capital market returns, our expected return on plan assets was 4.75% for 2018 , 6% for 2017 and 6% for 2016 . As a result of a change in our investment allocation policy, we deemed a rate of 4.50% to be appropriate in estimating 2018 pension cost. The investment objectives of the pension fund are developed to reflect the characteristics of the plan, such as pension formulas, cash lump sum distribution features, and the liability profiles of the plan’s participants. An executive oversight committee reviews the plan’s investment performance at least quarterly, and compares performance against appropriate market indices. The pension fund’s investment objectives are to balance total return objectives with a continued management of plan liabilities, and to minimize the mismatch between assets and liabilities. These objectives are being implemented through liability driven investing and the adoption of a de-risking glide path. The following table shows the asset target allocations prescribed by the pension fund’s investment policies based on the plan’s funded status at December 31, 2018 . Target Allocation Asset Class 2018 Equity securities: U.S. 5 % International 4 Fixed income securities 81 Real assets 6 Other assets 4 Total 100 % Equity securities include common stocks of domestic and foreign companies, as well as foreign company stocks traded as American Depositary Shares on U.S. stock exchanges. Debt securities include investments in domestic- and foreign-issued corporate bonds, U.S. government and agency bonds, international government bonds, and mutual funds. Real assets include an investment in a diversified real asset strategy separate account designed to provide exposure to the three core real assets: Treasury Inflation-Protected Securities, commodities, and real estate. Other assets include investments in a multi-strategy investment fund and a limited partnership. Although the pension funds’ investment policies conditionally permit the use of derivative contracts, we have not entered into any such contracts, and we do not expect to employ such contracts in the future. The valuation methodologies used to measure the fair value of pension plan assets vary depending on the type of asset, as described below. For an explanation of the fair value hierarchy, see Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Fair Value Measurements.” Equity securities. Equity securities traded on securities exchanges are valued at the closing price on the exchange or system where the security is principally traded. These securities are classified as Level 1 since quoted prices for identical securities in active markets are available. Debt securities. Substantially all debt securities are investment grade and include domestic- and foreign-issued corporate bonds and U.S. government and agency bonds. These securities are valued using evaluated prices based on observable inputs, such as dealer quotes, available trade information, spreads, bids and offers, prepayment speeds, U.S. Treasury curves, and interest rate movements. Debt securities are classified as Level 2. Mutual funds. Exchange-traded mutual funds listed or traded on securities exchanges are valued at the closing price on the exchange or system where the security is principally traded. These securities are classified as Level 1 because quoted prices for identical securities in active markets are available. Collective investment funds. Investments in collective investment funds are valued using the net asset value practical expedient and are not classified within the fair value hierarchy. Fair value is determined based on Key’s proportionate share of total net assets in the fund. Insurance investment contracts and pooled separate accounts. Deposits under insurance investment contracts and pooled separate accounts with insurance companies do not have readily determinable fair values and are valued using a methodology that is consistent with accounting guidance that allows the plan to estimate fair value based upon net asset value per share (or its equivalent, such as member units or an ownership in partners’ capital to which a proportionate share of net assets is attributed); thus, these investments are not classified within the fair value hierarchy. Other assets. Other assets include an investment in a multi-strategy investment fund and an investment in a limited partnership. These investments do not have readily determinable fair values and are valued using a methodology consistent with accounting guidance that allows the plan to estimate fair value based upon net asset value per share (or its equivalent, such as member units or an ownership in partners’ capital to which a proportionate share of net assets is attributed); thus, these investments are not classified within the fair value hierarchy. The following tables show the fair values of our pension plan assets by asset class at December 31, 2018 , and December 31, 2017 . December 31, 2018 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Equity securities: Common — U.S. $ 6 — — $ 6 Preferred — U.S. 3 — — 3 Debt securities: Corporate bonds — U.S. — $ 157 — 157 Corporate bonds — International — 65 — 65 Government and agency bonds — U.S. — 180 — 180 Government bonds — International — 2 — 2 State and municipal bonds — 28 — 28 Mutual funds: Equity — International 1 — — 1 Collective investment funds (measured at NAV) (a) — — — 546 Insurance investment contracts and pooled separate accounts (measured at NAV) (a) — — — 16 Other assets (measured at NAV) (a) — — — 42 Total net assets at fair value $ 10 $ 432 — $ 1,046 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. December 31, 2017 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Equity securities: Common — U.S. 11 — — 11 Common — International 1 — — 1 Preferred — U.S. 3 — — 3 Debt securities: Corporate bonds — U.S. — $ 152 — 152 Corporate bonds — International — 61 — 61 Government and agency bonds — U.S. — 203 — 203 Government bonds — International — 2 — 2 State and municipal bonds — 31 — 31 Mutual funds: Equity — International 7 — — 7 Collective investment funds (measured at NAV) (a) — — — 628 Insurance investment contracts and pooled separate accounts (measured at NAV) (a) — — — 14 Other assets (measured at NAV) (a) — — — 50 Total net assets at fair value $ 22 $ 449 — $ 1,163 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. Other Postretirement Benefit Plans We sponsor a retiree healthcare plan in which all employees age 55 with five years of service (or employees age 50 with 15 years of service who are terminated under conditions that entitle them to a severance benefit) are eligible to participate. Participant contributions are adjusted annually. Key may provide a subsidy toward the cost of coverage for certain employees hired before 2001 with a minimum of 15 years of service at the time of termination. We use a separate VEBA trust to fund the retiree healthcare plan. Effective November 29, 2016, an unfunded retiree welfare plan previously sponsored by First Niagara merged into our current retiree healthcare plan. The components of pre-tax AOCI not yet recognized as net postretirement benefit cost are shown below. December 31, in millions 2018 2017 Net unrecognized losses (gains) $ (12 ) $ (12 ) Net unrecognized prior service credit — (1 ) Total unrecognized AOCI $ (12 ) $ (13 ) During 2019 , we expect to recognize $1 million of pre-tax AOCI resulting from prior service credit as a reduction of net postretirement benefit cost. The components of net postretirement benefit cost and the amount recognized in OCI for all funded and unfunded plans are as follows: December 31, in millions 2018 2017 2016 Service cost of benefits earned $ 1 $ 1 $ 1 Interest cost on APBO 2 3 2 Expected return on plan assets (2 ) (2 ) (2 ) Amortization of prior service credit (1 ) (1 ) (1 ) Amortization of gains (1 ) — — Net postretirement benefit $ (1 ) 1 — Other changes in plan assets and benefit obligations recognized in OCI: Net (gain) loss $ 1 $ (4 ) $ (4 ) Amortization of prior service credit 1 1 1 Amortization of losses — — — Total recognized in comprehensive income $ 2 $ (3 ) $ (3 ) Total recognized in net postretirement benefit cost and comprehensive income $ 1 $ (2 ) $ (3 ) The information related to our postretirement benefit plans presented in the following tables is based on current actuarial reports using measurement dates of December 31, 2018 , and December 31, 2017 . The following table summarizes changes in the APBO. Year ended December 31, in millions 2018 2017 APBO at beginning of year $ 69 $ 69 Service cost 1 1 Interest cost 2 3 Plan participants’ contributions 1 1 Actuarial losses (gains) (6 ) 3 Benefit payments (4 ) (8 ) APBO at end of year $ 63 $ 69 The following table summarizes changes in FVA. Year ended December 31, in millions 2018 2017 FVA at beginning of year $ 52 $ 50 Employer contributions — — Plan participants’ contributions 1 1 Benefit payments (4 ) (8 ) Actual return on plan assets (2 ) 9 FVA at end of year $ 47 $ 52 The following table summarizes the funded status of the postretirement plans, which corresponds to the amounts recognized in the balance sheets at December 31, 2018 , and December 31, 2017 . December 31, in millions 2018 2017 Funded status (a) $ (17 ) $ (16 ) Accrued postretirement benefit cost recognized (b) (17 ) (16 ) (a) The shortage of the FVA under the APBO. (b) Consists entirely of noncurrent liabilities. There are no regulations that require contributions to the VEBA trust that funds our retiree healthcare plan, so there is no minimum funding requirement. We are permitted to make discretionary contributions to the VEBA trust, subject to certain IRS restrictions and limitations. We anticipate that our discretionary contributions in 2019 , if any, will be minimal. At December 31, 2018 , we expect to pay the benefits from other postretirement plans as follows: 2019 — $5 million ; 2020 — $5 million ; 2021 — $5 million ; 2022 — $5 million ; 2023 — $5 million ; and $22 million in the aggregate from 2024 through 2028. To determine the APBO, we assumed discount rates of 4.00% at December 31, 2018 , and 3.5% at December 31, 2017 . To determine net postretirement benefit cost, we assumed the following weighted-average rates. Year ended December 31, 2018 2017 2016 Discount rate 3.50 % 3.75 % 4.00 % Expected return on plan assets 4.50 4.50 4.50 The realized net investment income for the postretirement healthcare plan VEBA trust is subject to federal income taxes, which are reflected in the weighted-average expected return on plan assets shown above. Assumed healthcare cost trend rates do not have a material impact on net postretirement benefit cost or obligations since the postretirement plan has cost-sharing provisions and benefit limitations. We do no t expect to recognize a credit or an expense in net postretirement benefit cost for 2019 . We recognized a credit of $1 million in 2018 and a credit of less than $1 million in 2017 . We estimate the expected returns on plan assets for the VEBA trust much the same way we estimate returns on our pension funds. The primary investment objectives of the VEBA trust are to obtain a market rate of return, take into consideration the safety and/or risk of the investment, and to diversify the portfolio in order to satisfy the trust’s anticipated liquidity requirements. The following table shows the asset target allocations prescribed by the trust’s investment policy. Target Allocation Asset Class 2018 Equity securities 80 % Fixed income securities 20 Cash equivalents — Total 100 % Investments consist of mutual funds and collective investment funds that invest in underlying assets in accordance with the target asset allocations shown above. Exchange-traded mutual funds are valued using quoted prices and, therefore, are classified as Level 1. Investments in collective investment funds are valued using the Net Asset Value practical expedient and are not classified within the fair value hierarchy. The following tables show the fair values of our postretirement plan assets by asset class at December 31, 2018 , and December 31, 2017 . December 31, 2018 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Mutual funds: Equity — U.S. $ 21 — — $ 21 Equity — International 8 — — 8 Fixed income — U.S. 7 — — 7 Collective investment funds: Equity — U.S. (a) — — — 9 Other assets (measured at NAV) (a) — — — 2 Total net assets at fair value $ 36 — — $ 47 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. December 31, 2017 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Mutual funds: Equity — U.S. $ 25 — — $ 25 Equity — International 10 — — 10 Fixed income — U.S. 4 — — 4 Fixed income — International 3 — — 3 Collective investment funds: Equity — U.S. (a) — $ — — 10 Total net assets at fair value $ 42 $ — — $ 52 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. The Medicare Prescription Drug, Improvement and Modernization Act of 2003 introduced a prescription drug benefit under Medicare and prescribes a federal subsidy to sponsors of retiree healthcare benefit plans that offer prescription drug coverage that is “actuarially equivalent” to the benefits under Medicare Part D. Based on our application of the relevant regulatory formula, we determined that the prescription drug coverage related to our retiree healthcare benefit plan is not actuarially equivalent to the Medicare benefit for the vast majority of retirees. For the years ended December 31, 2018 , and December 31, 2017 , we did not receive federal subsidies. Employee 401(k) Savings Plan A substantial number of our employees are covered under a savings plan that is qualified under Section 401(k) of the Internal Revenue Code. The plan permits employees to contribute from 1% to 100% of eligible compensation, with up to 6% being eligible for matching contributions. Commencing January 1, 2010, an automatic enrollment feature was added to the plan for all new employees. The initial default contribution percentage for employees is 2% and will increase by 1% at the beginning of each plan year until the default contribution is 10% for plan years on and after January 1, 2012. The plan also permits us to provide a discretionary annual profit sharing contribution to eligible employees who have at least one year of service. First Niagara employees who joined Key retained their years of services, and those employees that met eligibility requirements under Key’s savings plan have been included. We accrued a 2% contribution for 2018 and made contributions of 2% and 2.5% for 2017 and 2016 , respectively, on eligible compensation for employees eligible on the last business day of the respective plan years. In addition to the discretionary annual profit sharing contribution, in 2017 we accrued a one-time $1,000 contribution per eligible full-time employee and $500 per eligible part-time employee within the 401(k) savings plan. Employees eligible for the additional contribution must have been employed as of December 31, 2017 and have a salary of $100,000 or less. We also maintain a deferred savings plan that provides certain employees with benefits they otherwise would not have been eligible to receive under the qualified plan once their compensation for the plan year reached the IRS contribution limits. Total expense associated with the above plans was $106 million in 2018 , $129 million in 2017 , and $94 million in 2016

Short-Term Borrowings

Short-Term Borrowings	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Short-Term Borrowings	18. Short-Term Borrowings Selected financial information pertaining to the components of our short-term borrowings is as follows: December 31, dollars in millions 2018 2017 2016 FEDERAL FUNDS PURCHASED Balance at year end — $ 3 $ 1,005 Average during the year $ 537 128 44 Maximum month-end balance 3,197 2,331 1,005 Weighted-average rate during the year (a) 1.68 % .72 % .68 % Weighted-average rate at December 31 (a) — — .55 SECURITIES SOLD UNDER REPURCHASE AGREEMENTS Balance at year end $ 319 $ 374 $ 497 Average during the year 391 389 443 Maximum month-end balance 614 472 684 Weighted-average rate during the year (a) .09 % .08 % .04 % Weighted-average rate at December 31 (a) .09 .08 .07 OTHER SHORT-TERM BORROWINGS Balance at year end $ 544 $ 634 $ 808 Average during the year 915 1,140 852 Maximum month-end balance 1,133 1,242 872 Weighted-average rate during the year (a) 2.34 % 1.34 % 1.18 % Weighted-average rate at December 31 (a) 2.92 2.01 1.11 (a) Rates exclude the effects of interest rate swaps and caps, which modify the repricing characteristics of certain short-term borrowings. For more information about such financial instruments, see Note 8 (“ Derivatives and Hedging Activities ”). As described below and in Note 19 (“ Long-Term Debt ”), KeyCorp and KeyBank have a number of programs and facilities that support our short-term financing needs. Certain subsidiaries maintain credit facilities with third parties, which provide alternative sources of funding. KeyCorp is the guarantor of some of the third-party facilities. Short-term credit facilities. We maintain cash on deposit in our Federal Reserve account, which has reduced our need to obtain funds through various short-term unsecured money market products. This account, which was maintained at $2.1 billion at December 31, 2018 , and the unpledged securities in our investment portfolio provide a buffer to address unexpected short-term liquidity needs. We also have secured borrowing facilities at the FHLB and the Federal Reserve Bank of Cleveland to satisfy short-term liquidity requirements. As of December 31, 2018 , our unused secured borrowing capacity was $25.4 billion at the Federal Reserve Bank of Cleveland and $7.5 billion

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Long-Term Debt	19. Long-Term Debt The following table presents the components of our long-term debt, net of unamortized discounts and adjustments related to hedging with derivative financial instruments. We use interest rate swaps and caps, which modify the repricing characteristics of certain long-term debt, to manage interest rate risk. For more information about such financial instruments, see Note 8 (“ Derivatives and Hedging Activities ”). December 31, dollars in millions 2018 2017 Senior medium-term notes due through 2021 (a) $ 3,278 $ 2,766 3.136% Subordinated notes due 2028 (b) 162 161 6.875% Subordinated notes due 2029 (b) 104 109 7.75% Subordinated notes due 2029 (b) 135 141 7.25% Subordinated notes due 2021 (c) 336 348 6.75% Senior notes due 2020 (d) 315 327 Other subordinated notes (b), (e) 70 69 Total parent company 4,400 3,921 Senior medium-term notes due through 2039 (f) 7,022 8,011 3.18% Senior remarketable notes due 2027 (g) 212 202 4.625% Subordinated notes due 2018 (h) — 100 3.40% Subordinated notes due 2026 (h) 560 565 6.95% Subordinated notes due 2028 (h) 299 299 Secured borrowing due through 2025 (i) 10 24 Federal Home Loan Bank advances due through 2038 (j) 1,130 1,106 Investment Fund Financing due through 2052 (k) 83 88 Obligations under Capital Leases due through 2032 (l) 16 17 Total subsidiaries 9,332 10,412 Total long-term debt $ 13,732 $ 14,333 (a) Senior medium-term notes had a weighted-average interest rate of 4.057% at December 31, 2018 , and 3.56% at December 31, 2017 . These notes had fixed interest rates at December 31, 2018 , and December 31, 2017 . These notes may not be redeemed prior to their maturity dates. (b) See Note 20 (“ Trust Preferred Securities Issued by Unconsolidated Subsidiaries ”) for a description of these notes. (c) The First Niagara subordinated debt had a weighted-average interest rate of 7.25% at December 31, 2018 , and a weighted-average interest rate of 7.25% at December 31, 2017 . These notes may not be redeemed prior to their maturity dates. (d) The First Niagara senior notes had a weighted-average interest rate of 6.75% at December 31, 2018 , and a weighted-average interest rate of 6.75% at December 31, 2017 . These notes may not be redeemed prior to their maturity dates. (e) The First Niagara variable rate trust preferred securities had a weighted-average interest rate of 4.20% at December 31, 2018 , and 3.022% at December 31, 2017 . These notes may be redeemed prior to their maturity dates. (f) Senior medium-term notes had weighted-average interest rates of 2.593% at December 31, 2018 , and 2.24% at December 31, 2017 . These notes are a combination of fixed and floating rates. These notes may not be redeemed prior to their maturity dates. (g) The remarketable senior medium-term notes had a weighted-average interest rate of 3.18% at December 31, 2018 , and 3.18% at December 31, 2017 . These notes had fixed interest rates at December 31, 2017, and December 31, 2018. These notes may not be redeemed prior to their maturity dates. (h) These notes are all obligations of KeyBank and may not be redeemed prior to their maturity dates. (i) The secured borrowing had weighted-average interest rates of 4.455% at December 31, 2018 , and 4.460% at December 31, 2017 . This borrowing is collateralized by commercial lease financing receivables, and principal reductions are based on the cash payments received from the related receivables. Additional information pertaining to these commercial lease financing receivables is included in Note 4 (“ Loan Portfolio ”). (j) Long-term advances from the Federal Home Loan Bank had a weighted-average interest rate of 2.333% at December 31, 2018 , and 2.318% at December 31, 2017 . These advances, which had fixed interest rates, were secured by real estate loans and securities totaling $1.1 billion at December 31, 2018 , and $1.1 billion at December 31, 2017 . (k) Investment Fund Financing had a weighted-average interest rate of 1.85% at December 31, 2018 , and 1.94% at December 31, 2017 . (l) These are capital leases acquired in the First Niagara merger with a maturity range from June 2019 through October 2032. At December 31, 2018 , scheduled principal payments on long-term debt were as follows: in millions Parent Subsidiaries Total 2019 — $ 2,262 $ 2,262 2020 $ 1,298 1,396 2,694 2021 1,350 1,744 3,094 2022 — 1,469 1,469 2023 — 456 456 All subsequent years 1,752 2,005 3,757 As described below, KeyBank and KeyCorp have a number of programs that support our long-term financing needs. Global bank note program. On September 29, 2015, KeyBank updated its Global Bank Note Program, authorizing the issuance of up to $20 billion of notes domestically and abroad. Under the program, KeyBank is authorized to issue notes with original maturities of seven days or more for senior notes or five years or more for subordinated notes. Notes may be denominated in U.S. dollars or in foreign currencies. Amounts outstanding under the program and any prior bank note programs are classified as “long-term debt” on the balance sheet. In 2017, KeyBank issued the following notes under the 2015 Global Bank Note Program: on June 9, 2017, $600 million of 2.40% Senior Bank Notes due June 9, 2022; and on September 14, 2017, $750 million of 2.30% Senior Bank Notes due September 14, 2022. In 2018, KeyBank issued the following notes under the 2015 Global Bank Note Program: on March 7, 2018, $500 million of 3.375% Senior Bank Notes due March 7, 2023; and on June 13, 2018, $500 million of 3.35% Senior Bank Notes due June 15, 2021. On September 28, 2018, KeyBank again updated its Bank Note Program authorizing the issuance of up to $20 billion of notes. Under the program, KeyBank is authorized to issue notes with original maturities of seven days or more for senior notes or five years or more for subordinated notes. Notes will be denominated in U.S. dollars. Amounts outstanding under the program and any prior bank note programs are classified as “long-term debt” on the balance sheet. As of December 31, 2018, no notes had been issued under the 2018 Bank Note Program, and $20 billion remained available for issuance. KeyCorp shelf registration, including Medium-Term Note Program . KeyCorp has a shelf registration statement on file with the SEC under rules that allow companies to register various types of debt and equity securities without limitations on the aggregate amounts available for issuance. KeyCorp also maintains a Medium-Term Note Program that permits KeyCorp to issue notes with original maturities of nine months or more. In 2018, KeyCorp issued the following notes under the program: on April 30, 2018, $750 million of 4.10% Senior Notes due April 30, 2028; and on October 29, 2018, $500 million of 4.150% Senior Notes due October 29, 2025. At December 31, 2018 , KeyCorp had authorized and available for issuance up to $2.75 billion of additional debt securities under the Medium-Term Note Program.

Trust Preferred Securities Issu

Trust Preferred Securities Issued by Unconsolidated Subsidiaries	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Trust Preferred Securities Issued by Unconsolidated Subsidiaries	20. Trust Preferred Securities Issued by Unconsolidated Subsidiaries We own the outstanding common stock of business trusts formed by us that issued corporation-obligated mandatorily redeemable trust preferred securities. The trusts used the proceeds from the issuance of their trust preferred securities and common stock to buy debentures issued by KeyCorp. These debentures are the trusts’ only assets; the interest payments from the debentures finance the distributions paid on the mandatorily redeemable trust preferred securities. The outstanding common stock of these business trusts is recorded in “other investments” on our balance sheet. We unconditionally guarantee the following payments or distributions on behalf of the trusts: • required distributions on the trust preferred securities; • the redemption price when a capital security is redeemed; and • the amounts due if a trust is liquidated or terminated. The Regulatory Capital Rules require us to treat our mandatorily redeemable trust preferred securities as Tier 2 capital. The trust preferred securities, common stock, and related debentures are summarized as follows: dollars in millions Trust Preferred Securities, Net of Discount (a) Common Stock Principal Amount of Debentures, Net of Discount (b) Interest Rate of Trust Preferred Securities and (c) Maturity of Trust Preferred Securities and Debentures December 31, 2018 KeyCorp Capital I $ 156 $ 6 $ 162 3.136 % 2028 KeyCorp Capital II 100 4 104 6.875 2029 KeyCorp Capital III 131 4 135 7.750 2029 HNC Statutory Trust III 19 1 20 4.053 2035 Willow Grove Statutory Trust I 18 1 19 4.098 2036 HNC Statutory Trust IV 16 1 17 3.800 2037 Westbank Capital Trust II 7 — 7 4.982 2034 Westbank Capital Trust III 7 — 7 4.982 2034 Total $ 454 $ 17 $ 471 5.447 % — December 31, 2017 $ 463 $ 17 $ 480 4.977 % — (a) The trust preferred securities must be redeemed when the related debentures mature, or earlier if provided in the governing indenture. Each issue of trust preferred securities carries an interest rate identical to that of the related debenture. Certain trust preferred securities include basis adjustments related to fair value hedges totaling $46 million at December 31, 2018 , and $55 million at December 31, 2017 . See Note 8 (“Derivatives and Hedging Activities”) for an explanation of fair value hedges. (b) We have the right to redeem these debentures. If the debentures purchased by KeyCorp Capital I, HNC Statutory Trust III, Willow Grove Statutory Trust I, HNC Statutory Trust IV, Westbank Capital Trust II, or Westbank Capital Trust III are redeemed before they mature, the redemption price will be the principal amount, plus any accrued but unpaid interest. If the debentures purchased by KeyCorp Capital II or KeyCorp Capital III are redeemed before they mature, the redemption price will be the greater of: (i) the principal amount, plus any accrued but unpaid interest, or (ii) the sum of the present values of principal and interest payments discounted at the Treasury Rate (as defined in the applicable indenture), plus 20 basis points for KeyCorp Capital II or 25 basis points for KeyCorp Capital III or 50 basis points in the case of redemption upon either a tax or a capital treatment event for either KeyCorp Capital II or KeyCorp Capital III, plus any accrued but unpaid interest. The principal amount of certain debentures includes basis adjustments related to fair value hedges totaling $46 million at December 31, 2018 , and $55 million at December 31, 2017 . See Note 8 for an explanation of fair value hedges. The principal amount of debentures, net of discounts, is included in “long-term debt” on the balance sheet. (c) The interest rates for the trust preferred securities issued by KeyCorp Capital II and KeyCorp Capital III are fixed. The trust preferred securities issued by KeyCorp Capital I have a floating interest rate, equal to three-month LIBOR plus 74 basis points, that reprices quarterly. The trust preferred securities issued by HNC Statutory Trust III have a floating interest rate, equal to three-month LIBOR plus 140 basis points, that reprices quarterly. The trust preferred securities issued by Willow Grove Statutory Trust I have a floating interest rate, equal to three-month LIBOR plus 131 basis points, that reprices quarterly. The trust preferred securities issued by HNC Statutory Trust IV have a floating interest rate, equal to three-month LIBOR plus 128 basis points, that reprices quarterly. The trust preferred securities issued by Westbank Capital Trust II and Westbank Capital Trust III each have a floating interest rate, equal to three-month LIBOR plus 219

Commitments, Contingent Liabili

Commitments, Contingent Liabilities and Guarantees	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingent Liabilities and Guarantees	21. Commitments, Contingent Liabilities, and Guarantees Obligations under Noncancelable Leases We are obligated under various noncancelable operating leases for land, buildings and other property, consisting principally of data processing equipment. Rental expense under all operating leases totaled $149 million in 2018 , $153 million in 2017 , and $118 million in 2016 . Minimum future rental payments under noncancelable operating leases at December 31, 2018 , are as follows: 2019 — $142 million ; 2020 — $133 million ; 2021 — $118 million ; 2022 — $104 million ; 2023 — $90 million ; all subsequent years — $321 million . Commitments to Extend Credit or Funding Loan commitments provide for financing on predetermined terms as long as the client continues to meet specified criteria. These agreements generally carry variable rates of interest and have fixed expiration dates or termination clauses. We typically charge a fee for our loan commitments. Since a commitment may expire without resulting in a loan, our aggregate outstanding commitments may significantly exceed our eventual cash outlay. Loan commitments involve credit risk not reflected on our balance sheet. We mitigate exposure to credit risk with internal controls that guide how we review and approve applications for credit, establish credit limits and, when necessary, demand collateral. In particular, we evaluate the creditworthiness of each prospective borrower on a case-by-case basis and, when appropriate, adjust the allowance for credit losses on lending-related commitments. Additional information pertaining to this allowance is included in Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Liability for Credit Losses on Lending-Related Commitments,” and in Note 5 (“ Asset Quality ”). We also provide financial support to private equity investments, including existing direct portfolio companies and indirect private equity funds, to satisfy unfunded commitments. These unfunded commitments are not recorded on our balance sheet. Additional information on principal investing commitments is provided in Note 6 (“ Fair Value Measurements ”). Other unfunded equity investment commitments at December 31, 2018 , and December 31, 2017 , related to tax credit investments and were primarily attributable to LIHTC investments. Unfunded tax credit investment commitments are recorded on our balance sheet in “other liabilities.” Additional information on LIHTC commitments is provided in Note 12 (“ Variable Interest Entities ”). The following table shows the remaining contractual amount of each class of commitment related to extending credit or funding principal investments as of December 31, 2018 , and December 31, 2017 . For loan commitments and commercial letters of credit, this amount represents our maximum possible accounting loss on the unused commitment if the borrower were to draw upon the full amount of the commitment and subsequently default on payment for the total amount of the then outstanding loan. December 31, in millions 2018 2017 Loan commitments: Commercial and other $ 42,653 $ 40,315 Commercial real estate and construction 2,691 2,774 Home equity 9,982 9,673 Credit cards 6,152 5,890 Total loan commitments 61,478 58,652 Commercial letters of credit 86 231 Purchase card commitments 621 425 Principal investing commitments 26 29 Tax credit investment commitments 520 481 Securities underwriting — 9 Total loan and other commitments $ 62,731 $ 59,827 Legal Proceedings Litigation. From time to time, in the ordinary course of business, we and our subsidiaries are subject to various litigation, investigations, and administrative proceedings. Private, civil litigations may range from individual actions involving a single plaintiff to putative class action lawsuits with potentially thousands of class members. Investigations may involve both formal and informal proceedings, by both government agencies and self-regulatory bodies. These matters may involve claims for substantial monetary relief. At times, these matters may present novel claims or legal theories. Due to the complex nature of these various other matters, it may be years before some matters are resolved. While it is impossible to ascertain the ultimate resolution or range of financial liability, based on information presently known to us, we do not believe there is any matter to which we are a party, or involving any of our properties that, individually or in the aggregate, would reasonably be expected to have a material adverse effect on our financial condition. We continually monitor and reassess the potential materiality of these litigation matters. We note, however, that in light of the inherent uncertainty in legal proceedings there can be no assurance that the ultimate resolution will not exceed established reserves. As a result, the outcome of a particular matter, or a combination of matters, may be material to our results of operations for a particular period, depending upon the size of the loss or our income for that particular period. Guarantees We are a guarantor in various agreements with third parties. The following table shows the types of guarantees that we had outstanding at December 31, 2018 . Information pertaining to the basis for determining the liabilities recorded in connection with these guarantees is included in Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Guarantees.” December 31, 2018 Maximum Potential Undiscounted Future Payments Liability Recorded in millions Financial guarantees: Standby letters of credit $ 3,137 $ 72 Recourse agreement with FNMA 4,082 6 Residential mortgage reserve 1,549 6 Return guarantee agreement with LIHTC investors 2 2 Written put options (a) 2,345 88 Total $ 11,115 $ 174 (a) The maximum potential undiscounted future payments represent notional amounts of derivatives qualifying as guarantees. We determine the payment/performance risk associated with each type of guarantee described below based on the probability that we could be required to make the maximum potential undiscounted future payments shown in the preceding table. We use a scale of low ( 0% to 30% probability of payment), moderate (greater than 30% to 70% probability of payment), or high (greater than 70% probability of payment) to assess the payment/performance risk, and have determined that the payment/performance risk associated with each type of guarantee outstanding at December 31, 2018 , is low. Standby letters of credit. KeyBank issues standby letters of credit to address clients’ financing needs. These instruments obligate us to pay a specified third party when a client fails to repay an outstanding loan or debt instrument or fails to perform some contractual nonfinancial obligation. Any amounts drawn under standby letters of credit are treated as loans to the client; they bear interest (generally at variable rates) and pose the same credit risk to us as a loan. At December 31, 2018 , our standby letters of credit had a remaining weighted-average life of 2 years , with remaining actual lives ranging from less than 1 year to as many as 16 years . Recourse agreement with FNMA. We participate as a lender in the FNMA Delegated Underwriting and Servicing program. FNMA delegates responsibility for originating, underwriting, and servicing mortgages, and we assume a limited portion of the risk of loss during the remaining term on each commercial mortgage loan that we sell to FNMA. We maintain a reserve for such potential losses in an amount that we believe approximates the fair value of our liability. At December 31, 2018 , the outstanding commercial mortgage loans in this program had a weighted-average remaining term of 7.9 years , and the unpaid principal balance outstanding of loans sold by us as a participant was $14.1 billion . The maximum potential amount of undiscounted future payments that we could be required to make under this program, as shown in the preceding table, is equal to approximately 29% of the principal balance of loans outstanding at December 31, 2018 . If we are required to make a payment, we would have an interest in the collateral underlying the related commercial mortgage loan; any loss we incur could be offset by the amount of any recovery from the collateral. Residential Mortgage Banking. We often originate and sell residential mortgage loans and retain the servicing rights. Our loan sales activity is generally conducted through loan sales in a secondary market sponsored by FNMA and FHLMC. Subsequent to the sale of mortgage loans, we do not typically retain any interest in the underlying loans except through our relationship as the servicer of the loans. As is customary in the mortgage banking industry, we, or banks we have acquired, have made certain representations and warranties related to the sale of residential mortgage loans (including loans sold with servicing rights released) and to the performance of our obligations as servicer. The breach of any such representations or warranties could result in losses for us. Our maximum exposure to loss is equal to the outstanding principal balance of the sold loans; however, any loss would be reduced by any payments received on the loans or through the sale of collateral. At December 31, 2018 , the outstanding residential mortgage loans in this program had an original weighted-average loan to value ratio of 74% , and the unpaid principal balance outstanding of loans sold by us was $5.2 billion . The risk assessment is low for the residential mortgage product. The maximum potential amount of undiscounted future payments that we could be required to make under this program, as shown in the preceding table, is equal to approximately 30% of the principal balance of loans outstanding at December 31, 2018 . Our liability for estimated repurchase obligations on loans sold, which is included in other liabilities on our balance sheet, was $6 million at December 31, 2018 . Return guarantee agreement with LIHTC investors. KAHC, a subsidiary of KeyBank, offered limited partnership interests to qualified investors. Partnerships formed by KAHC invested in low-income residential rental properties that qualify for federal low-income housing tax credits under Section 42 of the Internal Revenue Code. In certain partnerships, investors paid a fee to KAHC for a guaranteed return that is based on the financial performance of the property and the property’s confirmed LIHTC status throughout a 15 -year compliance period. Typically, KAHC fulfills these guaranteed returns by distributing tax credits and deductions associated with the specific properties. If KAHC defaults on its obligation to provide the guaranteed return, KeyBank is obligated to make any necessary payments to investors. No recourse or collateral is available to offset our guarantee obligation other than the underlying income streams from the properties and the residual value of the operating partnership interests. As shown in the previous table, KAHC maintained a reserve in the amount of $2 million at December 31, 2018 , which is sufficient to cover estimated future obligations under the guarantees. The maximum exposure to loss reflected in the table represents undiscounted future payments due to investors for the return on and of their investments. These guarantees have expiration dates that extend through 2018, but KAHC has not formed any new partnerships under this program since October 2003. Additional information regarding these partnerships is included in Note 12 (“ Variable Interest Entities ”). Written put options. In the ordinary course of business, we “write” put options for clients that wish to mitigate their exposure to changes in interest rates and commodity prices. At December 31, 2018 , our written put options had an average life of 3 years . These instruments are considered to be guarantees, as we are required to make payments to the counterparty (the client) based on changes in an underlying variable that is related to an asset, a liability, or an equity security that the client holds. We are obligated to pay the client if the applicable benchmark interest rate or commodity price is above or below a specified level (known as the “strike rate”). These written put options are accounted for as derivatives at fair value, as further discussed in Note 8 (“ Derivatives and Hedging Activities ”). We mitigate our potential future payment obligations by entering into offsetting positions with third parties. Written put options where the counterparty is a broker-dealer or bank are accounted for as derivatives at fair value but are not considered guarantees since these counterparties typically do not hold the underlying instruments. In addition, we are a purchaser and seller of credit derivatives, which are further discussed in Note 8 . Default guarantees. Some lines of business participate in guarantees that obligate us to perform if the debtor (typically a client) fails to satisfy all of its payment obligations to third parties. We generally undertake these guarantees for one of two possible reasons: (i) either the risk profile of the debtor should provide an investment return, or (ii) we are supporting our underlying investment in the debtor. We do not hold collateral for the default guarantees. If we were required to make a payment under a guarantee, we would receive a pro rata share should the third party collect some or all of the amounts due from the debtor. At December 31, 2018 , we had less than $1 million default guarantees. Other Off-Balance Sheet Risk Other off-balance sheet risk stems from financial instruments that do not meet the definition of a guarantee as specified in the applicable accounting guidance, and from other relationships. Indemnifications provided in the ordinary course of business. We provide certain indemnifications, primarily through representations and warranties in contracts that we execute in the ordinary course of business in connection with loan and lease sales and other ongoing activities, as well as in connection with purchases and sales of businesses. We maintain reserves, when appropriate, with respect to liability that reasonably could arise as a result of these indemnities. Intercompany guarantees.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income	22. Accumulated Other Comprehensive Income Our changes in AOCI for the years ended December 31, 2018 , and December 31, 2017 , are as follows: in millions Unrealized gains (losses) on securities available for sale Unrealized gains (losses) on derivative financial instruments Foreign currency translation adjustment Net pension and postretirement benefit costs Total Balance at December 31, 2016 $ (185 ) $ (14 ) $ (3 ) $ (339 ) $ (541 ) Other comprehensive income before reclassification, net of income taxes (69 ) (48 ) 12 9 (96 ) Amounts reclassified from accumulated other comprehensive income, net of income taxes (a) (1 ) (10 ) 1 9 (1 ) Amounts reclassified from accumulated other comprehensive income resulting from new federal corporate income tax rate (b) (56 ) (14 ) (1 ) (70 ) (141 ) Net current-period other comprehensive income, net of income taxes (126 ) (72 ) 12 (52 ) (238 ) Balance at December 31, 2017 $ (311 ) $ (86 ) $ 9 $ (391 ) $ (779 ) Other comprehensive income before reclassification, net of income taxes (62 ) 7 (10 ) (15 ) (80 ) Amounts reclassified from accumulated other comprehensive income, net of income taxes (a) — 29 — 25 54 Other amounts reclassified from AOCI, net of income taxes — — (13 ) — (13 ) Net current-period other comprehensive income, net of income taxes (62 ) 36 (23 ) 10 (39 ) Balance at December 31, 2018 $ (373 ) $ (50 ) $ (14 ) $ (381 ) $ (818 ) (a) See table below for details about these reclassifications. (b) See Note 13, Income Taxes, for details about the accounting impacts resulting from the TCJ Act. Our reclassifications out of AOCI for the years ended December 31, 2018 , and December 31, 2017 , are as follows: Twelve months ended December 31, Affected Line Item in the Statement Where Net Income is Presented in millions 2018 2017 Unrealized gains (losses) on available for sale securities Realized gains — $ 1 Other income Realized losses — — Other income — 1 Income (loss) from continuing operations before income taxes — — Income taxes — $ 1 Income (loss) from continuing operations Unrealized gains (losses) on derivative financial instruments Interest rate $ (68 ) $ 19 Interest income — Loans Interest rate (2 ) (4 ) Interest expense — Long-term debt Interest rate 2 — Investment banking and debt placement fees Foreign exchange contracts 31 — Other income (37 ) 15 Income (loss) from continuing operations before income taxes (8 ) 5 Income taxes $ (29 ) $ 10 Income (loss) from continuing operations Foreign currency translation adjustment — $ (1 ) Corporate services income — (1 ) Income (loss) from continuing operations before income taxes — — Income taxes — $ (1 ) Income (loss) from continuing operations Net pension and postretirement benefit costs Amortization of losses $ (17 ) $ (15 ) Personnel expense Settlement loss (17 ) — Personnel expense Amortization of prior service credit 1 1 Personnel expense (33 ) (14 ) Income (loss) from continuing operations before income taxes (8 ) (5 ) Income taxes $ (25 ) $ (9 ) Income (loss) from continuing operations

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Shareholders' Equity	23. Shareholders' Equity Comprehensive Capital Plan As previously reported and as authorized by the Board and pursuant to our 2018 capital plan (which is effective through the second quarter of 2019 ) submitted to and not objected to by the Federal Reserve, we have authority to repurchase up to $1.225 billion of our Common Shares. During 2018 , we repurchased $325 million of Common Shares under our 2017 capital plan authorization and $820 million under our 2018 capital plan authorization. Consistent with our 2017 capital plan, the Board declared a quarterly dividend of $.105 per Common Share for the first quarter of 2018 , and $.12 per Common Share for the second quarter of 2018 . The Board declared a quarterly dividend of $.17 per Common Share for the third and fourth quarters of 2018 , consistent with our 2018 capital plan. These quarterly dividend payments brought our annual dividend to $.565 per Common Share for 2018 . Preferred Stock The following table summarizes our preferred stock at December 31, 2018 : Preferred stock series Amount outstanding (in millions) Shares authorized and outstanding Par value Liquidation preference Ownership interest per depositary share Liquidation preference per depositary share 2018 dividends paid per depositary share Fixed-to-Floating Rate Perpetual Noncumulative Series D $ 525 21,000 $ 1 $ 25,000 1/25th $ 1,000 $ 50.00 Fixed-to-Floating Rate Perpetual Noncumulative Series E 500 500,000 1 1,000 1/40th 25 1.531252 Fixed Rate Perpetual Noncumulative Series F 425 425,000 1 1,000 1/40th 25 .529688 Capital Adequacy KeyCorp and KeyBank (consolidated) must meet specific capital requirements imposed by federal banking regulators. Sanctions for failure to meet applicable capital requirements may include regulatory enforcement actions that restrict dividend payments, require the adoption of remedial measures to increase capital, terminate FDIC deposit insurance, and mandate the appointment of a conservator or receiver in severe cases. In addition, failure to maintain a “well capitalized” status affects how regulators evaluate applications for certain endeavors, including acquisitions, continuation and expansion of existing activities, and commencement of new activities, and could make clients and potential investors less confident. As of December 31, 2018 , KeyCorp and KeyBank (consolidated) met all regulatory capital requirements. KeyBank (consolidated) qualified for the “well capitalized” prompt corrective action capital category at December 31, 2018 , because its capital and leverage ratios exceeded the prescribed threshold ratios for that capital category and it was not subject to any written agreement, order, or directive to meet and maintain a specific capital level for any capital measure. Since that date, we believe there has been no change in condition or event that has occurred that would cause the capital category for KeyBank (consolidated) to change. BHCs are not assigned to any of the five prompt corrective action capital categories applicable to insured depository institutions. If, however, those categories applied to BHCs, we believe that KeyCorp would satisfy the criteria for a “well capitalized” institution at December 31, 2018 , and since that date, we believe there has been no change in condition or event that has occurred that would cause such capital category to change. Because the regulatory capital categories under the prompt corrective action regulations serve a limited supervisory function, investors should not use them as a representation of the overall financial condition or prospects of KeyBank or KeyCorp. At December 31, 2018 , Key and KeyBank (consolidated) had regulatory capital in excess of all current minimum risk-based capital (including all adjustments for market risk) and leverage ratio requirements as shown in the following table. Actual To Meet Minimum Capital Adequacy Requirements To Qualify as Well Capitalized Under Federal Deposit Insurance Act dollars in millions Amount Ratio Amount Ratio Amount Ratio December 31, 2018 TOTAL CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 15,953 12.89 % $ 9,903 8.00 % N/A N/A KeyBank (consolidated) 15,432 12.68 9,733 8.00 $ 12,166 10.00 % TIER 1 CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 13,712 11.08 % $ 7,427 6.00 % N/A N/A KeyBank (consolidated) 13,575 11.16 7,300 6.00 $ 7,300 6.00 % TIER 1 CAPITAL TO AVERAGE QUARTERLY TANGIBLE ASSETS Key $ 13,712 9.89 % $ 5,548 4.00 % N/A N/A KeyBank (consolidated) 13,575 9.93 5,470 4.00 $ 6,838 5.00 % December 31, 2017 TOTAL CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 15,345 12.92 % $ 9,505 8.00 % N/A N/A KeyBank (consolidated) 14,957 12.86 9,306 8.00 $ 11,633 10.00 % TIER 1 CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 13,083 11.01 % $ 7,129 6.00 % N/A N/A KeyBank (consolidated) 13,110 11.27 6,980 6.00 $ 6,980 6.00 % TIER 1 CAPITAL TO AVERAGE QUARTERLY TANGIBLE ASSETS Key $ 13,083 9.73 % $ 5,379 4.00 % N/A N/A KeyBank (consolidated) 13,110 9.91 5,293 4.00 $ 6,617 5.00 %

Line of Business Results

Line of Business Results	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Line of Business Results	24. Line of Business Results The specific lines of business that constitute each of the major business segments (operating segments) are described below. Key Community Bank Key Community Bank serves individuals and small to mid-sized businesses through its 15 -state branch network. Individuals are provided branch-based deposit and investment products, personal finance services, and loans, including residential mortgages, home equity, credit card, and various types of installment loans. Key Community Bank also purchases retail auto sales contracts via a network of auto dealerships. The auto dealerships finance the sale of automobiles as the initial lender and then assign the contracts to us pursuant to dealer agreements. In addition, financial, estate and retirement planning, asset management services, and Delaware Trust capabilities are offered to assist high-net-worth clients with their banking, trust, portfolio management, life insurance, charitable giving, and related needs. Small businesses are provided deposit, investment and credit products, and business advisory services. Mid-sized businesses are provided products and services, some of which are delivered by Key Corporate Bank, that include commercial lending, cash management, equipment leasing, investment, and employee benefit programs, succession planning, access to capital markets, derivatives, and foreign exchange. Key Corporate Bank Key Corporate Bank is a full-service corporate and investment bank focused principally on serving the needs of middle market clients in seven industry sectors: consumer, energy, healthcare, industrial, public sector, real estate, and technology. Key Corporate Bank delivers a broad suite of banking and capital markets products to its clients, including syndicated finance, debt and equity capital markets, commercial payments, equipment finance, commercial mortgage banking, derivatives, foreign exchange, financial advisory, and public finance. Key Corporate Bank is also a significant servicer of commercial mortgage loans and a significant special servicer of CMBS. Key Corporate Bank delivers many of its product capabilities to clients of Key Community Bank. Other Segments Other Segments consists of Corporate Treasury, Principal Investing, and various exit portfolios. Reconciling Items Total assets included under “Reconciling Items” primarily represent the unallocated portion of nonearning assets of corporate support functions. Reconciling Items also includes intercompany eliminations and certain items that are not allocated to the business segments because they do not reflect their normal operations, including merger-related charges and certain impacts of tax reform. The table on the following pages shows selected financial data for our major business segments for the years ended December 31, 2018 , 2017 , and 2016 . The information was derived from the internal financial reporting system that we use to monitor and manage our financial performance. GAAP guides financial accounting, but there is no authoritative guidance for “management accounting” — the way we use our judgment and experience to make reporting decisions. Consequently, the line of business results we report may not be comparable to line of business results presented by other companies. The selected financial data is based on internal accounting policies designed to compile results on a consistent basis and in a manner that reflects the underlying economics of the businesses. In accordance with our policies: • Net interest income is determined by assigning a standard cost for funds used or a standard credit for funds provided based on their assumed maturity, prepayment, and/or repricing characteristics. • Indirect expenses, such as computer servicing costs and corporate overhead, are allocated based on assumptions regarding the extent that each line of business actually uses the services. • The consolidated provision for credit losses is allocated among the lines of business primarily based on their actual net loan charge-offs, adjusted periodically for loan growth and changes in risk profile. The amount of the consolidated provision is based on the methodology that we use to estimate our consolidated ALLL. This methodology is described in Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Allowance for Loan and Lease Losses. • Income taxes are allocated based on the 2018 statutory federal income tax rate of 21% and a blended state income tax rate (net of the federal income tax benefit) of 2.7% . Prior to 2018, income taxes were allocated based on the previous statutory federal income tax rate of 35% and a blended state income tax rate (net of the federal income tax benefit) of 2.2% . • Capital is assigned to each line of business based on economic equity. Developing and applying the methodologies that we use to allocate items among our lines of business is a dynamic process. Accordingly, financial results may be revised periodically to reflect enhanced alignment of expense base allocation drivers, changes in the risk profile of a particular business, or changes in our organizational structure. Year ended December 31, Key Community Bank Key Corporate Bank dollars in millions 2018 2017 2016 2018 2017 2016 SUMMARY OF OPERATIONS Net interest income (TE) $ 2,873 $ 2,652 $ 1,953 $ 1,094 $ 1,193 $ 1,049 Noninterest income 1,098 1,143 906 1,161 1,148 1,013 Total revenue (TE) (a) 3,971 3,795 2,859 2,255 2,341 2,062 Provision for credit losses 177 209 143 74 20 127 Depreciation and amortization expense 110 116 76 135 96 60 Other noninterest expense 2,451 2,424 2,048 1,147 1,158 1,073 Income (loss) from continuing operations before income taxes (TE) 1,233 1,046 592 899 1,067 802 Allocated income taxes (benefit) and TE adjustments 291 388 220 110 249 178 Income (loss) from continuing operations 942 658 372 789 818 624 Income (loss) from discontinued operations, net of taxes — — — — — — Net income (loss) 942 658 372 789 818 624 Less: Net income (loss) attributable to noncontrolling interests — — — — — (2 ) Net income (loss) attributable to Key $ 942 $ 658 $ 372 $ 789 $ 818 $ 626 AVERAGE BALANCES (b) Loans and leases $ 47,877 $ 47,399 $ 37,624 $ 39,536 $ 37,716 $ 31,925 Total assets (a) 51,774 51,370 40,300 47,126 44,505 37,797 Deposits 81,868 79,669 63,875 21,183 21,318 20,780 OTHER FINANCIAL DATA Expenditures for additions to long-lived assets (a), (b) $ 2,352 $ 2,438 $ 1,478 $ 538 $ 559 $ 340 Net loan charge-offs (b) 161 166 114 73 40 83 Return on average allocated equity (b) 19.50 % 13.71 % 10.96 % 27.01 % 28.82 % 26.89 % Return on average allocated equity 19.50 13.71 10.96 27.01 28.82 26.89 Average full-time equivalent employees (c) 10,501 10,587 8,794 2,528 2,407 2,244 (a) Substantially all revenue generated by our major business segments is derived from clients that reside in the United States. Substantially all long-lived assets, including premises and equipment, capitalized software, and goodwill held by our major business segments, are located in the United States. (b) From continuing operations. (c) The number of average full-time equivalent employees was not adjusted for discontinued operations. Other Segments Total Segments Reconciling Items Key 2018 2017 2016 2018 2017 2016 2018 2017 2016 2018 2017 2016 $ (55 ) $ (35 ) $ (45 ) $ 3,912 $ 3,810 $ 2,957 $ 28 $ 20 $ (4 ) $ 3,940 $ 3,830 $ 2,953 206 208 170 2,465 2,499 2,089 50 (21 ) (18 ) 2,515 2,478 2,071 151 173 125 6,377 6,309 5,046 78 (1 ) (22 ) 6,455 6,308 5,024 (5 ) — (4 ) 246 229 266 — — — 246 229 266 1 3 4 246 215 140 154 169 163 400 384 303 53 101 61 3,651 3,683 3,182 (76 ) 31 271 3,575 3,714 3,453 102 69 64 2,234 2,182 1,458 — (201 ) (456 ) 2,234 1,981 1,002 (8 ) (48 ) (22 ) 393 589 376 (18 ) 101 (163 ) 375 690 213 110 117 86 1,841 1,593 1,082 18 (302 ) (293 ) 1,859 1,291 789 — — — — — — 7 7 1 7 7 1 110 117 86 1,841 1,593 1,082 25 (295 ) (292 ) 1,866 1,298 790 — 3 2 — 3 — — (1 ) (1 ) — 2 (1 ) $ 110 $ 114 $ 84 $ 1,841 $ 1,590 $ 1,082 $ 25 $ (294 ) $ (291 ) $ 1,866 $ 1,296 $ 791 $ 916 $ 1,225 $ 1,486 $ 88,329 $ 86,340 $ 71,035 $ 9 $ 25 $ 113 $ 88,338 $ 86,365 $ 71,148 37,551 37,158 31,938 136,451 133,033 110,035 361 686 2,502 136,812 133,719 112,537 1,956 1,988 1,213 105,007 102,975 85,868 44 (29 ) 484 105,051 102,946 86,352 $ 10 19 — $ 2,900 $ 3,016 $ 1,818 $ 101 $ 81 $ 116 $ 3,001 $ 3,097 $ 1,934 (1 ) $ 1 $ 7 233 207 204 1 1 1 234 208 205 88.00 % 73.55 % 48.84 % 23.37 % 20.41 % 18.36 % .25 % (4.05 )% (4.32 )% 12.29 % 8.47 % 6.25 % 88.00 73.55 48.84 23.37 20.41 18.36 .34 (3.96 ) (4.31 ) 12.33 8.51 6.25 130 338 147 13,159 13,332 11,185 5,021 5,083 4,515 18,180 18,415 15,700

Condensed Financial Information

Condensed Financial Information of the Parent Company	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Financial Information of the Parent Company	25. Condensed Financial Information of the Parent Company CONDENSED BALANCE SHEETS December 31, in millions 2018 2017 ASSETS Cash and due from banks $ 3,241 $ 2,257 Short-term investments 19 22 Securities available for sale 10 10 Other investments 31 29 Loans to: Banks 50 250 Nonbank subsidiaries 31 31 Total loans 81 281 Investment in subsidiaries: Banks 15,554 15,169 Nonbank subsidiaries 833 885 Total investment in subsidiaries 16,387 16,054 Goodwill 167 167 Corporate-owned life insurance 199 208 Derivative assets 61 29 Accrued income and other assets 279 353 Total assets $ 20,475 $ 19,410 LIABILITIES Accrued expense and other liabilities $ 480 $ 466 Long-term debt due to: Subsidiaries 471 480 Unaffiliated companies 3,929 3,441 Total long-term debt 4,400 3,921 Total liabilities 4,880 4,387 SHAREHOLDERS’ EQUITY (a) 15,595 15,023 Total liabilities and shareholders’ equity $ 20,475 $ 19,410 (a) See Key’s Consolidated Statements of Changes in Equity. CONDENSED STATEMENTS OF INCOME Year ended December 31, in millions 2018 2017 2016 INCOME Dividends from subsidiaries: Bank subsidiaries $ 1,675 $ 750 $ 625 Nonbank subsidiaries — — 50 Interest income from subsidiaries 11 10 10 Other income 11 9 11 Total income 1,697 769 696 EXPENSE Interest on long-term debt with subsidiary trusts 20 17 14 Interest on other borrowed funds 137 95 69 Personnel and other expense 69 46 101 Total expense 226 158 184 Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries 1,471 611 512 Income tax (expense) benefit 55 29 54 Income (loss) before equity in net income (loss) less dividends from subsidiaries 1,526 640 566 Equity in net income (loss) less dividends from subsidiaries 340 658 224 NET INCOME (LOSS) 1,866 1,298 790 Less: Net income attributable to noncontrolling interests — 2 (1 ) NET INCOME (LOSS) ATTRIBUTABLE TO KEY $ 1,866 $ 1,296 $ 791 . CONDENSED STATEMENTS OF CASH FLOWS Year ended December 31, in millions 2018 2017 2016 OPERATING ACTIVITIES Net income (loss) attributable to Key $ 1,866 $ 1,296 $ 791 Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities: Deferred income taxes (benefit) 109 38 (24 ) Stock-based compensation expense 8 11 12 Equity in net (income) loss less dividends from subsidiaries (340 ) (658 ) (224 ) Other intangible asset amortization — — — Net (increase) decrease in goodwill and other intangibles — — — Net (increase) decrease in other assets (58 ) 82 (93 ) Net increase (decrease) in other liabilities 8 (82 ) 9 Other operating activities, net 79 (114 ) — NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES 1,672 573 471 INVESTING ACTIVITIES Net (increase) decrease in securities available for sale and in short-term and other investments 1 47 (17 ) Cash infusion from purchase of Cain Brothers — (90 ) — Cash used in acquisitions — — (481 ) Proceeds from sales, prepayments and maturities of securities available for sale — 1 — Net (increase) decrease in loans to subsidiaries 200 — 160 NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES 201 (42 ) (338 ) FINANCING ACTIVITIES Net proceeds from issuance of long-term debt 1,250 — — Payments on long-term debt (750 ) — (21 ) Repurchase of Treasury Shares (1,145 ) (730 ) (140 ) Net cash from the issuance (redemption) of Common Shares and preferred stock 412 (350 ) 1,041 Cash dividends paid (656 ) (480 ) (335 ) NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES (889 ) (1,560 ) 545 NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS 984 (1,029 ) 678 CASH AND DUE FROM BANKS AT BEGINNING OF YEAR 2,257 3,286 2,608 CASH AND DUE FROM BANKS AT END OF YEAR $ 3,241 $ 2,257 $ 3,286 KeyCorp paid interest on borrowed funds totaling $131 million in 2018 , $120 million in 2017 , and $114 million in 2016

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	26. Revenue from Contracts with Customers The following table represents a disaggregation of revenue from contracts with customers, by line of business, for the twelve months ended December 31, 2018 : Twelve months ended December 31, 2018 dollars in millions Key Community Bank Key Corporate Bank Total Contract Revenue NONINTEREST INCOME Trust and investment services income $ 358 $ 69 $ 427 Investment banking and debt placement fees 5 255 260 Services charges on deposit accounts 310 52 362 Cards and payments income 155 108 263 Other noninterest income 18 — 18 Total revenue from contracts with customers $ 846 $ 484 $ 1,330 Other noninterest income (a) $ 929 Noninterest income from other segments (b) 206 Reconciling items (c) 50 Total noninterest income $ 2,515 (a) Noninterest income considered earned outside the scope of contracts with customers. (b) Other Segments consist of corporate treasury, our principal investing unit, and various exit portfolios. (c) Reconciling items consist primarily of the gain on the sale of, and contract revenue recognized prior to the sale of, KIBS for the second quarter of 2018, intercompany eliminations, and items not allocated to the business segments because they do not reflect their normal operations. Refer to Note 24 (“Line of Business Results”) for more information. We have no material contract assets or contract liabilities for the twelve months ended December 31, 2018

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates
Principles of Consolidation and Basis of Presentation	Principles of Consolidation and Basis of Presentation The consolidated financial statements include the accounts of KeyCorp and its subsidiaries. All significant intercompany accounts and transactions have been eliminated in consolidation. Some previously reported amounts have been reclassified to conform to current reporting practices. The consolidated financial statements also include the accounts of any voting rights entities in which we have a controlling financial interest and certain VIEs. In accordance with the applicable accounting guidance for consolidations, we consolidate a VIE if we have the power to direct activities of the VIE that most significantly impact the entity’s economic performance; and the obligation to absorb losses of the entity or the right to receive benefits from the entity that could potentially be significant to the VIE. See Note 12 (“ Variable Interest Entities ”) for information on our involvement with VIEs. We use the equity method to account for unconsolidated investments in voting rights entities or VIEs if we have significant influence over the entity’s operating and financing decisions (usually defined as a voting or economic interest of 20% to 50% , but not controlling). Unconsolidated investments in voting rights entities or VIEs in which we have a voting or economic interest of less than 20% generally are carried at fair value or a cost measurement alternative.
Cash and Cash Equivalents	Cash and Cash Equivalents
Loans	Loans Loans held in portfolio, which management has the intent and ability to hold for the foreseeable future or until maturity or payoff, are carried at the principal amount outstanding, net of unearned income, including net deferred loan fees and costs and unamortized premiums and discounts. We defer certain nonrefundable loan origination and commitment fees, and the direct costs of originating or acquiring loans. The net deferred amount is amortized over the estimated lives of the related loans as an adjustment to the yield. Direct financing leases are carried at the aggregate of the lease receivable plus estimated unguaranteed residual values, less unearned income and deferred initial direct fees and costs. Unearned income on direct financing leases is amortized over the lease terms using a method approximating the interest method that produces a constant rate of return. Deferred initial direct fees and costs are amortized over the lease terms as an adjustment to the yield.
Loans Held for Sale	Loans Held for Sale Loans held for sale generally include certain residential and commercial mortgage loans and other commercial loans. Loans are initially classified as held for sale when they are individually identified as being available for immediate sale and a formal plan exists to sell them. Loans held for sale are recorded at either fair value, if elected, or the lower of cost or fair value. Fair value is determined based on available market data for similar assets. When a loan is originated as held-for-sale, we do not defer the related fees and costs. Our commercial loans (including commercial mortgage and non-mortgage loans), which we originated and intend to sell, are carried at the lower of aggregate cost or fair value. Subsequent declines in fair value for loans held for sale are recognized as a charge to “other income” on the income statement. Consumer real estate - residential mortgages loans have been elected to be carried at fair value. Subsequent increases and decreases in fair value for loans elected to be measured at fair value are recorded to “consumer mortgage income” on the income statement. Additional information regarding fair value measurements associated with our loans held for sale is provided in Note 6 (“ Fair Value Measurements ”). We may transfer certain loans to held for sale at the lower of cost or fair value. If a loan is transferred from the loan portfolio to the held-for-sale category, any write-down in the carrying amount of the loan at the date of transfer is recorded as a reduction in the ALLL. When a loan is transferred into the held for sale category, we stop amortizing the related deferred fees and costs. The remaining unamortized fees and costs are recognized as part of the cost basis of the loan at the time it is sold.
Nonperforming Loans	Nonperforming Loans Nonperforming loans are loans for which we do not accrue interest income, and include commercial and consumer loans and leases as well as current year TDRs and nonaccruing TDR loans from prior years. Nonperforming loans do not include loans held for sale or PCI loans. We generally classify commercial loans as nonperforming and stop accruing interest (i.e., designate the loan “nonaccrual”) when the borrower’s principal or interest payment is 90 days past due unless the loan is well-secured and in the process of collection. Commercial loans are also placed on nonaccrual status when payment is not past due but we have serious doubts about the borrower’s ability to comply with existing repayment terms. Once a loan is designated nonaccrual (and as a result assessed for impairment), the interest accrued but not collected is generally charged against the ALLL, and payments subsequently received are applied to principal. Commercial loans are typically charged off in full or charged down to the fair value of the underlying collateral when the borrower’s payment is 180 days past due. We classify consumer loans as nonperforming and stop accruing interest when the borrower’s payment is 120 days past due, unless the loan is well-secured and in the process of collection. Any second lien home equity loan with an associated first lien that is 120 days or more past due or in foreclosure, or for which the first mortgage delinquency timeframe is unknown, is reported as a nonperforming loan. Secured loans that are discharged through Chapter 7 bankruptcy and not formally re-affirmed are designated as nonperforming and TDRs. Our charge-off policy for most consumer loans takes effect when payments are 120 days past due. Home equity and residential mortgage loans generally are charged down to net realizable value when payment is 180 days past due. Credit card loans and similar unsecured products continue to accrue interest until the account is charged off at 180 days past due. Commercial and consumer loans may be returned to accrual status if we are reasonably assured that all contractually due principal and interest are collectible and the borrower has demonstrated a sustained period (generally six months
Impaired Loans	Impaired Loans A loan is considered to be impaired when, based on current information and events, it is probable that we will be unable to collect all amounts due (both principal and interest) according to the contractual terms of the loan agreement. All consumer TDRs, regardless of size, and all commercial TDRs and non-accrual commercial loans with an outstanding balance of $2.5 million or greater are individually evaluated for impairment and assigned a specific reserve. Commercial non-accrual loans of less than $2.5 million
Allowance for Loan and Lease Losses	Allowance for Loan and Lease Losses The ALLL represents our estimate of incurred credit losses inherent in the loan portfolio at the balance sheet date. We establish the amount of this allowance by analyzing the quality of the loan portfolio at least quarterly, and more often if deemed necessary. We segregate our loan portfolio between commercial and consumer loans and develop and document our methodology to determine the ALLL accordingly. We believe these portfolio segments represent the most appropriate level for determining our historical loss experience, as well as the level at which we monitor credit quality and risk characteristics of the portfolios. Commercial loans, which generally have larger individual balances, constitute a significant portion of our total loan portfolio. The consumer portfolio typically includes smaller-balance homogeneous loans. We estimate the appropriate level of our ALLL by applying expected loss rates to existing loans with similar risk characteristics. Expected loss rates for commercial loans are derived from a statistical analysis of our historical default and loss severity experience. The analysis utilizes probability of default and loss given default to assign loan grades using our internal risk rating system. Our expected loss rates are reviewed quarterly and updated as necessary. As of December 31, 2018 , the probability of default ratings was based on our default data for the period from January 2008 through October 2018, which encompasses the last downturn period as well as our more recent positive credit experience. We adjust expected loss rates based on calculated estimates of the average time period from initial loss indication to the initial loss recorded for an individual loan. Expected loss rates for consumer loans are statistically derived from an analysis of our historical default and loss severity experience, and is sensitive to change in delinquency status. Consumer loans are analyzed quarterly in homogeneous product-type pools that share similar risk attributes, including the application of delinquency roll rate models and credit loss severity estimates. Incurred losses that are not yet individually identifiable are measured as the estimate of the average time period for initial loss indication to initial loss recorded for consumer loans. The ALLL may be adjusted to reflect our current assessment of many qualitative factors that may not be directly measured in the statistical analysis of expected loss, including: • changes in international, national, regional, and local economic and business conditions; • changes in the experience, ability, and depth of our lending management and staff; • changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices; • changes in the nature and volume of the loan portfolio, including the existence and effect of any concentrations of credit, and changes in the level of such concentrations; • changes in the volume and/or severity of past due, nonaccrual, and adversely classified or graded loans; and • external factors, such as competition, legal developments, and regulatory requirements. For all consumer loan TDRs, regardless of size, as well as all commercial TDRs and non-accrual commercial loans with an outstanding balance of $2.5 million or greater, we conduct further analysis to determine the probable loss content and assign a specific allowance to the loan if deemed appropriate. We estimate the extent of the individual impairment for commercial loans and TDRs by comparing the recorded investment of the loan with the estimated present value of its future cash flows, the fair value of its underlying collateral, or the loan’s observable market
Liability for Credit Losses on Lending-Related Commitments	Liability for Credit Losses on Lending-Related CommitmentsThe liability for credit losses inherent in lending-related commitments, such as letters of credit and unfunded loan commitments, is included in “accrued expense and other liabilities” on the balance sheet and established through a charge to the provision for loan and lease losses. We determine the amount of this liability by considering both historical trends and current market conditions quarterly, or more often if deemed necessary.
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price to sell an asset or transfer a liability in an orderly transaction between market participants in the principal market. Therefore, fair value represents an exit price at the measurement date. We value our assets and liabilities based on the principal or most advantageous market where each would be sold (in the case of assets) or transferred (in the case of liabilities). In the absence of observable market transactions, we consider liquidity valuation adjustments to reflect the uncertainty in pricing the instruments. Valuation inputs can be observable or unobservable. Observable inputs are assumptions based on market data obtained from an independent source. Unobservable inputs are assumptions based on our own information or assessment of assumptions used by other market participants in pricing the asset or liability. Our unobservable inputs are based on the best and most current information available on the measurement date. All inputs, whether observable or unobservable, are ranked in accordance with a prescribed fair value hierarchy that gives the highest ranking to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest ranking to unobservable inputs (Level 3). Fair values for Level 2 assets and liabilities are based on one or a combination of the following factors: (i) quoted market prices for similar assets or liabilities; (ii) observable inputs, such as interest rates or yield curves; or (iii) inputs derived principally from or corroborated by observable market data. The level in the fair value hierarchy ascribed to a fair value measurement in its entirety is based on the lowest level input that is significant to the measurement. We consider an input to be significant if it drives 10% or more of the total fair value of a particular asset or liability. Assets and liabilities may transfer between levels based on the observable and unobservable inputs used at the valuation date, as the inputs may be influenced by certain market conditions. We recognize transfers between levels of the fair value hierarchy at the end of the reporting period.
Short-Term Investments	Short-Term InvestmentsShort-term investments consist of segregated, interest-bearing deposits due from banks, the Federal Reserve, and certain non-U.S. banks as well as reverse repurchase agreements.
Trading Account Assets	Trading Account Assets Trading account assets are debt and equity securities, as well as commercial loans, that we purchase and hold but intend to sell in the near term. These assets are reported at fair value. Realized and unrealized gains and losses on trading account assets are reported in “other income” on the income statement.
Securities	Securities Securities available for sale. Debt securities that we intend to hold for an indefinite period of time but that may be sold in response to changes in interest rates, prepayment risk, liquidity needs, or other factors are classified as available-for-sale and reported at fair value. Realized gains and losses resulting from sales of securities using the specific identification method, are included in “other income” on the income statement. Unrealized gains and losses (net of income taxes) deemed temporary are recorded in equity as a component of AOCI. Other-than-temporary unrealized losses on debt securities are included in “other income” on the income statement when the loss is attributable to credit. Other-than-temporary unrealized losses attributable to factors other than credit are recorded in AOCI. For additional information, refer to Note 7 (“ Securities ”). “Other securities” held in the available-for-sale portfolio consist of convertible preferred stock of privately held companies. Held-to-maturity securities. Debt securities that we have the intent and ability to hold until maturity are classified as held-to-maturity and are carried at cost and adjusted for amortization of premiums and accretion of discounts using the interest method. This method produces a constant rate of return on the adjusted carrying amount. “Other securities” held in the held-to-maturity portfolio consist of foreign bonds and capital securities. If any of the value of a held-to-maturity is determined to be unrecoverable, impairment will be recorded. Other Investments
Derivatives and Hedging	Derivatives and Hedging All derivatives are recognized on the balance sheet at fair value in “accrued income and other assets” or “accrued expense and other liabilities”. The net increase or decrease in derivatives is included in “other operating activities, net” within the statement of cash flows. Accounting for changes in fair value (i.e., gains or losses) of derivatives differs depending on whether the derivative has been designated and qualifies as part of a hedge relationship, and on the type of hedge relationship. For derivatives that are not in a hedge relationship, any gain or loss, as well as any premium paid or received, is recognized immediately in earnings in “corporate services income” or “other income” on the income statement, depending whether the derivative is for customer accommodation or risk management, respectively. A derivative that is designated and qualifies as a hedging instrument must be designated as a fair value hedge, a cash flow hedge, or a hedge of a net investment in a foreign operation. Changes in the fair value of a hedging instrument are reflected in the same income statement line as the earnings effect of the hedged item. A fair value hedge is used to limit exposure to changes in the fair value of existing assets, liabilities, and commitments caused by changes in interest rates or other economic factors. The change in the fair value of an instrument designated as a fair value hedge is recorded in earnings at the same time as a change in fair value of the hedged risk. A cash flow hedge is used to minimize the variability of future cash flows that is caused by changes in interest rates or other economic factors. The gain or loss on a cash flow hedge is recorded as a component of AOCI on the balance sheet and reclassified to earnings in the same period in which the hedged transaction affects earnings (e.g., when we incur variable-rate interest on debt, earn variable-rate interest on loans, or sell commercial real estate loans). A net investment hedge is used to hedge the exposure of changes in the carrying value of investments as a result of changes in the related foreign exchange rates. The gain or loss on a net investment hedge is recorded as a component of AOCI on the balance sheet when the terms of the derivative match the notional and currency risk being hedged. The amount in AOCI is reclassified into income when the hedged transaction affects earnings (e.g., when we dispose or liquidate a foreign subsidiary).
Offsetting Derivative Positions	We take into account the impact of bilateral collateral and master netting agreements that allow us to settle all derivative contracts held with a single counterparty on a net basis, and to offset the net derivative position with the related cash collateral when recognizing derivative assets and liabilities. As a result, we could have derivative contracts with negative fair values included in derivative assets on the balance sheet and contracts with positive fair values included in derivative liabilities. Derivative assets and derivative liabilities are recorded within “accrued income and other assets” and “accrued expense and other liabilities,” respectively.
Servicing Assets	Servicing Assets We service commercial real estate and residential mortgages loans. Servicing assets and liabilities purchased or retained are initially measured at fair value and are recorded as a component of “accrued income and other assets” on the balance sheet. When no ready market value (such as quoted market prices, or prices based on sales or purchases of similar assets) is available to determine the fair value of servicing assets, fair value is determined by calculating the present value of future cash flows associated with servicing the loans. This calculation is based on a number of assumptions, including the market cost of servicing, the discount rate, the prepayment rate, and the default rate. We account for our servicing assets using the amortization method. The amortization of servicing assets is determined in proportion to, and over the period of, the estimated net servicing income and recorded in “mortgage servicing fees” on the income statement.
Business Combinations	Business CombinationsWe account for our business combinations using the acquisition method of accounting. Under this accounting method, the acquired company’s assets and liabilities are recorded at fair value at the date of acquisition, except as provided for by the applicable accounting guidance, and the results of operations of the acquired company are combined with Key’s results from the date of acquisition forward. Acquisition costs are expensed when incurred. The difference between the purchase price and the fair value of the net assets acquired (including identifiable intangible assets) is recorded as goodwill. Our accounting policy for intangible assets is summarized in this note under the heading “Goodwill and Other Intangible Assets.”
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the amount by which the cost of net assets acquired in a business combination exceeds their f air value. Goodwill is assigned to reporting units as of the acquisition date based on the expected benefit to such reporting unit from the synergies of the business combination. Goodwill is not amortized. Goodwill is tested at the reporting unit level for impairment, at least annually as of October 1, or as events and circumstances change that would more-likely-than-not reduce the fair value of a reporting unit below its carrying amount. We may elect to perform a qualitative analysis to determine whether or not it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount. If we elect to bypass this qualitative analysis, or conclude via qualitative analysis that it is more-likely-than-not that the fair value of a reporting unit is less than its carrying value, a two-step goodwill impairment test is performed. In the first step, the fair value of each reporting unit is compared with its carrying value. If the fair value is greater than the carrying value, then the reporting unit's goodwill is deemed not to be impaired. If the fair value is less than the carrying value, then the second step is performed, which measures the amount of impairment by comparing the carrying amount of goodwill to its implied fair value. If the implied fair value of the goodwill exceeds the carrying amount, there is no impairment. If the carrying amount exceeds the implied fair value of the goodwill, an impairment charge is recorded for the excess. Other intangible assets with finite lives are amortized on either an accelerated or straight-line basis and are evaluated for impairment whenever events or circumstances indicate that the carrying value of the asset may not be recoverable
Purchased Loans	Purchased Loans Purchased performing loans that do not have evidence of deterioration in credit quality at acquisition are recorded at fair value at the acquisition date. Any premium or discount associated with purchased performing loans is recognized as an expense or income based on the effective yield method of amortization for term loans or the straight-line method of amortization for revolving loans. Subsequent to the purchase date, the methods utilized to estimate the required ALLL for these loans is similar to originated loans; however, we record a provision for loan and lease losses only when the required ALLL exceeds any remaining purchase discount at the product level. Purchased loans that have evidence of deterioration in credit quality since origination and for which it is probable, at acquisition, that all contractually required payments will not be collected, are deemed PCI. Revolving loans, including lines of credit and credit card loans, leases, and loans where cash flows cannot be reasonably estimated are excluded from PCI accounting. Purchased loans are initially recorded at fair value without recording an allowance for loan losses. Fair value of these loans is determined using market participant assumptions in estimating the amount and timing of both principal and interest cash flows expected to be collected, as adjusted for an estimate of future credit losses and prepayments, and then a market-based discount rate is applied to those cash flows. PCI loans that have similar risk characteristics, primarily credit risk, collateral type and interest rate risk, and are homogeneous in size, are pooled and accounted for as a single asset with a single composite interest rate and an aggregate expectation of cash flows. PCI loans that cannot be aggregated into a pool are accounted for individually. The excess of cash flows expected to be collected, measured as of the acquisition date, over the estimated fair value is referred to as the “accretable yield” and is recognized in interest income over the remaining life of the loan or pool using the effective yield method. Accordingly, PCI loans are not subject to classification as nonaccrual (and nonperforming) in the same manner as originated loans. Rather, acquired PCI loans are considered to be accruing loans because their interest income relates to the accretable yield recognized on the individual loan or pool and not to the contractual interest payments of the loan. The difference between the contractually required principal and interest payments as of the acquisition date and the cash flows expected to be collected is referred to as the “nonaccretable difference.” The nonaccretable difference, which is not accreted into income, reflects estimated future credit losses and uncollectible contractual payments over the life of the PCI loan. After we acquire loans determined to be PCI loans, actual cash collections are monitored to determine if they conform to management’s expectations. Revised cash flow expectations are prepared each quarter. A decrease in expected cash flows in subsequent periods may indicate impairment and would require us to establish an ALLL by recording a charge to the provision for loan and lease losses. An increase in expected cash flows in subsequent periods initially reduces any previously established ALLL by the increase in the present value of cash flows expected to be collected, and requires us to recalculate the amount of accretable yield for the PCI loan or pool. The adjustment of accretable yield due to an increase in expected cash flows is accounted for as a change in estimate. The additional cash flows expected to be collected are reclassified from the nonaccretable difference to the accretable yield, and the amount of periodic accretion is adjusted accordingly over the remaining life of the PCI loan or pool.
Premises and Equipment	Premises and EquipmentPremises and equipment, including leasehold improvements, are stated at cost less accumulated depreciation and amortization. We determine depreciation of premises and equipment using the straight-line method over the estimated useful lives of the particular assets. Leasehold improvements are amortized using the straight-line method over the shorter of their economic lives or terms of the leases. Premises and equipment are evaluated for impairment whenever events or circumstances indicate that the carrying value of the asset may not be recoverable.
Securities Financing Activities	Securities Financing Activities
Guarantees	Guarantees We recognize liabilities, which are included in “accrued expense and other liabilities” on the balance sheet, for the fair value of our obligations under certain guarantees issued.
Revenue Recognition	Revenue Recognition We recognize revenues as they are earned based on contractual terms, as transactions occur, or as services are provided and collectability is reasonably assured. Our principal source of revenue is interest income from loans and investments. We also earn noninterest income from various banking and financial services offered through both the Corporate and Community banks. Interest Income. The largest source of revenue for us is interest income. Interest income is primarily recognized on an accrual basis according to nondiscretionary formulas in written contracts, such as loan agreements or securities contracts. Noninterest Income. We earn noninterest income through a variety of financial and transaction services provided to corporate and consumer clients. Revenue is recorded for noninterest income based on the contractual terms for the service or transaction performed. In certain circumstances, noninterest income is reported net of associated expenses. Trust and Investment Services Income. Trust and investment services revenues include brokerage commissions, trust and asset management commissions, and insurance income. Revenue from trade execution and brokerage services is earned through commissions from trade execution on behalf of clients. Revenue from these transactions is recognized at the trade date. Any ongoing service fees are recognized on a monthly basis as services are performed. Trust and asset management services include asset custody and investment management services provided to individual and institutional customers. Revenue is recognized monthly based on a minimum annual fee, and the market value of assets in custody. Additional fees are recognized for transactional activity at a point in time. Insurance revenue is earned through commissions on insurance sales and third party administrative services. Based on the nature of the commission agreement with each insurance provider, we may recognize revenue from insurance commissions over-time or at a point in time. Revenue from third party administrative services is recognized over the life of the contract. Investment Banking and Debt Placement Fees. Investment banking and debt placement fees primarily represent revenues earned by KeyBanc Capital Markets for various corporate services including advisory, debt placement and underwriting. Revenues for these services are recorded at a point in time, upon completion of a contractually identified transaction, or when an advisory opinion is provided. Investment banking and debt placement costs are reported on a gross basis on within other expense on the income statement. Service Charges on Deposit Accounts. Revenue from service charges on deposit accounts is earned through cash management, wire transfer, and other deposit-related services; as well as overdraft, non-sufficient funds, account management and other deposit-related fees. Revenue is recognized for these services either over time, corresponding with deposit accounts’ monthly cycle, or at a point in time for transactional related services and fees. Certain reward costs are netted within revenues from service charges on deposits. Corporate Services Income. Corporate services income includes various ancillary service revenue including letter of credit fees, loan fees, and certain capital markets’ revenue. Revenue from these fees is recorded in a manner that reflects the timing of when transactions occur, and as services are provided. Cards and Payments. Cards and payments income includes interchange fees from consumer credit and debit cards processed through card association networks, merchant services, and other card related services. Interchange rates are generally set by the credit card associations and based on purchase volumes and other factors. Interchange fees are recognized as transactions occur. Certain card network costs and reward costs are netted within interchange revenues. Merchant services income represents account management fees and transaction fees charged to merchants for the processing of card association network transactions. Merchant services revenue is recognized as transactions occur, or as services are performed. Corporate-Owned Life Insurance Income. Income from corporate-owned life insurance primarily represents changes in the cash surrender value of life insurance policies held on certain key employees. Revenue is recognized in each period based on the change in the cash surrender value during the period.
Pension Costs	Pension Costs The Company utilizes its fiscal year-end as the measurement date for its pension and other postretirement employee benefit plans. At the measurement date, plan assets are determined based on fair value, generally representing observable market prices or the net asset value provided by the funds’ trustee or administrator. The actuarial cost method used to compute the pension liabilities and related expense is the projected unit credit method. The projected benefit obligation is principally determined based on the present value of projected benefit distributions at an assumed discount rate. We determine the assumed discount rate based on the rate of return on a hypothetical portfolio of high quality corporate bonds with interest rates and maturities that provide the necessary cash flows to pay benefits when due. Periodic pension expense (or income) includes service costs, interest costs based on the assumed discount rate, the expected return on plan assets based on an actuarially derived market-related value and amortization of actuarial gains and losses. Periodic pension expense (or income) is recorded in “other expense”. Pension accounting reflects the long-term nature of benefit obligations and the investment horizon of plan assets, and can have the effect of reducing earnings volatility related to short-term changes in interest rates and market valuations. Actuarial gains and losses include the impact of plan amendments and various unrecognized gains and losses which are deferred and amortized over the future service periods of active employees. We determine the expected return on plan assets using a calculated market-related value of plan assets that smooths what might otherwise be significant year-to-year volatility in net pension cost. Changes in the value of plan assets are not recognized in the year they occur. Rather, they are combined with any other cumulative unrecognized asset- and obligation-related gains and losses and reflected evenly in the market-related value during the five years after they occur as long as the market-related value does not vary more than 10% from the plan’s FVA.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation is measured using the fair value method of accounting on the grant date. The measured cost is recognized over the period during which the recipient is required to provide service in exchange for the award. We estimate expected forfeitures when stock-based awards are granted and record compensation expense only for awards that are expected to vest. Compensation expense related to awards granted to employees is recorded in “personnel expense” on the Consolidated Statements of Income while compensation expense related to awards granted to directors is recorded in “other expense.” We recognize compensation cost for stock-based, mandatory deferred incentive compensation awards using the accelerated method of amortization over a period of approximately 5 years (the current year performance period and a four -year vesting period, which generally starts in the first quarter following the performance period) for awards granted in 2012 and after. Employee stock options typically become exercisable at the rate of 25% per year, beginning one year after the grant date. Options expire no later than 10 years after their grant date. We recognize stock-based compensation expense for stock options with graded vesting using an accelerated method of amortization. We use shares repurchased under our annual capital plan submitted to our regulators (treasury shares) for share issuances under all stock-based compensation programs. We estimate the fair value of options granted using the Black-Scholes option-pricing model, as further described in Note 16 (“ Stock-Based Compensation
Income Taxes	Income Taxes Deferred tax assets and liabilities are determined based on temporary differences between financial statement asset and liability amounts and their respective tax bases, and are measured using enacted tax laws and rates that are expected to apply in the periods in which the deferred tax assets or liabilities are expected to be realized. Deferred tax assets are also recorded for any tax attributes, such as tax credit and net operating
Earnings Per Share	Earnings Per Share Basic net income per common share is calculated using the two-class method. The two-class method is an earnings allocation formula that determines earnings per share for each share of common stock and participating securities according to dividends declared (distributed earnings) and participation rights in undistributed earnings. Distributed and undistributed earnings are allocated between common and participating security shareholders based on their respective rights to receive dividends. Nonvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents are considered participating securities (e.g., nonvested service-based restricted stock units). Undistributed net losses are not allocated to nonvested restricted shareholders, as these shareholders do not have a contractual obligation to fund the incurred losses. Net income attributable to common shares is then divided by the weighted-average number of common shares outstanding during the period.
Accounting Guidance Adopted and Pending Adoption	Accounting Guidance Adopted in 2018 Standard Date of Adoption Description Effect on Financial Statements or Other Significant Matters ASU 2018-13, Fair Value Measurement: Disclosure Framework September 30, 2018 (removed disclosures only) An entity is permitted to early adopt any removed or modified disclosures upon issuance of this ASU and delay adoption of the additional disclosures until their effective date. The ASU amends disclosure requirements related to fair value measurements. Specifically, entities are no longer required to disclose transfers between Level 1 and Level 2 of the fair value hierarchy, or qualitatively disclose the valuation process for Level 3 fair value measurements. The updated guidance requires disclosure of the changes in unrealized gains and losses for the period included in Other Comprehensive Income for recurring Level 3 fair value measurements. Entities also will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. Key has early adopted the provisions of the standard related to disclosures no longer required by the guidance as of September 30, 2018, and anticipates early adopting the additional provisions of the standard in the first quarter of 2019. The adoption of this standard will not result in significant changes to Key’s disclosures and there will be no effect to our financial condition or results of operations. Standard Date of Adoption Description Effect on Financial Statements or Other Significant Matters ASU 2014-09, Revenue from Contracts with Customers (Topic 606) ASU 2015-14, Deferral of Effective Date ASU 2016-08, Principal versus Agent Considerations ASU 2016-10, Identifying Performance Obligations and Licensing ASU 2016-11, Rescission of SEC Guidance because of Accounting Standard Updates 2014-09 and 2014-16 pursuant to Staff Announcements at the March 3, 2016 EITF Meeting ASU 2016-12, Narrow-scope Improvements and Practical Expedients ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers January 1, 2018 These ASUs supersede the revenue recognition guidance in ASC 605, Revenue Recognition, and most industry-specific guidance. The core principle of these ASUs is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. These ASUs can be implemented using a retrospective method, or a cumulative-effect approach to new contracts and existing contracts with performance obligations as of the effective date. On January 1, 2018, we adopted ASC 606, Revenue from Contracts with Customers (ASC 606) , using the modified retrospective method for those contracts which were not completed as of that date. Results for reporting periods beginning January 1, 2018, are presented under ASC 606. As allowed under the new guidance, the comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. As a result of adopting ASC 606, we changed the timing of recognition for revenues related to insurance commissions, securities underwriting, and deposit account maintenance fees, however, those changes did not have a material impact on our consolidated financial statements, results of operations, equity, or cash flows as of the adoption date or for the year ended December 31, 2018. The presentation of underwriting costs and reimbursed out-of-pocket expenses related to underwriting and M&A advisory services was changed from net to gross within the income statement as Key acts as the principal in the transactions. Securities underwriting revenue is recorded within "investment banking and debt placement fees" and underwriting costs and reimbursed out-of-pocket expenses within "other expense" on the income statement. Additionally, because Key acts as an agent, certain credit and debit card reward costs and certain card network costs were changed from a gross presentation to net within "cards and payment income" on the income statement. Credit and debit card reward costs and card network costs were recorded as "other expense" on the income statement in prior periods. These changes in presentation did not have a material impact on our consolidated financial statements for the year ended December 31, 2018. ASC 606 requires quantitative disclosure of the allocation of the transaction price to the remaining performance obligations when those amounts are expected to be recognized as revenue. However, the standard provides exemptions from this disclosure for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services provided. Most of our revenue subject to ASC 606 fits into one of these exemptions, or is immaterial. We elected to use the optional exemption to not disclose the aggregate amount of the transaction price to remaining performance obligations. ASU 2017-12, Targeted Improvements to Accounting for Hedging Activities January 1, 2018 The ASU amends ASC Topic 815, Derivatives and Hedging , to simplify the requirements for hedge accounting and facilitate financial reporting that more closely aligns with an entity’s risk management activities. Key amendments include: eliminating the requirement to separately measure and report hedge ineffectiveness, requiring changes in the value of the hedging instrument to be presented in the same income statement line as the earnings effect of the hedged item, and the ability to measure the hedged item based on the benchmark interest rate component of the total contractual coupon for fair value hedges. Additional disclosures are also required for reporting periods subsequent to the date of adoption. The guidance should be implemented on a modified retrospective basis to existing hedge relationships as of the adoption date. On January 1, 2018, we adopted this ASU on a modified retrospective basis. Accordingly, our financial statements for the year ended December 31, 2018, include an immaterial cumulative-effect adjustment to decrease opening retained earnings to reflect the application of the new guidance as of January 1, 2018. The primary impact to Key at adoption was the election to measure the change in fair value of hedged items in fair value hedges on the basis of the benchmark interest rate component of contractual coupon cash flows. This change has resulted in a reduction of hedge ineffectiveness for impacted fair value hedges. Instruments designated as hedges are recorded at fair value and included in “accrued income and other assets” or “accrued expense and other liabilities” on the balance sheet. Under the revised guidance, the change in the fair value of an instrument designated as a fair value hedge is recorded in earnings at the same time and in the same income statement line as the offsetting change in the fair value of the hedged item. For cash flow hedges, the change in the fair value of an instrument designated as a cash flow hedge is initially recorded in AOCI on the balance sheet. This amount is subsequently reclassified into income when the hedged transaction affects earnings and is presented in the same income statement line item as the earnings effect of the hedged item. Standard Date of Adoption Description Effect on Financial Statements or Other Significant Matters ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities January 1, 2018 The ASU amends ASC Topic 825, Financial Instruments-Overall, and requires equity investments, except those accounted for under the equity method of accounting or consolidated, to be measured at fair value with changes recognized in net income. If there is no readily determinable fair value, the guidance allows entities to measure investments at cost less impairment, whereby impairment is based on a qualitative assessment. The guidance eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost and changes the presentation of financial assets and financial liabilities on the balance sheet or in the footnotes. If an entity has elected the fair value option to measure liabilities, the new accounting guidance requires the portion of the change in the fair value of a liability resulting from credit risk to be presented in OCI. With the exception of disclosure requirements that will be adopted prospectively, the ASU must be adopted on a modified retrospective basis. The adoption of this guidance did not have a material effect on our financial condition or results of operations. ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments January 1, 2018 The ASU amends ASC Topic 230, Statement of Cash Flows , and clarifies how cash receipts and cash payments in certain transactions should be presented and classified in the statement of cash flows. These specific transactions include, but are not limited to, debt prepayment or extinguishment costs, contingent considerations made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned life insurance policies, and distributions from equity method investees. This guidance also clarifies that in instances of cash flows with multiple aspects that cannot be separately identified, classification should be based on the activity that is likely to be the predominant source of or use of cash flow. The guidance should be implemented using a retrospective approach. The adoption of this guidance did not have a material effect on our financial condition or results of operations. ASU 2017-01, Clarifying the Definition of a Business January 1, 2018 The ASU amends Topic 805, Business Combinations, and clarifies the definition of a business and removes the requirement for a market participant to consider whether it could replace missing elements in an integrated set of assets and activities. The guidance states that if substantially all of the fair value of the assets acquired or disposed of is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. The guidance should be implemented using a prospective approach. The adoption of this guidance did not have a material effect on our financial condition or results of operations. ASU 2017-05, Other Income- Gains and Losses from the Derecognition of Nonfinancial Assets January 1, 2018 The ASU amends ASC Topic 610-20, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets, to clarify the scope of the Topic by clarifying the definition of the term "in substance nonfinancial asset" and also adding guidance for partial sales of nonfinancial assets. Under the new guidance, an entity will derecognize a nonfinancial asset when it does not have or ceases to have a controlling interest in the legal entity that holds the asset and when control of the asset has transferred in accordance with ASC 606. The ASU can be adopted on a retrospective or modified retrospective approach. We adopted the ASU using a modified retrospective approach. The adoption of this guidance did not have a material effect on our financial condition or results of operations. ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost January 1, 2018 The ASU amends ASC Topic 715, Compensation - Retirement Benefits , and requires service costs to be included in the same line item as certain other compensation costs related to services rendered by employees. We record compensation costs under personnel expense on the income statement. Other elements of net benefit cost should be presented separately. The guidance should be implemented on a retrospective basis. The adoption of this guidance did not have a material effect on our financial condition or results of operations. ASU 2017-09, Scope of Modification Accounting January 1, 2018 The ASU amends ASC Topic 718, Compensation - Stock Compensation , and clarifies when changes to terms and conditions for share-based payment awards should be accounted for as modifications. Under the new guidance, entities should apply the modification guidance unless the fair value of the modified award is the same as the fair value of the original award immediately before modification, the vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before modification, and the classification of the modified award (as equity or liability instrument) is the same as the classification of the original award immediately before modification. The guidance should be applied on a prospective basis. The adoption of this guidance did not have a material effect on our financial condition or results of operations.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	Accounting Guidance Adopted in 2018 Standard Date of Adoption Description Effect on Financial Statements or Other Significant Matters ASU 2018-13, Fair Value Measurement: Disclosure Framework September 30, 2018 (removed disclosures only) An entity is permitted to early adopt any removed or modified disclosures upon issuance of this ASU and delay adoption of the additional disclosures until their effective date. The ASU amends disclosure requirements related to fair value measurements. Specifically, entities are no longer required to disclose transfers between Level 1 and Level 2 of the fair value hierarchy, or qualitatively disclose the valuation process for Level 3 fair value measurements. The updated guidance requires disclosure of the changes in unrealized gains and losses for the period included in Other Comprehensive Income for recurring Level 3 fair value measurements. Entities also will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. Key has early adopted the provisions of the standard related to disclosures no longer required by the guidance as of September 30, 2018, and anticipates early adopting the additional provisions of the standard in the first quarter of 2019. The adoption of this standard will not result in significant changes to Key’s disclosures and there will be no effect to our financial condition or results of operations. Standard Date of Adoption Description Effect on Financial Statements or Other Significant Matters ASU 2014-09, Revenue from Contracts with Customers (Topic 606) ASU 2015-14, Deferral of Effective Date ASU 2016-08, Principal versus Agent Considerations ASU 2016-10, Identifying Performance Obligations and Licensing ASU 2016-11, Rescission of SEC Guidance because of Accounting Standard Updates 2014-09 and 2014-16 pursuant to Staff Announcements at the March 3, 2016 EITF Meeting ASU 2016-12, Narrow-scope Improvements and Practical Expedients ASU 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers January 1, 2018 These ASUs supersede the revenue recognition guidance in ASC 605, Revenue Recognition, and most industry-specific guidance. The core principle of these ASUs is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. These ASUs can be implemented using a retrospective method, or a cumulative-effect approach to new contracts and existing contracts with performance obligations as of the effective date. On January 1, 2018, we adopted ASC 606, Revenue from Contracts with Customers (ASC 606) , using the modified retrospective method for those contracts which were not completed as of that date. Results for reporting periods beginning January 1, 2018, are presented under ASC 606. As allowed under the new guidance, the comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. As a result of adopting ASC 606, we changed the timing of recognition for revenues related to insurance commissions, securities underwriting, and deposit account maintenance fees, however, those changes did not have a material impact on our consolidated financial statements, results of operations, equity, or cash flows as of the adoption date or for the year ended December 31, 2018. The presentation of underwriting costs and reimbursed out-of-pocket expenses related to underwriting and M&A advisory services was changed from net to gross within the income statement as Key acts as the principal in the transactions. Securities underwriting revenue is recorded within "investment banking and debt placement fees" and underwriting costs and reimbursed out-of-pocket expenses within "other expense" on the income statement. Additionally, because Key acts as an agent, certain credit and debit card reward costs and certain card network costs were changed from a gross presentation to net within "cards and payment income" on the income statement. Credit and debit card reward costs and card network costs were recorded as "other expense" on the income statement in prior periods. These changes in presentation did not have a material impact on our consolidated financial statements for the year ended December 31, 2018. ASC 606 requires quantitative disclosure of the allocation of the transaction price to the remaining performance obligations when those amounts are expected to be recognized as revenue. However, the standard provides exemptions from this disclosure for (i) contracts with an original expected length of one year or less and (ii) contracts for which we recognize revenue at the amount to which we have the right to invoice for services provided. Most of our revenue subject to ASC 606 fits into one of these exemptions, or is immaterial. We elected to use the optional exemption to not disclose the aggregate amount of the transaction price to remaining performance obligations. ASU 2017-12, Targeted Improvements to Accounting for Hedging Activities January 1, 2018 The ASU amends ASC Topic 815, Derivatives and Hedging , to simplify the requirements for hedge accounting and facilitate financial reporting that more closely aligns with an entity’s risk management activities. Key amendments include: eliminating the requirement to separately measure and report hedge ineffectiveness, requiring changes in the value of the hedging instrument to be presented in the same income statement line as the earnings effect of the hedged item, and the ability to measure the hedged item based on the benchmark interest rate component of the total contractual coupon for fair value hedges. Additional disclosures are also required for reporting periods subsequent to the date of adoption. The guidance should be implemented on a modified retrospective basis to existing hedge relationships as of the adoption date. On January 1, 2018, we adopted this ASU on a modified retrospective basis. Accordingly, our financial statements for the year ended December 31, 2018, include an immaterial cumulative-effect adjustment to decrease opening retained earnings to reflect the application of the new guidance as of January 1, 2018. The primary impact to Key at adoption was the election to measure the change in fair value of hedged items in fair value hedges on the basis of the benchmark interest rate component of contractual coupon cash flows. This change has resulted in a reduction of hedge ineffectiveness for impacted fair value hedges. Instruments designated as hedges are recorded at fair value and included in “accrued income and other assets” or “accrued expense and other liabilities” on the balance sheet. Under the revised guidance, the change in the fair value of an instrument designated as a fair value hedge is recorded in earnings at the same time and in the same income statement line as the offsetting change in the fair value of the hedged item. For cash flow hedges, the change in the fair value of an instrument designated as a cash flow hedge is initially recorded in AOCI on the balance sheet. This amount is subsequently reclassified into income when the hedged transaction affects earnings and is presented in the same income statement line item as the earnings effect of the hedged item. Standard Date of Adoption Description Effect on Financial Statements or Other Significant Matters ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities January 1, 2018 The ASU amends ASC Topic 825, Financial Instruments-Overall, and requires equity investments, except those accounted for under the equity method of accounting or consolidated, to be measured at fair value with changes recognized in net income. If there is no readily determinable fair value, the guidance allows entities to measure investments at cost less impairment, whereby impairment is based on a qualitative assessment. The guidance eliminates the requirement to disclose the methods and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost and changes the presentation of financial assets and financial liabilities on the balance sheet or in the footnotes. If an entity has elected the fair value option to measure liabilities, the new accounting guidance requires the portion of the change in the fair value of a liability resulting from credit risk to be presented in OCI. With the exception of disclosure requirements that will be adopted prospectively, the ASU must be adopted on a modified retrospective basis. The adoption of this guidance did not have a material effect on our financial condition or results of operations. ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments January 1, 2018 The ASU amends ASC Topic 230, Statement of Cash Flows , and clarifies how cash receipts and cash payments in certain transactions should be presented and classified in the statement of cash flows. These specific transactions include, but are not limited to, debt prepayment or extinguishment costs, contingent considerations made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of corporate-owned life insurance policies, and distributions from equity method investees. This guidance also clarifies that in instances of cash flows with multiple aspects that cannot be separately identified, classification should be based on the activity that is likely to be the predominant source of or use of cash flow. The guidance should be implemented using a retrospective approach. The adoption of this guidance did not have a material effect on our financial condition or results of operations. ASU 2017-01, Clarifying the Definition of a Business January 1, 2018 The ASU amends Topic 805, Business Combinations, and clarifies the definition of a business and removes the requirement for a market participant to consider whether it could replace missing elements in an integrated set of assets and activities. The guidance states that if substantially all of the fair value of the assets acquired or disposed of is concentrated in a single identifiable asset or a group of similar identifiable assets, the set is not a business. The guidance should be implemented using a prospective approach. The adoption of this guidance did not have a material effect on our financial condition or results of operations. ASU 2017-05, Other Income- Gains and Losses from the Derecognition of Nonfinancial Assets January 1, 2018 The ASU amends ASC Topic 610-20, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets, to clarify the scope of the Topic by clarifying the definition of the term "in substance nonfinancial asset" and also adding guidance for partial sales of nonfinancial assets. Under the new guidance, an entity will derecognize a nonfinancial asset when it does not have or ceases to have a controlling interest in the legal entity that holds the asset and when control of the asset has transferred in accordance with ASC 606. The ASU can be adopted on a retrospective or modified retrospective approach. We adopted the ASU using a modified retrospective approach. The adoption of this guidance did not have a material effect on our financial condition or results of operations. ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost January 1, 2018 The ASU amends ASC Topic 715, Compensation - Retirement Benefits , and requires service costs to be included in the same line item as certain other compensation costs related to services rendered by employees. We record compensation costs under personnel expense on the income statement. Other elements of net benefit cost should be presented separately. The guidance should be implemented on a retrospective basis. The adoption of this guidance did not have a material effect on our financial condition or results of operations. ASU 2017-09, Scope of Modification Accounting January 1, 2018 The ASU amends ASC Topic 718, Compensation - Stock Compensation , and clarifies when changes to terms and conditions for share-based payment awards should be accounted for as modifications. Under the new guidance, entities should apply the modification guidance unless the fair value of the modified award is the same as the fair value of the original award immediately before modification, the vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before modification, and the classification of the modified award (as equity or liability instrument) is the same as the classification of the original award immediately before modification. The guidance should be applied on a prospective basis. The adoption of this guidance did not have a material effect on our financial condition or results of operations.

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Basic and Diluted Earnings Per Common Share	Our basic and diluted earnings per Common Share are calculated as follows: Year ended December 31, dollars in millions, except per share amounts 2018 2017 2016 EARNINGS Income (loss) from continuing operations $ 1,859 $ 1,291 $ 789 Less: Net income (loss) attributable to noncontrolling interests — 2 (1 ) Income (loss) from continuing operations attributable to Key 1,859 1,289 790 Less: Dividends on preferred stock 66 70 37 Income (loss) from continuing operations attributable to Key common shareholders 1,793 1,219 753 Income (loss) from discontinued operations, net of taxes 7 7 1 Net income (loss) attributable to Key common shareholders $ 1,800 $ 1,226 $ 754 WEIGHTED-AVERAGE COMMON SHARES Weighted-average Common Shares outstanding (000) 1,040,890 1,072,078 927,816 Effect of common share options and other stock awards 13,792 16,515 10,720 Weighted-average common shares and potential Common Shares outstanding (000) (a) 1,054,682 1,088,593 938,536 EARNINGS PER COMMON SHARE Income (loss) from continuing operations attributable to Key common shareholders $ 1.72 $ 1.13 $ .81 Income (loss) from discontinued operations, net of taxes .01 .01 — Net income (loss) attributable to Key common shareholders (b) 1.73 1.14 .81 Income (loss) from continuing operations attributable to Key common shareholders — assuming dilution 1.70 1.12 .80 Income (loss) from discontinued operations, net of taxes .01 .01 — Net income (loss) attributable to Key common shareholders — assuming dilution (b) 1.71 1.13 .80 (a) Assumes conversion of Common Share options and other stock awards and/or convertible preferred stock, as applicable. (b)

Loan Portfolio (Tables)

Loan Portfolio (Tables)	12 Months Ended
	Dec. 31, 2018
Loans Receivables [Abstract]
Loans by Category	December 31, in millions 2018 2017 Commercial and industrial (a) $ 45,753 $ 41,859 Commercial real estate: Commercial mortgage 14,285 14,088 Construction 1,666 1,960 Total commercial real estate loans 15,951 16,048 Commercial lease financing (b) 4,606 4,826 Total commercial loans 66,310 62,733 Residential — prime loans: Real estate — residential mortgage 5,513 5,483 Home equity loans 11,142 12,028 Total residential — prime loans 16,655 17,511 Consumer direct loans 1,809 1,794 Credit cards 1,144 1,106 Consumer indirect loans 3,634 3,261 Total consumer loans 23,242 23,672 Total loans (c) $ 89,552 $ 86,405 (a) Loan balances include $132 million and $119 million of commercial credit card balances at December 31, 2018 , and December 31, 2017 , respectively. (b) Commercial lease financing includes receivables of $10 million and $24 million held as collateral for a secured borrowing at December 31, 2018 , and December 31, 2017 , respectively. Principal reductions are based on the cash payments received from these related receivables. Additional information pertaining to this secured borrowing is included in Note 19 (“ Long-Term Debt ”). (c) Total loans exclude loans in the amount of $1.1 billion at December 31, 2018 , and $1.3 billion at December 31, 2017
Composition of Net Investment in Direct Financing Leases	The composition of the net investment in direct financing leases is as follows: December 31, in millions 2018 2017 Direct financing lease receivables $ 3,658 $ 3,727 Unearned income (345 ) (323 ) Unguaranteed residual value 412 382 Deferred fees and costs 19 19 Net investment in direct financing leases $ 3,744 $ 3,805

Asset Quality (Tables)

Asset Quality (Tables)	12 Months Ended
	Dec. 31, 2018
Receivables [Abstract]
Financing Receivable Credit Quality Indicators	Commercial Credit Exposure — Excluding PCI Credit Risk Profile by Creditworthiness Category (a), (b) December 31, in millions Commercial and industrial RE — Commercial RE — Construction Commercial Lease Total RATING 2018 2017 2018 2017 2018 2017 2018 2017 2018 2017 Pass $ 44,138 $ 39,833 $ 13,672 $ 13,328 $ 1,537 $ 1,894 $ 4,557 $ 4,730 $ 63,904 $ 59,785 Criticized (Accruing) 1,402 1,790 354 482 125 38 41 90 1,922 2,400 Criticized (Nonaccruing) 152 153 81 30 2 2 8 6 243 191 Total $ 45,692 $ 41,776 $ 14,107 $ 13,840 $ 1,664 $ 1,934 $ 4,606 $ 4,826 $ 66,069 $ 62,376 (a) Credit quality indicators are updated on an ongoing basis and reflect credit quality information as of the dates indicated. (b) The term criticized refers to those loans that are internally classified by Key as special mention or worse, which are asset quality categories defined by regulatory authorities. These assets have an elevated level of risk and may have a high probability of default or total loss. Pass rated refers to all loans not classified as criticized. Consumer Credit Exposure — Excluding PCI Non-PCI Loans by Refreshed FICO Score (a) December 31, in millions Residential — Prime Consumer direct loans Credit cards Consumer indirect loans Total FICO SCORE 2018 2017 2018 2017 2018 2017 2018 2017 2018 2017 750 and above $ 9,794 $ 10,226 $ 549 $ 519 $ 521 $ 477 $ 1,647 $ 1,472 $ 12,511 $ 12,694 660 to 749 4,906 5,181 700 690 507 508 1,320 1,184 7,433 7,563 Less than 660 1,411 1,519 224 225 116 121 565 529 2,316 2,394 No Score 213 208 333 356 — — 102 76 648 640 Total $ 16,324 $ 17,134 $ 1,806 $ 1,790 $ 1,144 $ 1,106 $ 3,634 $ 3,261 $ 22,908 $ 23,291 (a) Borrower FICO scores provide information about the credit quality of our consumer loan portfolio as they provide an indication as to the likelihood that a debtor will repay their debts. The scores are obtained from a nationally recognized consumer rating agency and are presented in the above table at the dates indicated. Commercial Credit Exposure — PCI Credit Risk Profile by Creditworthiness Category (a), (b) December 31, in millions Commercial and industrial RE — Commercial RE — Construction Commercial Lease Total RATING 2018 2017 2018 2017 2018 2017 2018 2017 2018 2017 Pass $ 37 $ 41 $ 125 $ 153 $ 2 $ 26 — — $ 164 $ 220 Criticized 24 42 53 95 — — — — 77 137 Total $ 61 $ 83 $ 178 $ 248 $ 2 $ 26 — — $ 241 $ 357 (a) Credit quality indicators are updated on an ongoing basis and reflect credit quality information as of the dates indicated. (b) The term criticized refers to those loans that are internally classified by Key as special mention or worse, which are asset quality categories defined by regulatory authorities. These assets have an elevated level of risk and may have a high probability of default or total loss. Pass rated refers to all loans not classified as criticized. Consumer Credit Exposure — PCI PCI Loans by Refreshed FICO Score (a) December 31, in millions Residential — Prime Consumer direct loans Credit cards Consumer indirect loans Total FICO SCORE 2018 2017 2018 2017 2018 2017 2018 2017 2018 2017 750 and above $ 137 $ 149 — — — — — — $ 137 $ 149 660 to 749 95 117 $ 1 $ 2 — — — — 96 119 Less than 660 97 105 2 2 — — — — 99 107 No Score 2 6 — — — — — — 2 6 Total $ 331 $ 377 $ 3 $ 4 — — — — $ 334 $ 381 (a)
Past Due Loans Including Current Loans	The following aging analysis of current and past due loans as of December 31, 2018 , and December 31, 2017 , provides further information regarding Key’s credit exposure. Aging Analysis of Loan Portfolio (a) December 31, 2018 Current 30-59 Days Past Due (b) 60-89 Days Past Due (b) 90 and Greater Days Past Due (b) Non-performing Loans Total Past Due and Non-performing Loans Purchased Credit Impaired Total Loans (c), (d) in millions LOAN TYPE Commercial and industrial $ 45,375 $ 89 $ 31 $ 45 $ 152 $ 317 $ 61 $ 45,753 Commercial real estate: Commercial mortgage 13,957 27 17 25 81 150 178 14,285 Construction 1,646 — 13 3 2 18 2 1,666 Total commercial real estate loans 15,603 27 30 28 83 168 180 15,951 Commercial lease financing 4,580 12 1 4 9 26 — 4,606 Total commercial loans $ 65,558 $ 128 $ 62 $ 77 $ 244 $ 511 $ 241 $ 66,310 Real estate — residential mortgage $ 5,119 $ 11 $ 3 $ 4 $ 62 $ 80 $ 314 $ 5,513 Home equity loans 10,862 31 12 10 210 263 17 11,142 Consumer direct loans 1,780 11 5 6 4 26 3 1,809 Credit cards 1,119 6 5 12 2 25 — 1,144 Consumer indirect loans 3,573 31 7 3 20 61 — 3,634 Total consumer loans $ 22,453 $ 90 $ 32 $ 35 $ 298 $ 455 $ 334 $ 23,242 Total loans $ 88,011 $ 218 $ 94 $ 112 $ 542 $ 966 $ 575 $ 89,552 (a) Amounts in table represent recorded investment and exclude loans held for sale. Recorded investment represents the face amount of the loan increased or decreased by applicable accrued interest, net deferred loan fees and costs, and unamortized premium or discount, and reflects direct charge-offs. (b) Past due loan amounts exclude purchased impaired loans, even if contractually past due (or if we do not expect to collect principal or interest in full based on the original contractual terms), as we are currently accreting income over the remaining term of the loans. (c) Net of unearned income, net deferred loan fees and costs, and unamortized discounts and premiums. (d) Future accretable yield related to PCI loans is not included in the analysis of the loan portfolio. December 31, 2017 Current 30-59 Days Past Due (b) 60-89 Days Past Due (b) 90 and Greater Days Past Due (b) Non-performing Loans Total Past Due and Non-performing Loans Purchased Credit Impaired Total Loans (c), (d) in millions LOAN TYPE Commercial and industrial $ 41,444 $ 111 $ 34 $ 34 $ 153 $ 332 $ 83 $ 41,859 Commercial real estate: Commercial mortgage 13,750 26 13 21 30 90 248 14,088 Construction 1,919 4 9 — 2 15 26 1,960 Total commercial real estate loans 15,669 30 22 21 32 105 274 16,048 Commercial lease financing 4,791 23 4 2 6 35 — 4,826 Total commercial loans $ 61,904 $ 164 $ 60 $ 57 $ 191 $ 472 $ 357 $ 62,733 Real estate — residential mortgage $ 5,043 $ 16 $ 7 $ 4 $ 58 $ 85 $ 355 $ 5,483 Home equity loans 11,721 32 15 9 229 285 22 12,028 Consumer direct loans 1,768 9 4 5 4 22 4 1,794 Credit cards 1,081 7 5 11 2 25 — 1,106 Consumer indirect loans 3,199 33 7 3 19 62 — 3,261 Total consumer loans $ 22,812 $ 97 $ 38 $ 32 $ 312 $ 479 $ 381 $ 23,672 Total loans $ 84,716 $ 261 $ 98 $ 89 $ 503 $ 951 $ 738 $ 86,405 (a) Amounts in table represent recorded investment and exclude loans held for sale. Recorded investment represents the face amount of the loan increased or decreased by applicable accrued interest, net deferred loan fees and costs, and unamortized premium or discount, and reflects direct charge-offs. (b) Past due loan amounts exclude purchased impaired loans, even if contractually past due (or if we do not expect to collect principal or interest in full based on the original contractual terms), as we are currently accreting income over the remaining term of the loans. (c) Net of unearned income, net deferred loan fees and costs, and unamortized discounts and premiums. (d)
Breakdown of Individually Impaired Loans	The following tables set forth a further breakdown of individually impaired loans: December 31, 2018 December 31, 2017 Recorded Investment (a) Unpaid Principal Balance (b) Specific Allowance (c) Recorded Investment (a) Unpaid Principal Balance (b) Specific Allowance (c) in millions With no related allowance recorded: Commercial and industrial $ 118 $ 175 — $ 126 $ 153 — Commercial real estate: Commercial mortgage 64 70 — 12 18 — Total commercial real estate loans 64 70 — 12 18 — Total commercial loans 182 245 — 138 171 — Real estate — residential mortgage 4 5 — 17 17 — Home equity loans 49 56 — 56 56 — Consumer direct loans 1 1 — — — — Consumer indirect loans 2 4 — 2 2 — Total consumer loans 56 66 — 75 75 — Total loans with no related allowance recorded 238 311 — 213 246 — With an allowance recorded: Commercial and industrial 44 47 $ 5 10 28 $ 6 Commercial real estate: Commercial mortgage 2 3 1 — — — Total commercial real estate loans 2 3 1 — — — Total commercial loans 46 50 6 10 28 6 Real estate — residential mortgage 45 70 3 32 32 5 Home equity loans 78 85 8 61 61 9 Consumer direct loans 3 3 — 4 4 — Credit cards 3 3 — 2 2 — Consumer indirect loans 34 34 2 32 32 3 Total consumer loans 163 195 13 131 131 17 Total loans with an allowance recorded 209 245 19 141 159 23 Total $ 447 $ 556 $ 19 $ 354 $ 405 $ 23 (a) The Recorded Investment represents the face amount of the loan increased or decreased by applicable accrued interest, net deferred loan fees and costs, and unamortized premium or discount, and reflects direct charge-offs. This amount is a component of total loans on our consolidated balance sheet. (b) The Unpaid Principal Balance represents the customer’s legal obligation to us. (c) See Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Impaired Loans” for a description of the specific allowance methodology. The following table sets forth a further breakdown of average individually impaired loans reported by Key: Average Recorded Investment (a) Twelve Months Ended December 31, in millions 2018 2017 2016 Commercial and industrial $ 149 $ 210 $ 176 Commercial real estate: Commercial mortgage 39 9 8 Construction — — 3 Total commercial real estate loans 39 9 11 Total commercial loans 188 219 187 Real estate — residential mortgage 49 50 53 Home equity loans 122 121 125 Consumer direct loans 4 3 3 Credit cards 3 3 3 Consumer indirect loans 35 32 34 Total consumer loans 213 209 218 Total $ 401 $ 428 $ 405 (a)
Post-Modification Outstanding Recorded Investment by Concession Type for Our Commercial Accruing and Nonaccruing TDRs	The following table shows the period-end post-modification outstanding recorded investment by concession type for our commercial and consumer accruing and nonaccruing TDRs added during the periods indicated: Twelve Months Ended December 31, in millions 2018 2017 Commercial loans: Extension of maturity date $ 15 12 Payment or covenant modification/deferment 99 $ 46 Bankruptcy plan modification 7 31 Total $ 121 $ 89 Consumer loans: Interest rate reduction $ 27 $ 13 Forgiveness of principal — — Other 38 28 Total $ 65 $ 41 Total commercial and consumer TDRs $ 186 $ 130
Summary Of Post-Modification Outstanding Recorded Investment, Accruing And Nonaccruing TDRs	The following table summarizes the change in the post-modification outstanding recorded investment of our accruing and nonaccruing TDRs during the periods indicated: Year ended December 31, in millions 2018 2017 Balance at beginning of the period $ 317 $ 280 Additions 228 165 Payments (110 ) (111 ) Charge-offs (36 ) (17 ) Balance at end of period (a) $ 399 $ 317
Breakdown of Nonperforming TDRs by Loans Category	A further breakdown of TDRs included in nonperforming loans by loan category for the periods indicated are as follows: December 31, 2018 December 31, 2017 Number of Loans Pre-modification Outstanding Recorded Investment Post-modification Outstanding Recorded Investment Number Pre-modification Post-modification dollars in millions LOAN TYPE Nonperforming: Commercial and industrial 35 $ 121 $ 85 20 $ 109 $ 86 Commercial real estate: Real estate — commercial mortgage 6 66 62 8 16 12 Total commercial real estate loans 6 66 62 8 16 12 Total commercial loans 41 187 147 28 125 98 Real estate — residential mortgage 281 21 20 308 18 18 Home equity loans 1,142 66 63 1,025 64 57 Consumer direct loans 171 2 1 114 2 2 Credit cards 330 2 2 322 2 1 Consumer indirect loans 1,098 18 14 825 16 13 Total consumer loans 3,022 109 100 2,594 102 91 Total nonperforming TDRs 3,063 296 247 2,622 227 189 Prior-year accruing: (a) Commercial and industrial 11 37 32 4 30 13 Commercial real estate: Real estate — commercial mortgage 2 — — — — — Total commercial loans 13 37 32 4 30 13 Real estate — residential mortgage 491 36 30 484 31 31 Home equity loans 1,403 82 64 1,276 75 59 Consumer direct loans 79 4 3 48 3 2 Credit cards 479 3 1 430 1 1 Consumer indirect loans 556 33 22 320 31 22 Total consumer loans 3,008 158 120 2,558 141 115 Total prior-year accruing TDRs 3,021 195 152 2,562 171 128 Total TDRs 6,084 $ 491 $ 399 5,184 $ 398 $ 317 (a) All TDRs that were restructured prior to January 1, 2018 , and January 1, 2017 , are fully accruing.
Changes in Allowance for Loan and Lease Losses by Loan Category	The changes in the ALLL by loan category for the periods indicated are as follows: in millions December 31, 2017 Provision Charge-offs Recoveries December 31, 2018 Commercial and industrial $ 529 $ 125 $ (159 ) $ 37 $ 532 Real estate — commercial mortgage 133 27 (21 ) 3 142 Real estate — construction 30 1 — 2 33 Commercial lease financing 43 (2 ) (10 ) 5 36 Total commercial loans 735 151 (190 ) 47 743 Real estate — residential mortgage 7 1 (3 ) 2 7 Home equity loans 43 2 (21 ) 11 35 Consumer direct loans 28 31 (36 ) 7 30 Credit cards 44 41 (44 ) 7 48 Consumer indirect loans 20 14 (30 ) 16 20 Total consumer loans 142 89 (134 ) 43 140 Total ALLL — continuing operations 877 240 (a) (324 ) 90 883 Discontinued operations 16 8 (15 ) 5 14 Total ALLL — including discontinued operations $ 893 $ 248 $ (339 ) $ 95 $ 897 (a) Excludes a provision for losses on lending-related commitments of $6 million . in millions December 31, 2016 Provision Charge-offs Recoveries December 31, 2017 Commercial and industrial $ 508 $ 114 $ (133 ) $ 40 $ 529 Real estate — commercial mortgage 144 (2 ) (11 ) 2 133 Real estate — construction 22 9 (2 ) 1 30 Commercial lease financing 42 9 (14 ) 6 43 Total commercial loans 716 130 (160 ) 49 735 Real estate — residential mortgage 17 (11 ) (3 ) 4 7 Home equity loans 54 4 (30 ) 15 43 Consumer direct loans 24 32 (34 ) 6 28 Credit cards 38 45 (44 ) 5 44 Consumer indirect loans 9 27 (31 ) 15 20 Total consumer loans 142 97 (142 ) 45 142 Total ALLL — continuing operations 858 227 (a) (302 ) 94 877 Discontinued operations 24 10 (26 ) 8 16 Total ALLL — including discontinued operations $ 882 $ 237 $ (328 ) $ 102 $ 893 (a) Excludes a provision for losses on lending-related commitments of $2 million . in millions December 31, 2015 Provision Charge-offs Recoveries December 31, 2016 Commercial and industrial $ 450 $ 165 $ (118 ) $ 11 $ 508 Real estate — commercial mortgage 134 6 (5 ) 9 144 Real estate — construction 25 4 (9 ) 2 22 Commercial lease financing 47 4 (12 ) 3 42 Total commercial loans 656 179 (144 ) 25 716 Real estate — residential mortgage 18 2 (4 ) 1 17 Home equity loans 57 13 (30 ) 14 54 Consumer direct loans 20 26 (27 ) 5 24 Credit cards 32 37 (35 ) 4 38 Consumer indirect loans 13 10 (21 ) 7 9 Total consumer loans 140 88 (117 ) 31 142 Total ALLL — continuing operations 796 267 (a) (261 ) 56 858 Discontinued operations 28 13 (28 ) 11 24 Total ALLL — including discontinued operations $ 824 $ 280 $ (289 ) $ 67 $ 882 (a) Excludes a credit for losses on lending-related commitments of $1 million
Allowance for Loan and Lease Losses and Corresponding Loan Balances	A breakdown of the individual and collective ALLL and the corresponding loan balances for the periods indicated are as follows: Allowance Outstanding December 31, 2018 Individually Evaluated for Impairment Collectively Evaluated for Impairment Purchased Credit Impaired Loans Individually Evaluated for Impairment Collectively Evaluated for Impairment Purchased Credit Impaired in millions Commercial and industrial $ 5 $ 526 $ 1 $ 45,753 $ 162 $ 45,530 $ 61 Commercial real estate: Commercial mortgage — 139 3 14,285 66 14,041 178 Construction — 33 — 1,666 — 1,664 2 Total commercial real estate loans — 172 3 15,951 66 15,705 180 Commercial lease financing — 36 — 4,606 — 4,606 — Total commercial loans 5 734 4 66,310 228 65,841 241 Real estate — residential mortgage 3 4 — 5,513 49 5,150 314 Home equity loans 8 26 1 11,142 127 10,998 17 Consumer direct loans — 30 — 1,809 4 1,802 3 Credit cards — 48 — 1,144 3 1,141 — Consumer indirect loans 3 17 — 3,634 36 3,598 — Total consumer loans 14 125 1 23,242 219 22,689 334 Total ALLL — continuing operations 19 859 5 89,552 447 88,530 575 Discontinued operations 2 12 — 1,073 (a) 23 1,050 (a) — Total ALLL — including discontinued operations $ 21 $ 871 $ 5 $ 90,625 $ 470 $ 89,580 $ 575 (a) Amount includes $2 million of loans carried at fair value that are excluded from ALLL consideration. Allowance Outstanding December 31, 2017 Individually Evaluated for Impairment Collectively Evaluated for Impairment Purchased Credit Impaired Loans Individually Evaluated for Impairment Collectively Evaluated for Impairment Purchased Credit Impaired in millions Commercial and industrial $ 6 $ 520 $ 3 $ 41,859 $ 136 $ 41,640 $ 83 Commercial real estate: Commercial mortgage — 131 2 14,088 12 13,828 248 Construction — 30 — 1,960 — 1,934 26 Total commercial real estate loans — 161 2 16,048 12 15,762 274 Commercial lease financing — 43 — 4,826 — 4,826 — Total commercial loans 6 724 5 62,733 148 62,228 357 Real estate — residential mortgage 5 2 — 5,483 49 5,079 355 Home equity loans 9 33 1 12,028 117 11,889 22 Consumer direct loans — 28 — 1,794 4 1,786 4 Credit cards — 44 — 1,106 2 1,104 — Consumer indirect loans 3 17 — 3,261 34 3,227 — Total consumer loans 17 124 1 23,672 206 23,085 381 Total ALLL — continuing operations 23 848 6 86,405 354 85,313 738 Discontinued operations 3 13 — 1,314 (a) 21 1,293 (a) — Total ALLL — including discontinued operations $ 26 $ 861 $ 6 $ 87,719 $ 375 $ 86,606 $ 738 (a) Amount includes $2 million of loans carried at fair value that are excluded from ALLL consideration.
Changes in Liability for Credit Losses on Lending Related Commitments	Changes in the liability for credit losses on unfunded lending-related commitments are summarized as follows: Year ended December 31, in millions 2018 2017 2016 Balance at beginning of period $ 57 $ 55 $ 56 Provision (credit) for losses on lending-related commitments 6 2 (1 ) Balance at end of period $ 63 $ 57 $ 55
Schedule of Changes in Outstanding Unpaid Principal Balance, Carrying Amount, and Accretable Yield	We have PCI loans from two separate acquisitions, one in 2012 and one in 2016. The following tables present the rollforward of the accretable yield and the beginning and ending outstanding unpaid principal balance and carrying amount of all PCI loans for the for the periods indicated: Twelve Months Ended December 31, 2018 2017 in millions Accretable Yield Carrying Amount Outstanding Unpaid Principal Balance Accretable Yield Carrying Amount Outstanding Unpaid Principal Balance Balance at beginning of period $ 131 $ 738 $ 803 $ 197 $ 865 $ 1,002 Additions — (32 ) Accretion (42 ) (44 ) Net reclassifications from non-accretable to accretable 50 15 Payments received, net (21 ) (4 ) Disposals — (1 ) Loans charged off (1 ) — Balance at end of period $ 117 $ 571 $ 607 $ 131 $ 738 $ 803

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities Measured on Recurring Basis	The following tables present assets and liabilities measured at fair value on a recurring basis at December 31, 2018 , and December 31, 2017 . December 31, 2018 December 31, 2017 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total in millions ASSETS MEASURED ON A RECURRING BASIS Trading account assets: U.S. Treasury, agencies and corporations — $ 578 — $ 578 — $ 615 — $ 615 States and political subdivisions — 60 — 60 — 37 — 37 Other mortgage-backed securities — 164 — 164 — 104 — 104 Other securities — 22 — 22 — 65 — 65 Total trading account securities — 824 — 824 — 821 — 821 Commercial loans — 25 — 25 — 15 — 15 Total trading account assets — 849 — 849 — 836 — 836 Securities available for sale: U.S. Treasury, agencies and corporations — 147 — 147 — 157 — 157 States and political subdivisions — 7 — 7 — 9 — 9 Agency residential collateralized mortgage obligations — 13,962 — 13,962 — 14,660 — 14,660 Agency residential mortgage-backed securities — 2,105 — 2,105 — 1,439 — 1,439 Agency commercial mortgage-backed securities — 3,187 — 3,187 — 1,854 — 1,854 Other securities — — $ 20 20 — — $ 20 20 Total securities available for sale — 19,408 20 19,428 — 18,119 20 18,139 Other investments: Principal investments: Direct — — 1 1 — — 13 13 Indirect (measured at NAV) (a) — — — 96 — — — 124 Total principal investments — — 1 97 — — 13 137 Equity investments: Direct — 1 7 8 — 4 3 7 Direct (measured at NAV) (a) — — — 1 — — — — Indirect (measured at NAV) (a) — — — 9 — — — — Total equity investments — 1 7 18 — 4 3 7 Total other investments — 1 8 115 — 4 16 144 Loans, net of unearned income (residential) — — 3 3 — — 2 2 Loans held for sale (residential) — 54 — 54 — 70 1 71 Derivative assets: Interest rate — 410 5 415 — 713 9 722 Foreign exchange $ 70 36 — 106 $ 100 $ 30 $ — $ 130 Commodity — 333 — 333 — 255 — 255 Credit — 1 — 1 — — 1 1 Other — 6 3 9 — 1 3 4 Derivative assets 70 786 8 864 100 999 13 1,112 Netting adjustments (b) — — — (333 ) — — — (443 ) Total derivative assets 70 786 8 531 100 999 13 669 Total assets on a recurring basis at fair value $ 70 $ 21,098 $ 39 $ 20,980 $ 100 $ 20,028 $ 52 $ 19,861 LIABILITIES MEASURED ON A RECURRING BASIS Bank notes and other short-term borrowings: Short positions $ 14 $ 530 — $ 544 $ 72 $ 562 — $ 634 Derivative liabilities: Interest rate — 297 — 297 — 520 — 520 Foreign exchange 58 37 — 95 98 26 — 124 Commodity — 323 — 323 — 246 — 246 Credit — 1 — 1 — 4 — 4 Other — 7 — 7 — 13 — 13 Derivative liabilities 58 665 — 723 98 809 — 907 Netting adjustments (b) — — — (337 ) — — — (616 ) Total derivative liabilities 58 665 — 386 98 809 — 291 Total liabilities on a recurring basis at fair value $ 72 $ 1,195 — $ 930 $ 170 $ 1,371 — $ 925 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the consolidated balance sheet. (b)
Fair Value Measurement Inputs and Valuation Techniques	The following table describes the valuation techniques and significant inputs used to measure the significant classes of assets and liabilities reported at fair value on a nonrecurring basis, as well as the classification of each within the valuation hierarchy. Asset/liability class Valuation technique Valuation hierarchy classification(s) Impaired loans and leases Loans are evaluated for impairment on a quarterly basis; impairment typically occurs when there is evidence of a probable loss and the expected value of the loan is less than the contractual value of the loan. The amount of the impairment may be determined based on the estimated present value of future cash flows, the fair value of the underlying collateral, or the loan’s observable market price based on recent sales of similar loans and collateral. Cash flow analysis considers internally developed inputs including: • Discount rates • Default rates • Costs of foreclosure • Changes in collateral values The fair value of the underlying collateral, which may take the form of real estate or personal property, is based on internal estimates, field observations, and assessments provided by third-party appraisers. We perform or reaffirm appraisals of collateral-dependent impaired loans at least annually. Appraisals may occur more frequently if the most recent appraisal does not accurately reflect the current market, the debtor is seriously delinquent or chronically past due, or there has been a material deterioration in the performance of the project or condition of the property. Adjustments to outdated appraisals that result in an appraisal value less than the carrying amount of a collateral-dependent impaired loan are reflected in the ALLL. Impaired loans with a specifically allocated allowance based on a cash flow analysis or the value of the underlying collateral are classified as Level 3 assets. Impaired loans with a specifically allocated allowance based on an observable market price that reflects recent sale transactions for similar loans and collateral are classified as Level 2 assets. We adjust the carrying amount of our impaired loans when there is evidence of probable loss and the expected fair value of the loan is less than its contractual amount. Level 2 and 3 Commercial loans held for sale Through a quarterly analysis of our loan portfolios held for sale, which include both performing and nonperforming commercial loans, we determine any adjustments necessary to record the portfolios at the lower of cost or fair value in accordance with GAAP. Valuation inputs include: • Non-binding bids for the respective loans or similar loans • Recent sales transactions • Internal models that emulate recent securitizations Level 2 and 3 Direct financing leases and operating lease assets held for sale Valuations of direct financing leases and operating lease assets held for sale are performed using an internal model that relies on market data, including: • Swap rates and bond ratings • Our own assumptions about the exit market for the leases • Details about the individual leases in the portfolio KEF has master sale and assignment agreements with numerous institutional investors. Historically, multiple quotes are obtained, with the most reasonable formal quotes retained. These nonbinding quotes generally lead to a sale to one of the parties who provided the quote. Leases for which we receive a current nonbinding bid, and for which the sale is considered probable, may be classified as Level 2. The validity of these quotes is supported by historical and continued dealings with institutions that have fulfilled the nonbinding quote in the past. Valuations of lease and operating lease assets held for sale that employ our own assumptions are classified as Level 3 assets. Inputs utilized include changes in the value of leased items and internal credit ratings. In an inactive market, we value assets held for sale through discounted cash flows models that utilize the current buy rate as the discount rate. Buy rates are based on the credit premium inherent in the relevant bond index and the the appropriate swap rate on the measurement date. Level 2 and 3 Asset/liability class Valuation technique Valuation hierarchy classification(s) OREO and other repossessed personal property OREO and other repossessed properties are valued based on: • Appraisals and third-party price opinions, less estimated selling costs Generally, we classify these assets as Level 3, but OREO and other repossessed properties for which we receive binding purchase agreements are classified as Level 2. Returned lease inventory is valued based on market data for similar assets and is classified as Level 2. Assets that are acquired through, or in lieu of, loan foreclosures are recorded initially as held for sale at fair value less estimated selling costs at the date of foreclosure. After foreclosure, valuations are updated periodically, and current market conditions may require the assets to be marked down further to a new cost basis. Level 2 and 3 LIHTC, HTC, and NMTC investments LIHTC, HTC and NMTC operating partnerships are subject to quarterly impairment testing. This evaluation involves measuring the present value of future tax benefits and comparing that value against the current carrying value of the investment. Expected future tax benefit schedules are provided by the partnerships’ general partners on a quarterly basis. These future benefits are discounted to their present value using discounted cash flow modeling that incorporates an appropriate risk premium. LIHTC and HTC investments are impaired when it is more likely than not that the carrying amount of the investment will not be realized. A primary driver of impairment in the fourth quarter of 2017 was the enactment of the TCJ Act, which reduced future depreciation tax benefits expected to be realized by certain LIHTC and HTC investments. Level 3 Other equity investments We have other investments in equity securities that do not have readily determinable fair values and do not qualify for the practical expedient to measure the investment using a net asset value per share. We have elected to measure these securities at cost less impairment plus or minus adjustments due to observable orderly transactions. Impairment is recorded when there is evidence that the expected fair value of the investment has declined to below the recorded cost. At each reporting period, we assess if these investments continue to qualify for this measurement alternative. At December 31, 2018, the carrying amount of equity investments recorded under this method was $107 million. No impairment was recorded for the year ended December 31, 2018. Level 3 Mortgage Servicing Rights Refer to Note 9. Mortgage Servicing Assets Level 3 Asset/liability class Valuation technique Valuation hierarchy classification(s) Securities (trading account assets and available for sale) Fair value of level 1 securities is determined by: • Quoted market prices available in an active market for identical securities. This includes exchange-traded equity securities. Fair value of level 2 securities is determined by: • Pricing models (either by a third party pricing service or internally). Inputs include: yields, benchmark securities, bids, offers, actual trade data (i.e., spreads, credit ratings, and interest rates) for comparable assets, spread tables, matrices, high-grade scales, and option-adjusted spreads. • Observable market prices of similar securities. Fair value of level 3 securities is determined by: • Internal models, principally discounted cash flow models (income approach). • Revenue multiples of comparable public companies (market approach). For level 3 securities, increases in the discount rate applied in the discounted cash flow models would negatively affect the fair value. Increases in valuation multiples of comparable companies would positively affect the fair value. The valuations provided by the third-party pricing service are based on observable market inputs, which include benchmark yields, reported trades, issuer spreads, benchmark securities, bids, offers, and reference data obtained from market research publications. Inputs used by the third-party pricing service in valuing CMOs and other mortgage-backed securities also include new issue data, monthly payment information, whole loan collateral performance, and “To Be Announced” prices. In valuations of securities issued by state and political subdivisions, inputs used by the third-party pricing service also include material event notices. Level 1, 2, and 3 (primarily Level 2) Commercial loans (trading account assets) Fair value is based on: • Observable market price spreads for similar loans. Valuations reflect prices within the bid-ask spread that are most representative of fair value. Level 2 Principal investments (direct) Direct principal investments consist of equity and debt instruments of private companies made by our principal investing entities. Fair value is determined using: • Operating performance and market multiples of comparable businesses • Other unique facts and circumstances related to each individual investment Direct principal investments are accounted for as investment companies in accordance with the applicable accounting guidance, whereby each investment is adjusted to fair value with any net realized or unrealized gain/loss recorded in the current period’s earnings. We are in the process of winding down our direct principal investment portfolio. As of December 31, 2018, the balance is less than $1 million. Level 3 Principal investments (indirect) Indirect principal investments include primary and secondary investments in private equity funds engaged mainly in venture- and growth-oriented investing. These investments do not have readily determinable fair values and qualify for the practical expedient to estimate fair value based upon net asset value per share (or its equivalent, such as member units or an ownership interest in partners’ capital to which a proportionate share of net assets is attributed). Indirect principal investments are also accounted for as investment companies, whereby each investment is adjusted to fair value with any net realized or unrealized gain/loss recorded in the current period’s earnings. Under the provisions of the Volcker Rule, we are required to dispose or conform our indirect investments to the requirements of the statute by no later than July 21, 2022. As of December 31, 2018, we have not committed to a plan to sell these investments. Therefore, these investments continue to be valued using the net asset value per share methodology. NAV December 31, 2018 , and December 31, 2017 , along with the valuation techniques used, are shown in the following table: December 31, 2018 Fair Value of Level 3 Assets Valuation Technique Significant Unobservable Input Range (Weighted-Average) Dollars in millions Nonrecurring Impaired loans $ 42 Fair value of underlying collateral Discount 20.00 - 40.00% (21.00%) December 31, 2017 Fair Value of Level 3 Assets Valuation Technique Significant Unobservable Input Range (Weighted-Average) dollars in millions Recurring Other investments — principal investments — direct: $ 13 Individual analysis of the condition of each investment Debt instruments EBITDA multiple N/A (6.00) Equity instruments of private companies EBITDA multiple N/A (6.00) Nonrecurring Impaired loans $ 9 Fair value of underlying collateral Discount 0.00 - 50.00% (23.00%) Asset/liability class Valuation technique Valuation hierarchy classification(s) Other direct equity investments Fair value is determined using: • Discounted cash flows • Operating performance and market/exit multiples of comparable businesses • Other unique facts and circumstances related to each individual investment For level 3 securities, increases in the discount rate applied in the discounted cash flow models would negatively affect the fair value. Increases in valuation multiples of comparable companies would positively affect the fair value. Level 2 investments reflect the price of recent investments, which is deemed representative of fair value. Level 2 and 3 Other direct and indirect equity investments (NAV) Certain direct investments do not have readily determinable fair values and qualify for the practical expedient in the accounting guidance that allows us to estimate fair value based upon net asset value per share. NAV Loans held for sale and held for investment (residential) Residential mortgage loans held for sale are accounted for at fair value. Fair values are based on: • Quoted market prices, where available • Prices for other traded mortgage loans with similar characteristics • Purchase commitments and bid information received from market participants Prices are adjusted as necessary to include: • The embedded servicing value in the loans • The specific characteristics of certain loans that are priced based on the pricing of similar loans. (These adjustments represent unobservable inputs to the valuation but are not considered significant given the relative insensitivity of the value to changes in these inputs to the fair value of the loans.) Residential loans held for investment: Certain residential loans held for sale contain salability exceptions that make them unable to be sold into the performing loan sales market. Loans in this category are transferred to the held to maturity loan portfolio and are included in “Loans, net of unearned income” on the balance sheet. This type of loan is classified as level 3 in the valuation hierarchy as transaction details regarding sales of this type of loan are often unavailable. Fair value is based upon: • Unobservable bid information from brokers and investors Level 1, 2 and 3 (primarily level 2) Derivatives Exchange-traded derivatives are valued using quoted prices in active markets and, therefore, are classified as Level 1 instruments. The majority of our derivative positions are level 2 and are valued using internally developed models based on market convention and observable market inputs. These derivative contracts include interest rate swaps, certain options, floors, cross currency swaps, credit default swaps, and forward mortgage loan sale commitments. Significant inputs used in the valuation models include: • Interest rate curves • Yield curves • LIBOR and Overnight Index Swap (OIS) discount rates • LIBOR and OIS curves, index pricing curves, foreign currency curves • Volatility surfaces (a three-dimensional graph of implied volatility against strike price and maturity) • Current prices for mortgage securities and investor supplied prices Level 1, 2, and 3 (primarily level 2) Asset/liability class Valuation technique Valuation hierarchy classification(s) Derivatives (continued) We have several customized derivative instruments and risk participations that are classified as Level 3 instruments. These derivative positions are valued using internally developed models, with inputs consisting of available market data, such as: • Bond spreads and asset values The unobservable internally derived assumptions include: • Loss probabilities • Internal risk ratings of customers The fair value represents an estimate of the amount that the risk participation counterparty would need to pay/receive as of the measurement date based on the probability of customer default on the swap transaction and the fair value of the underlying customer swap. Therefore, a higher loss probability and a lower credit rating would negatively affect the fair value of the risk participations and a lower loss probability and higher credit rating would positively affect the fair value of the risk participations. We use interest rate lock commitments for our residential mortgage business, which are classified as Level 3 instruments. The significant components of the valuation model include: • Interest rates observable in the market • Observable market prices for similar securities • The probability of the loan closing (i.e. the "pull-through" amount, a significant unobservable input). Increases in the probability of the loan closing would positively affect the fair value. Valuation of residential mortgage forward sale commitments utilizes observable market prices of comparable commitments and mortgage securities (Level 2). Level 1, 2, and 3 (primarily level 2) Liability for short positions This includes fixed income securities held by our broker dealer in its trading inventory. Fair value of level 1 securities is determined by: • Quoted market prices available in an active market for identical securities Fair value of level 2 securities is determined by: • Observable market prices of similar securities • Market activity, spreads, credit ratings and interest rates for each security type Level 1 and 2
Fair Values Of Funds And Unfunded Commitments	The following table presents the fair value of our direct and indirect principal investments and related unfunded commitments at December 31, 2018 , as well as financial support provided for the years ended December 31, 2018 , and December 31, 2017 . Financial support provided Year ended December 31, December 31, 2018 2018 2017 in millions Fair Value Unfunded Commitments Funded Commitments Funded Other Funded Commitments Funded Other INVESTMENT TYPE Direct investments (a) $ 1 — — — — $ — Indirect investments (b) 96 $ 26 $ 1 — $ 1 — Total $ 97 $ 26 $ 1 — $ 1 $ — (a) Our direct investments consist of equity and debt investments directly in independent business enterprises. Operations of the business enterprises are handled by management of the portfolio company. The purpose of funding these enterprises is to provide financial support for business development and acquisition strategies. We infuse equity capital based on an initial contractual cash contribution and later from additional requests on behalf of the companies’ management. (b) Our indirect investments consist of buyout funds, venture capital funds, and fund of funds. These investments are generally not redeemable. Instead, distributions are received through the liquidation of the underlying investments of the fund. An investment in any one of these funds typically can be sold only with the approval of the fund’s general partners. At December 31, 2018
Change in Fair Values of Level 3 Financial Instruments	The following table shows the change in the fair values of our Level 3 financial instruments for the years ended December 31, 2018 , and December 31, 2017 . in millions Beginning of Period Balance Gains (Losses) included in comprehensive income Gains (Losses) Included in Earnings Purchases Sales Settlements Transfers Other Transfers into Level 3 (e) Transfers out of Level 3 (e) End of Period Balance Unrealized Gains (Losses) Included in Earnings Year ended December 31, 2018 Securities available for sale Other securities $ 20 — — — — — — — — $ 20 — Other investments Principal investments Direct 13 — $ (1 ) (c) $ 5 $ (16 ) — — — — 1 — (c) Equity investments Direct 3 — — — — — — $ 4 — 7 — Loans held for sale 1 — — — (1 ) — $ (1 ) 1 — — — Loans held for investment 2 — — — — — 1 — — 3 — Derivative instruments (b) Interest rate 9 — (2 ) (d) 1 (2 ) — — 7 (f) $ (8 ) (f) 5 — Credit 1 — (31 ) (d) — — $ 30 — — — — — Other (a) 3 — — — — — — — — 3 — in millions Beginning of Period Balance Gains (Losses) included in comprehensive income Gains (Losses) Included in Earnings Purchases Sales Settlements Transfers Other Transfers into Level 3 (e) Transfers out of Level 3 (e) End of Period Balance Unrealized Gains (Losses) Included in Earnings Year ended December 31, 2017 Securities available for sale Other securities $ 17 $ 3 — — — — — — — $ 20 — Other investments Principal investments Direct 27 — $ (6 ) (c) — $ (8 ) — — — — 13 $ (1 ) (c) Equity investments Direct — — — (c) — — — — $ 3 — 3 — (c) Loans held for sale — — — — (3 ) — $ 4 — — 1 — Loans held for investment — — — — — — 2 — — 2 — Derivative instruments (b) Interest rate 7 — (2 ) (d) $ — — — — 13 (f) $ (9 ) (f) 9 — Credit 1 — (16 ) (d) — — $ 16 — — — 1 — Other (a) 2 — — — — — $ 1 — — 3 — (a) Amounts represent Level 3 interest rate lock commitments. (b) Amounts represent Level 3 derivative assets less Level 3 derivative liabilities. (c) Realized and unrealized gains and losses on principal investments are reported in “other income” on the income statement. Realized and unrealized losses on equity investments are reported in “other income” on the income statement. (d) Realized and unrealized gains and losses on derivative instruments are reported in “corporate services income” and “other income” on the income statement. (e) Our policy is to recognize transfers into and transfers out of Level 3 as of the end of the reporting period. (f) Certain derivatives previously classified as Level 2 were transferred to Level 3 because Level 3 unobservable inputs became significant. Certain derivatives previously classified as Level 3 were transferred to Level 2 because Level 3 unobservable inputs became less significant.
Assets and Liabilities Measured at Fair Value on Nonrecurring Basis	The following table presents our assets measured at fair value on a nonrecurring basis at December 31, 2018 , and December 31, 2017 : December 31, 2018 December 31, 2017 in millions Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ASSETS MEASURED ON A NONRECURRING BASIS Impaired loans and leases — — $ 42 $ 42 — — $ 9 $ 9 Accrued income and other assets — — 16 16 — $ 5 133 (a) 138 Total assets on a nonrecurring basis at fair value — — $ 58 $ 58 — $ 5 $ 142 $ 147 (a) At December 31, 2017, we recorded $31 million of impairment related to $119 million of LIHTC and Historic Tax Credit investments impacted by the enactment of the TCJ Act. Refer to the “LIHTC, HTC, and NMTC investments” section below for a description of the valuation technique and inputs applied for this fair value measurement.
Fair Value Disclosures of Financial Instruments	The levels in the fair value hierarchy ascribed to our financial instruments and the related carrying amounts at December 31, 2018 , and December 31, 2017 , are shown in the following table. December 31, 2018 Fair Value in millions Carrying Amount Level 1 Level 2 Level 3 Measured at NAV Netting Adjustment Total ASSETS (by measurement category) Fair value - net income Trading account assets (b) $ 849 — $ 849 — — — $ 849 Other investments (b) 666 — 1 $ 559 $ 106 — 666 Loans, net of unearned income (residential) (d) 3 — — 3 — — 3 Loans held for sale (residential) (b) 54 — 54 — — — 54 Derivative assets - trading (b) 462 $ 68 736 8 — $ (350 ) (f) 462 Fair value - OCI Securities available for sale (b) 19,428 — 19,408 20 — — 19,428 Derivative assets - hedging (b) (g) 69 2 50 — — 17 (f) 69 Amortized cost Held-to-maturity securities (c) 11,519 — 11,122 — — — 11,122 Loans, net of unearned income (d) 88,666 — — 86,224 — — 86,224 Loans held for sale (b) 1,173 — — 1,173 — — 1,173 Other Cash and short-term investments (a) 3,240 3,240 — — — — 3,240 LIABILITIES (by measurement category) Fair value - net income Derivative liabilities - trading (b) $ 395 $ 58 $ 675 — — $ (338 ) (f) $ 395 Fair value - OCI Derivative liabilities - hedging (b) (g) (9 ) — (10 ) — — 1 (f) (9 ) Amortized cost Time deposits (e) 13,245 — 13,331 — — — 13,331 Short-term borrowings (a) 863 14 849 — — — 863 Long-term debt (e) 13,732 12,576 1,211 — — — 13,787 Other Deposits with no stated maturity (a) 94,064 — 94,064 — — — 94,064 December 31, 2017 Fair Value in millions Carrying Amount Level 1 Level 2 Level 3 Measured at NAV Netting Adjustment Total ASSETS (by measurement category) Fair value - net income Trading account assets (b) $ 836 — $ 836 — — — $ 836 Other investments (b) 726 — 4 $ 598 $ 124 — 726 Loans, net of unearned income (residential) (d) 2 — — 2 — — 2 Loans held for sale (residential) (b) 71 — 70 1 — — 71 Derivative assets - trading (b) 681 $ 99 918 13 — $ (349 ) (f) 681 Fair value - OCI Securities available for sale (b) 18,139 — 18,119 20 — — 18,139 Derivative assets - hedging (b) (g) (12 ) 1 81 — — (94 ) (f) (12 ) Amortized cost Held-to-maturity securities (c) 11,830 — 11,565 — — — 11,565 Loans, net of unearned income (d) 85,526 — — 84,003 — — 84,003 Loans held for sale (b) 1,036 — — 1,036 — — 1,036 Other Cash and short-term investments (a) 5,118 5,118 — — — — 5,118 LIABILITIES (by measurement category) Fair value - net income Derivative liabilities - trading (b) $ 289 $ 94 $ 763 — — $ (568 ) (f) $ 289 Fair value - OCI Derivative liabilities - hedging (b) (g) 2 4 46 — — (48 ) (f) 2 Amortized cost Time deposits (e) 11,647 — 11,750 — — — 11,750 Short-term borrowings (a) 1,011 72 939 — — — 1,011 Long-term debt (e) 14,333 13,407 $ 1,219 — — — 14,626 Other Deposits with no stated maturity (a) 93,588 — 93,588 — — — 93,588 Valuation Methods and Assumptions (a) Fair value equals or approximates carrying amount. The fair value of deposits with no stated maturity does not take into consideration the value ascribed to core deposit intangibles. (b) Information pertaining to our methodology for measuring the fair values of these assets and liabilities is included in the sections entitled “Qualitative Disclosures of Valuation Techniques” and “Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis” in this Note. Investments accounted for under the cost method (or cost less impairment adjusted for observable price changes for certain equity investments) are classified as Level 3 assets. These investments are not actively traded in an open market as sales for these types of investments are rare. The carrying amount of the investments carried at cost are adjusted for declines in value if they are considered to be other-than-temporary (or due to observable orderly transactions of the same issuer for equity investments eligible for the cost less impairment measurement alternative). These adjustments are included in “other income” on the income statement. (c) Fair values of held-to-maturity securities are determined by using models that are based on security-specific details, as well as relevant industry and economic factors. The most significant of these inputs are quoted market prices, interest rate spreads on relevant benchmark securities, and certain prepayment assumptions. We review the valuations derived from the models to ensure that they are reasonable and consistent with the values placed on similar securities traded in the secondary markets. (d) The fair value of loans is based on the present value of the expected cash flows. The projected cash flows are based on the contractual terms of the loans, adjusted for prepayments and use of a discount rate based on the relative risk of the cash flows, taking into account the loan type, maturity of the loan, liquidity risk, servicing costs, and a required return on debt and capital. In addition, an incremental liquidity discount is applied to certain loans, using historical sales of loans during periods of similar economic conditions as a benchmark. The fair value of loans includes lease financing receivables at their aggregate carrying amount, which is equivalent to their fair value. (e) Fair values of time deposits and long-term debt are based on discounted cash flows utilizing relevant market inputs. (f) Netting adjustments represent the amounts recorded to convert our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. The net basis takes into account the impact of bilateral collateral and master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Total derivative assets and liabilities include these netting adjustments. (g) Derivative assets-hedging and derivative liabilities-hedging includes both cash flow and fair value hedges. Additional information regarding our accounting policies for cash flow and fair value hedges is provided in Note 1 (“ Summary of Significant Accounting Policies

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Details of Securities	2018 2017 December 31, in millions Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value SECURITIES AVAILABLE FOR SALE U.S. Treasury, Agencies, and Corporations $ 150 — $ 3 $ 147 $ 159 — $ 2 $ 157 States and political subdivisions 7 — — 7 9 — — 9 Agency residential collateralized mortgage obligations 14,315 $ 20 373 13,962 14,985 $ 10 335 14,660 Agency residential mortgage-backed securities 2,128 13 36 2,105 1,456 3 20 1,439 Agency commercial mortgage-backed securities 3,300 19 132 3,187 1,920 — 66 1,854 Other securities 17 3 — 20 17 3 — 20 Total securities available for sale $ 19,917 $ 55 $ 544 $ 19,428 $ 18,546 $ 16 $ 423 $ 18,139 HELD-TO-MATURITY SECURITIES Agency residential collateralized mortgage obligations $ 7,021 2 $ 254 $ 6,769 $ 8,055 — $ 224 $ 7,831 Agency residential mortgage-backed securities 490 $ — 14 476 574 $ 1 4 571 Agency commercial mortgage-backed securities 3,996 2 133 3,865 3,186 6 44 3,148 Other securities 12 — — 12 15 — — 15 Total held-to-maturity securities $ 11,519 $ 4 $ 401 $ 11,122 $ 11,830 $ 7 $ 272 $ 11,565
Schedule of Unrealized Loss on Investments	The following table summarizes our securities that were in an unrealized loss position as of December 31, 2018 , and December 31, 2017 : Duration of Unrealized Loss Position Less than 12 Months 12 Months or Longer Total in millions Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses December 31, 2018 Securities available for sale: U.S. Treasury, Agencies, and Corporations — — $ 147 $ 3 $ 147 $ 3 Agency residential collateralized mortgage obligations $ 570 $ 2 10,945 371 11,515 373 Agency residential mortgage-backed securities 4 — (a) 1,087 36 1,091 36 Agency commercial mortgage-backed securities — — 1,729 132 1,729 132 Held-to-maturity securities: Agency residential collateralized mortgage obligations — — 6,416 254 6,416 254 Agency residential mortgage-backed securities — — 475 14 475 14 Agency commercial mortgage-backed securities 73 — (a) 3,359 133 3,432 133 Other securities — — — — — — Total temporarily impaired securities $ 647 $ 2 $ 24,158 $ 943 $ 24,805 $ 945 December 31, 2017 Securities available for sale: U.S. Treasury, Agencies, and Corporations $ 41 — (b) 116 $ 2 $ 157 $ 2 Agency residential collateralized mortgage obligations 6,153 $ 74 $ 7,270 261 13,423 335 Agency residential mortgage-backed securities 666 7 702 13 1,368 20 Agency commercial mortgage-backed securities 205 4 1,649 62 1,854 66 Held-to-maturity securities: Agency residential collateralized mortgage obligations 2,201 27 5,599 197 7,800 224 Agency residential mortgage-backed securities 252 1 206 3 458 4 Agency commercial mortgage-backed securities 1,470 12 495 32 1,965 44 Other securities 3 — (b) 4 — (b) 7 — Total temporarily impaired securities $ 10,991 $ 125 $ 16,041 $ 570 $ 27,032 $ 695 (a) At December 31, 2018 , gross unrealized losses totaled less than $1 million for agency residential mortgage-backed securities available for sale with a loss duration of less than 12 months and less than $1 million for agency commercial mortgage-backed securities held-to-maturity with a loss duration of less than 12 months. (b) At December 31, 2017 , gross unrealized losses totaled less than $1 million for U.S. Treasury, Agencies, and Corporations available for sale with a loss duration of less than 12 months and less than $1 million for other securities held-to-maturity with a loss duration of less than and greater than 12 months.
Debt Securities, Available-for-sale	Realized gains and losses related to securities available for sale were as follows: Year ended December 31, in millions 2018 (a) 2017 (b) 2016 (a) Realized gains — $ 1 — Realized losses — — — Net securities gains (losses) — $ 1 — (a) Realized losses totaled less than $1 million for the year ended December 31, 2018 , and December 31, 2016 . (b) Realized losses totaled less than $1 million for the year ended December 31, 2017
Securities by Maturity	The following table shows securities by remaining maturity. CMOs and other mortgage-backed securities in the available-for-sale and held-to-maturity portfolios are presented based on their expected average lives. The remaining securities, in both the available-for-sale and held-to-maturity portfolios, are presented based on their remaining contractual maturity. Actual maturities may differ from expected or contractual maturities since borrowers have the right to prepay obligations with or without prepayment penalties. Securities Available for Sale Held-to-Maturity Securities December 31, 2018 Amortized Cost Fair Value Amortized Cost Fair Value in millions Due in one year or less $ 116 $ 116 $ 36 $ 36 Due after one through five years 12,298 11,949 6,402 6,210 Due after five through ten years 7,492 7,352 5,081 4,876 Due after ten years 11 11 — — Total $ 19,917 $ 19,428 $ 11,519 $ 11,122

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Values, Volume of Activity and Gain (Loss) Information Related to Derivative Instruments	The following table summarizes the fair values of our derivative instruments on a gross and net basis as of December 31, 2018 , and December 31, 2017 . The change in the notional amounts of these derivatives by type from December 31, 2017 , to December 31, 2018 , indicates the volume of our derivative transaction activity during 2018 . The notional amounts are not affected by bilateral collateral and master netting agreements. The derivative asset and liability balances are presented on a gross basis, prior to the application of bilateral collateral and master netting agreements. Total derivative assets and liabilities are adjusted to take into account the impact of legally enforceable master netting agreements that allow us to settle all derivative contracts with a single counterparty on a net basis and to offset the net derivative position with the related cash collateral. Where master netting agreements are not in effect or are not enforceable under bankruptcy laws, we do not adjust those derivative assets and liabilities with counterparties. Securities collateral related to legally enforceable master netting agreements is not offset on the balance sheet. Our derivative instruments are included in “accrued income and other assets” or “accrued expenses and other liabilities” on the balance sheet, as indicated in the following table: December 31, 2018 December 31, 2017 Fair Value Fair Value in millions Notional Amount Derivative Assets Derivative Liabilities Notional Amount Derivative Assets Derivative Liabilities Derivatives designated as hedging instruments: Interest rate $ 28,546 $ 50 $ (10 ) $ 26,176 $ 81 $ 46 Foreign exchange 122 2 — 302 1 4 Total 28,668 52 (10 ) 26,478 82 50 Derivatives not designated as hedging instruments: Interest rate 63,454 365 307 61,390 641 474 Foreign exchange 6,829 104 95 8,317 129 120 Commodity 2,002 333 323 1,687 255 246 Credit 226 1 1 315 1 4 Other (a) 1,466 9 7 2,006 4 13 Total 73,977 812 733 73,715 1,030 857 Netting adjustments (b) — (333 ) (337 ) — (443 ) (616 ) Net derivatives in the balance sheet 102,645 531 386 100,193 669 291 Other collateral (c) — (2 ) (33 ) — (5 ) (84 ) Net derivative amounts $ 102,645 $ 529 $ 353 $ 100,193 $ 664 $ 207 (a) Other derivatives include interest rate lock commitments and forward sale commitments related to our residential mortgage banking activities, forward purchase and sales contracts consisting of contractual commitments associated with “to be announced” securities and when issued securities, and when-issued security transactions in connection with an “at-the-market” equity offering program. (b) Netting adjustments represent the amounts recorded to convert our derivative assets and liabilities from a gross basis to a net basis in accordance with the applicable accounting guidance. (c)
Pre-Tax Net Gains (Losses) on Fair Value Hedges	The following table summarizes the amounts that were recorded on the balance sheet as of December 31, 2018 , related to cumulative basis adjustments for fair value hedges. December 31, 2018 in millions Balance sheet line item in which the hedge item is included Carrying amount of hedged item (a) Hedge accounting basis adjustment (b) Interest rate contracts Long-term debt $ 9,363 $ (6 ) Interest rate contracts Certificate of deposit ($100,000 or more) 343 (1 ) Interest rate contracts Other time deposits 178 — (a) The carrying amount represents the portion of the liability designated as the hedged item. (b) Basis adjustment includes $10 million related to de-designated hedged items no longer in qualifying fair value hedging relationships.
Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location	The following tables summarize the effect of fair value and cash flow hedge accounting on the income statement for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 . Location and amount of net gains (losses) recognized in income on fair value and cash flow hedging relationships (a) in millions Interest expense – long-term debt Interest income – loans Investment banking and debt placement fees Interest expense – deposits Other income Year ended December 31, 2018 Total amounts presented in the consolidated statement of income $ (420 ) $ 4,023 $ 650 $ (517 ) $ 176 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items (5 ) — — 1 — Recognized on derivatives designated as hedging instruments (12 ) — — — — Net income (expense) recognized on fair value hedges (17 ) — — 1 — Net gain (loss) on cash flow hedging relationships Interest contracts Realized gains (losses) (pre-tax) reclassified from AOCI into net income (2 ) (68 ) 2 — 31 Net income (expense) recognized on cash flow hedges $ (2 ) $ (68 ) $ 2 — 31 Year ended December 31, 2017 Total amounts presented in the consolidated statement of income $ (319 ) $ 3,677 $ 603 $ (278 ) $ 153 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items — — — — 107 Recognized on derivatives designated as hedging instruments 49 — — — (103 ) Net income (expense) recognized on fair value hedges $ 49 — — — $ 4 Net gain (loss) on cash flow hedging relationships Interest contracts Realized gains (losses) (pre-tax) reclassified from AOCI into net income $ (4 ) $ 19 — — — Gains (losses) (before tax) recognized in income for hedge ineffectiveness — — — — — Net income (expense) recognized on cash flow hedges $ (4 ) $ 19 $ — — — Year ended December 31, 2016 Total amounts presented in the consolidated statement of income $ (218 ) $ 2,773 $ 482 $ (171 ) $ 114 Net gains (losses) on fair value hedging relationships Interest contracts Recognized on hedged items — — — — 97 Recognized on derivatives designated as hedging instruments 96 — — — (95 ) Net income (expense) recognized on fair value hedges 96 — — — 2 Net gain (loss) on cash flow hedging relationships Interest contracts Realized gains (losses) (pre-tax) reclassified from AOCI into net income (4 ) 85 — — — Gains (losses) (before tax) recognized in income for hedge ineffectiveness — — — — — Net income (expense) recognized on cash flow hedges $ (4 ) $ 85 $ — — — (a) Prior period gain or loss amounts were not restated to conform to the new hedge accounting guidance adopted in 2018.
Derivative Instrument Cash Flow Hedge Earning Recognized by Income Statement Location	The following table summarizes the pre-tax net gains (losses) on our cash flow and net investment hedges for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 , and where they are recorded on the income statement. The table includes net gains (losses) recognized in OCI during the period and net gains (losses) reclassified from OCI into income during the current period. in millions Net Gains (Losses) Recognized in OCI Income Statement Location of Net Gains (Losses) Reclassified From OCI Into Income Net Gains (Losses) Reclassified From OCI Into Income (a) Net Gains (Losses) Recognized in Other Income (a) Year ended December 31, 2018 Cash Flow Hedges Interest rate $ (13 ) Interest income — Loans $ (68 ) $ — Interest rate 2 Interest expense — Long-term debt (2 ) — Interest rate 1 Investment banking and debt placement fees 2 — Net Investment Hedges Foreign exchange contracts 19 Other Income 31 — Total $ 9 $ (37 ) $ — Year ended December 31, 2017 Cash Flow Hedges Interest rate $ (59 ) Interest income — Loans $ 19 $ — Interest rate — Interest expense — Long-term debt (4 ) — Interest rate (1 ) Investment banking and debt placement fees — — Net Investment Hedges Foreign exchange contracts (17 ) Other Income — — Total $ (77 ) $ 15 $ — Year ended December 31, 2016 Cash Flow Hedges Interest rate $ 29 Interest income — Loans $ 85 $ — Interest rate — Interest expense — Long-term debt (4 ) — Interest rate 1 Investment banking and debt placement fees — — Net Investment Hedges Foreign exchange contracts (2 ) Other Income — — Total $ 28 $ 81 $ — (a)
Pre-Tax Net Gains (Losses) on Derivatives Not Designated as Hedging Instruments	The following table summarizes the pre-tax net gains (losses) on our derivatives that are not designated as hedging instruments for the years ended December 31, 2018 , December 31, 2017 , and December 31, 2016 , and where they are recorded on the income statement. 2018 2017 2016 Year ended December 31, in millions Corporate Services Income Consumer Mortgage Income Other Income Total Corporate Services Income Consumer Mortgage Income Other Income Total Corporate Services Income Consumer Mortgage Income Other Income Total NET GAINS (LOSSES) Interest rate $ 38 — $ (1 ) $ 37 $ 29 — $ (1 ) $ 28 $ 30 — $ 1 $ 31 Foreign exchange 42 — — 42 41 — — 41 40 — — 40 Commodity 8 — — 8 6 — — 6 4 — — 4 Credit 2 — (30 ) (28 ) 2 — (21 ) (19 ) 1 — (16 ) (15 ) Other — $ (1 ) 12 11 — $ (1 ) (6 ) (7 ) — $ 1 — 1 Total net gains (losses) $ 90 $ (1 ) $ (19 ) $ 70 $ 78 $ (1 ) $ (28 ) $ 49 $ 75 $ 1 $ (15 ) $ 61
Fair Value of Derivative Assets by Type	The following table summarizes the fair value of our derivative assets by type at the dates indicated. These assets represent our gross exposure to potential loss after taking into account the effects of bilateral collateral and master netting agreements and other means used to mitigate risk. December 31, in millions 2018 2017 Interest rate $ 308 $ 401 Foreign exchange 60 77 Commodity 187 163 Credit — 1 Other 9 4 Derivative assets before collateral 564 646 Less: Related collateral 33 (23 ) Total derivative assets $ 531 $ 669
Credit Derivatives Sold and Held	The following table provides information on the types of credit derivatives sold by us and held on the balance sheet at December 31, 2018 , and December 31, 2017 . The notional amount represents the maximum amount that the seller could be required to pay. The payment/performance risk assessment is based on the default probabilities for the underlying reference entities’ debt obligations using a Moody’s credit ratings matrix known as Moody’s “Idealized” Cumulative Default Rates. The payment/performance risk shown in the table represents a weighted-average of the default probabilities for all reference entities in the respective portfolios. These default probabilities are directly correlated to the probability that we will have to make a payment under the credit derivative contracts. 2018 2017 December 31, dollars in millions Notional Amount Average Term (Years) Payment / Performance Risk Notional Amount Average Term (Years) Payment / Performance Risk Other $ 22 13.43 17.18 % $ 15 3.08 6.64 % Total credit derivatives sold $ 22 — — $ 15 — —
Credit Risk Contingent Feature	The following table summarizes the additional cash and securities collateral that KeyBank would have been required to deliver under the ISDA Master Agreements had the credit risk contingent features been triggered for the derivative contracts in a net liability position as of December 31, 2018 , and December 31, 2017 . The additional collateral amounts were calculated based on scenarios under which KeyBank’s ratings are downgraded one, two, or three ratings as of December 31, 2018 , and December 31, 2017 , and take into account all collateral already posted. A similar calculation was performed for KeyCorp, and no additional collateral would have been required at December 31, 2018 , or December 31, 2017 . December 31, in millions 2018 2017 Moody’s S&P Moody’s S&P KeyBank’s long-term senior unsecured credit ratings A3 A- A3 A- One rating downgrade $ 2 $ 2 $ 2 $ 2 Two rating downgrades 2 2 2 2 Three rating downgrades 2 2 2 2

Mortgage Servicing Assets (Tabl

Mortgage Servicing Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Servicing Asset [Abstract]
Changes in Carrying Amount of Mortgage Servicing Assets	Changes in the carrying amount of residential mortgage servicing assets are summarized as follows: in millions 2018 2017 Balance at beginning of period $ 31 28 Servicing retained from loan sales 10 $ 7 Purchases — — Amortization (4 ) (4 ) Balance at end of period $ 37 $ 31 Fair value at end of period $ 52 $ 37 Year ended December 31, in millions 2018 2017 Balance at beginning of period $ 412 $ 356 Servicing retained from loan sales 117 110 Purchases 75 36 Amortization (102 ) (90 ) Balance at end of period $ 502 $ 412 Fair value at end of period $ 757 $ 537
Schedule of Range and Weighted-Average of Significant Unobservable Inputs	The range and weighted-average of the significant unobservable inputs used to fair value our residential mortgage servicing assets at December 31, 2018 , along with the valuation techniques, are shown in the following table: December 31, 2018 December 31, 2017 Valuation Technique Significant Unobservable Input Range (Weighted-Average) Discounted cash flow Prepayment speed 8.45 - 56.11% (9.08%) 9.16 - 51.52% (10.46%) Discount rate 7.50 - 10.00% (7.54%) 8.50 - 11.00% (8.54%) Servicing cost $62 - $5,125 ($68.25) $76 - $4,385 ($83.11) December 31, 2018 , and December 31, 2017 , along with the valuation techniques, are shown in the following table: dollars in millions December 31, 2018 December 31, 2017 Valuation Technique Significant Unobservable Input Range (Weighted-Average) Discounted cash flow Expected defaults 1.00 - 2.00% (1.14%) 1.00 - 3.00% (1.20%) Residual cash flows discount rate 7.00 - 15.00% (9.18%) 7.00 - 15.00% (9.10%) Escrow earn rate 2.56 - 4.20% (3.35%) .90 - 3.10% (2.50%) Loan assumption rate 0.00 - 3.22% (1.35%) 0.00 - 3.00% (1.22%)

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Premises and equipment at December 31, 2018 , and December 31, 2017 , consisted of the following: December 31, dollars in millions Useful life (in years) 2018 2017 Land Indefinite $ 135 $ 138 Buildings and improvements 15-40 747 741 Leasehold improvements 1-15 626 633 Furniture and equipment 2-15 907 931 Capitalized building leases 1-14 (a) 28 27 Construction in process N/A 35 38 Total premises and equipment 2,478 2,508 Less: Accumulated depreciation and amortization (1,596 ) (1,578 ) Premises and equipment, net $ 882 $ 930 (a)

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill	Changes in the carrying amount of goodwill by reporting unit are presented in the following table: in millions Key Community Bank Key Corporate Bank Total BALANCE AT DECEMBER 31, 2016 $ 2,088 $ 358 $ 2,446 Fair value measurement adjustments - First Niagara acquisition 15 3 18 Additional ownership interest in Key Merchant Services 4 — 4 Acquisition of HelloWallet 17 — 17 Acquisition of Cain Brothers — 53 53 BALANCE AT DECEMBER 31, 2017 2,124 414 2,538 KIBS divestiture (22 ) — (22 ) BALANCE AT DECEMBER 31, 2018 $ 2,102 $ 414 $ 2,516
Gross Carrying Amount and Accumulated Amortization of Intangible Assets	The following table shows the gross carrying amount and the accumulated amortization of intangible assets subject to amortization: 2018 2017 December 31, in millions Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Intangible assets subject to amortization: Core deposit intangibles $ 396 $ 184 $ 461 $ 192 PCCR intangibles 152 138 152 126 Other intangible assets 115 25 128 7 Total $ 663 $ 347 $ 741 $ 325
Schedule of Acquired Finite-Lived Intangible Assets by Major Class	Intangible assets acquired during the year ended December 31, 2017, were as follows: in millions KMS HelloWallet Cain Brothers Total Intangible assets subject to amortization: Customer relationships $ 85 — $ 29 $ 114 Trade name — — 1 1 Proprietary software — $ 12 — 12 Total $ 85 $ 12 $ 30 $ 127
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table presents estimated intangible asset amortization expense for the next five years. Estimated in millions 2019 2020 2021 2022 2023 Intangible asset amortization expense $ 80 $ 62 $ 52 $ 42 $ 34

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Variable Interest Entities Information	The assets and liabilities presented in the table below convey the size of KCDC’s direct and indirect investments at December 31, 2018 , and December 31, 2017 . As these investments represent unconsolidated VIEs, the assets and liabilities of the investments themselves are not recorded on our balance sheet. Unconsolidated VIEs in millions Total Assets Total Liabilities Maximum Exposure to Loss December 31, 2018 LIHTC investments $ 5,932 $ 2,569 $ 1,740 December 31, 2017 LIHTC investments $ 6,003 $ 2,943 $ 1,561 December 31, 2018 . Unconsolidated VIEs in millions Total Assets Total Liabilities Maximum Exposure to Loss December 31, 2018 Indirect investments $ 19,659 $ 376 $ 122 December 31, 2017 Indirect investments $ 26,817 $ 292 $ 153

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes Included in Income Statement	Income taxes included in the income statement are summarized below. We file a consolidated federal income tax return. Year ended December 31, in millions 2018 2017 2016 Currently payable: Federal $ 184 $ 334 $ 149 State 62 — 19 Total currently payable 246 334 168 Deferred: Federal 117 274 13 State (19 ) 29 (2 ) Total deferred 98 303 11 Total income tax (benefit) expense (a) $ 344 $ 637 $ 179 (a) There was no income tax (benefit) expense on securities transactions in 2018 , 2017 , and 2016 . Income tax expense excludes equity- and gross receipts-based taxes, which are assessed in lieu of an income tax in certain states in which we operate. These taxes, which are recorded in “noninterest expense” on the income statement, totaled $15 million in 2018 , $22 million in 2017 , and $18 million in 2016 .
Significant Components of Deferred Tax Assets and Liabilities Included in "Accrued Income and Other Assets" and "Accrued Expense and Other Liabilities"	Significant components of our deferred tax assets and liabilities included in “accrued income and other assets” and “accrued expense and other liabilities,” respectively, on the balance sheet, are as follows: December 31, in millions 2018 2017 Allowance for loan and lease losses $ 232 $ 233 Employee benefits 170 147 Net unrealized securities losses 144 138 Federal net operating losses and credits 34 205 Fair value adjustments 41 63 Non-tax accruals 80 89 State net operating losses and credits 3 7 Other 221 223 Gross deferred tax assets 925 1,105 Less: Valuation Allowance 11 15 Total deferred tax assets 914 1,090 Leasing transactions 531 588 Other 161 182 Total deferred tax liabilities 692 770 Net deferred tax assets (liabilities) (a) $ 222 $ 320 (a)
Total Income Tax Expense (Benefit) and Resulting Effective Tax Rate	The following table shows how our total income tax expense (benefit) and the resulting effective tax rate were derived: Year ended December 31, dollars in millions 2018 2017 2016 Amount Rate Amount Rate Amount Rate Income (loss) before income taxes times 21% (35% for 2017 and 2016) statutory federal tax rate $ 463 21.0 % $ 675 35.0 % $ 339 35.0 % Amortization of tax-advantaged investments 127 5.8 104 5.4 88 9.0 Foreign tax adjustments 2 .1 1 .1 1 .1 Tax-exempt interest income (30 ) (1.4 ) (37 ) (1.9 ) (25 ) (2.6 ) Corporate-owned life insurance income (29 ) (1.3 ) (46 ) (2.4 ) (44 ) (4.5 ) State income tax, net of federal tax benefit 34 1.5 19 1.0 11 1.1 Tax credits (234 ) (10.6 ) (218 ) (11.3 ) (208 ) (21.3 ) Tax Cuts and Jobs Act 7 .3 147 7.6 — — Other 4 .2 (8 ) (.5 ) 17 1.7 Total income tax expense (benefit) $ 344 15.6 % $ 637 33.0 % $ 179 18.5 %
Change in Liability for Unrecognized Tax Benefits	The change in our liability for unrecognized tax benefits is as follows: Year ended December 31, 2018 2017 Balance at beginning of year $ 39 $ 53 Increase for other tax positions of prior years 15 3 Increase from Acquisitions — 3 Decrease for payments and settlements — (4 ) Decrease related to tax positions taken in prior years (19 ) (16 ) Balance at end of year $ 35 $ 39

Securities Financing Activiti_2

Securities Financing Activities (Tables)	12 Months Ended
	Dec. 31, 2018
Brokers and Dealers [Abstract]
Summarized Securities Financing Agreements	The following table summarizes our securities financing agreements at December 31, 2018 , and December 31, 2017 : December 31, 2018 December 31, 2017 in millions Gross Amount Presented in Balance Sheet Netting Adjustments (a) Collateral (b) Net Amounts Gross Amount Presented in Balance Sheet Netting Adjustments (a) Collateral (b) Net Amounts Offsetting of financial assets: Reverse repurchase agreements $ 14 $ (14 ) $ — — $ 3 $ (3 ) — — Total $ 14 $ (14 ) $ — — $ 3 $ (3 ) — — Offsetting of financial liabilities: Repurchase agreements (c) $ 319 $ (14 ) $ (305 ) — $ 374 $ (4 ) $ (370 ) — Total $ 319 $ (14 ) $ (305 ) — $ 374 $ (4 ) $ (370 ) — (a) Netting adjustments take into account the impact of master netting agreements that allow us to settle with a single counterparty on a net basis. (b) These adjustments take into account the impact of bilateral collateral agreements that allow us to offset the net positions with the related collateral. The application of collateral cannot reduce the net position below zero. Therefore, excess collateral, if any, is not reflected above. (c)

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Assumptions Used in Options Pricing Model	The assumptions pertaining to options issued during 2018 , 2017 , and 2016 are shown in the following table. Year ended December 31, 2018 2017 2016 Average option life 6.5 years 6.0 years 6.0 years Future dividend yield 2.28 % 1.79 % 2.86 % Historical share price volatility .282 .287 .297 Weighted-average risk-free interest rate 2.8 % 2.1 % 1.3 %
Activity, Pricing and Other Information for Stock Options	The following table summarizes activity, pricing and other information for our stock options for the year ended December 31, 2018 : Number of Options Weighted-Average Exercise Price Per Option Weighted-Average Remaining Life Aggregate Intrinsic Value (a) Outstanding at December 31, 2017 9,882,617 $ 11.28 5.5 years $ 88 Granted 346,088 21.02 Exercised (1,960,444 ) 10.12 Lapsed or canceled (144,417 ) 14.37 Outstanding at December 31, 2018 8,123,844 $ 11.92 5.3 31 Expected to vest 2,508,684 15.09 7.6 5 Exercisable at December 31, 2018 5,479,638 $ 10.36 4.2 $ 26 (a) The intrinsic value of a stock option is the amount by which the fair value of the underlying stock exceeds the exercise price of the option.
Activity and Pricing Information for Nonvested Shares in Long-Term Incentive Compensation Program	The following table summarizes activity and pricing information for the nonvested shares in the Program for the year ended December 31, 2018 . Vesting Contingent on Service Conditions Vesting Contingent on Performance and Service Conditions Number of Nonvested Shares Weighted- Average Grant-Date Fair Value Number of Nonvested Shares Weighted- Average Grant-Date Fair Value Outstanding at December 31, 2017 11,832,956 $ 14.05 4,148,020 $ 17.51 Granted 4,076,746 21.02 1,588,738 14.83 Vested (5,404,616 ) 13.61 (1,070,112 ) 17.73 Forfeited (930,136 ) 17.01 (127,191 ) 19.42 Outstanding at December 31, 2018 9,574,950 $ 16.84 4,539,455 $ 14.35
Activity and Pricing Information for Nonvested Shares Granted Under Deferred Compensation Plans and Other Restricted Stock Awards	The following table summarizes activity and pricing information for the nonvested shares granted under our deferred compensation plans and these other restricted stock or unit award programs for the year ended December 31, 2018 . Number of Nonvested Shares Weighted-Average Grant-Date Fair Value Outstanding at December 31, 2017 4,223,774 $ 15.61 Granted 724,287 20.77 Dividend equivalents 18 20.03 Vested (1,523,387 ) 14.43 Forfeited (144,875 ) 14.18 Outstanding at December 31, 2018 3,279,817 $ 17.36

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
Net Pension Cost and Amount Recognized in OCI for All Funded and Unfunded Plans	The components of net pension cost and the amount recognized in OCI for all funded and unfunded plans are as follows: Year ended December 31, in millions 2018 2017 2016 Interest cost on PBO $ 41 $ 48 $ 44 Expected return on plan assets (53 ) (68 ) (58 ) Amortization of losses 17 15 17 Settlement loss 17 — 18 Net pension cost $ 22 $ (5 ) $ 21 Other changes in plan assets and benefit obligations recognized in OCI: Net (gain) loss $ 20 $ (10 ) $ (9 ) Amortization of gains (33 ) (15 ) (35 ) Total recognized in comprehensive income $ (13 ) $ (25 ) $ (44 ) Total recognized in net pension cost and comprehensive income $ 9 $ (30 ) $ (23 )
Changes in PBO Related to Pension Plans	The following table summarizes changes in the PBO related to our pension plans. Year ended December 31, in millions 2018 2017 PBO at beginning of year $ 1,323 $ 1,338 Interest cost 41 48 Actuarial losses (gains) (66 ) 37 Benefit payments (97 ) (100 ) PBO at end of year $ 1,201 $ 1,323
Changes in FVA	The following table summarizes changes in the FVA. Year ended December 31, in millions 2018 2017 FVA at beginning of year $ 1,163 $ 1,133 Actual return on plan assets (34 ) 115 Employer contributions 14 15 Benefit payments (97 ) (100 ) FVA at end of year $ 1,046 $ 1,163
Funded Status of Pension Plans Recognized in Balance Sheets	The following table summarizes the funded status of the pension plans, which equals the amounts recognized in the balance sheets at December 31, 2018 , and December 31, 2017 . December 31, in millions 2018 2017 Funded status (a) $ (155 ) $ (160 ) Net prepaid pension cost recognized consists of: Noncurrent assets $ 17 29 Current liabilities (15 ) $ (15 ) Noncurrent liabilities (157 ) (174 ) Net prepaid pension cost recognized (b) $ (155 ) $ (160 ) (a) The shortage of the FVA under the PBO. (b)
Plans ABO in Excess of Plan Assets	As indicated in the table below, collectively our plans had an ABO in excess of plan assets as follows: December 31, in millions 2018 2017 PBO $ 1,201 $ 1,323 ABO 1,201 1,323 Fair value of plan assets 1,046 1,163
Weighted-Average Rates to Determine Actuarial Present Value of Benefit Obligations	To determine the actuarial present value of benefit obligations, we assumed the following weighted-average rates. December 31, 2018 2017 Discount rate 4.00 % 3.25 % Compensation increase rate N/A N/A
Weighted-Average Rates to Determine Net Pension Cost	To determine net pension cost, we assumed the following weighted-average rates. Year ended December 31, 2018 2017 2016 Discount rate 3.25 % 3.75 % 3.75 % Compensation increase rate N/A N/A N/A Expected return on plan assets 4.75 6.00 6.00
Asset Target Allocations Prescribed by Pension Funds' Investment Policies	The following table shows the asset target allocations prescribed by the pension fund’s investment policies based on the plan’s funded status at December 31, 2018 . Target Allocation Asset Class 2018 Equity securities: U.S. 5 % International 4 Fixed income securities 81 Real assets 6 Other assets 4 Total 100 %
Fair Values of Pension Plan Assets by Asset Category	The following tables show the fair values of our pension plan assets by asset class at December 31, 2018 , and December 31, 2017 . December 31, 2018 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Equity securities: Common — U.S. $ 6 — — $ 6 Preferred — U.S. 3 — — 3 Debt securities: Corporate bonds — U.S. — $ 157 — 157 Corporate bonds — International — 65 — 65 Government and agency bonds — U.S. — 180 — 180 Government bonds — International — 2 — 2 State and municipal bonds — 28 — 28 Mutual funds: Equity — International 1 — — 1 Collective investment funds (measured at NAV) (a) — — — 546 Insurance investment contracts and pooled separate accounts (measured at NAV) (a) — — — 16 Other assets (measured at NAV) (a) — — — 42 Total net assets at fair value $ 10 $ 432 — $ 1,046 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. December 31, 2017 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Equity securities: Common — U.S. 11 — — 11 Common — International 1 — — 1 Preferred — U.S. 3 — — 3 Debt securities: Corporate bonds — U.S. — $ 152 — 152 Corporate bonds — International — 61 — 61 Government and agency bonds — U.S. — 203 — 203 Government bonds — International — 2 — 2 State and municipal bonds — 31 — 31 Mutual funds: Equity — International 7 — — 7 Collective investment funds (measured at NAV) (a) — — — 628 Insurance investment contracts and pooled separate accounts (measured at NAV) (a) — — — 14 Other assets (measured at NAV) (a) — — — 50 Total net assets at fair value $ 22 $ 449 — $ 1,163 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote.
Pre-tax AOCI Not Yet Recognized as Net Postretirement Benefit Cost	The components of pre-tax AOCI not yet recognized as net postretirement benefit cost are shown below. December 31, in millions 2018 2017 Net unrecognized losses (gains) $ (12 ) $ (12 ) Net unrecognized prior service credit — (1 ) Total unrecognized AOCI $ (12 ) $ (13 )
Net Postretirement Benefit Cost and Amount Recognized in OCI for All Funded and Unfunded Plans	The components of net postretirement benefit cost and the amount recognized in OCI for all funded and unfunded plans are as follows: December 31, in millions 2018 2017 2016 Service cost of benefits earned $ 1 $ 1 $ 1 Interest cost on APBO 2 3 2 Expected return on plan assets (2 ) (2 ) (2 ) Amortization of prior service credit (1 ) (1 ) (1 ) Amortization of gains (1 ) — — Net postretirement benefit $ (1 ) 1 — Other changes in plan assets and benefit obligations recognized in OCI: Net (gain) loss $ 1 $ (4 ) $ (4 ) Amortization of prior service credit 1 1 1 Amortization of losses — — — Total recognized in comprehensive income $ 2 $ (3 ) $ (3 ) Total recognized in net postretirement benefit cost and comprehensive income $ 1 $ (2 ) $ (3 )
Changes in APBO	The following table summarizes changes in the APBO. Year ended December 31, in millions 2018 2017 APBO at beginning of year $ 69 $ 69 Service cost 1 1 Interest cost 2 3 Plan participants’ contributions 1 1 Actuarial losses (gains) (6 ) 3 Benefit payments (4 ) (8 ) APBO at end of year $ 63 $ 69
Change in FVA (Other Post Retirement Benefit Plan Assets)	The following table summarizes changes in FVA. Year ended December 31, in millions 2018 2017 FVA at beginning of year $ 52 $ 50 Employer contributions — — Plan participants’ contributions 1 1 Benefit payments (4 ) (8 ) Actual return on plan assets (2 ) 9 FVA at end of year $ 47 $ 52
Funded Status of Postretirement Plans Recognized in Balance Sheets	The following table summarizes the funded status of the postretirement plans, which corresponds to the amounts recognized in the balance sheets at December 31, 2018 , and December 31, 2017 . December 31, in millions 2018 2017 Funded status (a) $ (17 ) $ (16 ) Accrued postretirement benefit cost recognized (b) (17 ) (16 ) (a) The shortage of the FVA under the APBO. (b)
Weighted-Average Rates to Determine Net Postretirement Benefit Cost	To determine net postretirement benefit cost, we assumed the following weighted-average rates. Year ended December 31, 2018 2017 2016 Discount rate 3.50 % 3.75 % 4.00 % Expected return on plan assets 4.50 4.50 4.50
Asset Target Allocations Prescribed by Trusts' Investment Policies	The following table shows the asset target allocations prescribed by the trust’s investment policy. Target Allocation Asset Class 2018 Equity securities 80 % Fixed income securities 20 Cash equivalents — Total 100 %
Fair Values of Pension Plan Assets by Asset Category	The following tables show the fair values of our postretirement plan assets by asset class at December 31, 2018 , and December 31, 2017 . December 31, 2018 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Mutual funds: Equity — U.S. $ 21 — — $ 21 Equity — International 8 — — 8 Fixed income — U.S. 7 — — 7 Collective investment funds: Equity — U.S. (a) — — — 9 Other assets (measured at NAV) (a) — — — 2 Total net assets at fair value $ 36 — — $ 47 (a) Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the fair value of plan assets presented elsewhere within this footnote. December 31, 2017 in millions Level 1 Level 2 Level 3 Total ASSET CLASS Mutual funds: Equity — U.S. $ 25 — — $ 25 Equity — International 10 — — 10 Fixed income — U.S. 4 — — 4 Fixed income — International 3 — — 3 Collective investment funds: Equity — U.S. (a) — $ — — 10 Total net assets at fair value $ 42 $ — — $ 52 (a)

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Components of Short-Term Borrowings	Selected financial information pertaining to the components of our short-term borrowings is as follows: December 31, dollars in millions 2018 2017 2016 FEDERAL FUNDS PURCHASED Balance at year end — $ 3 $ 1,005 Average during the year $ 537 128 44 Maximum month-end balance 3,197 2,331 1,005 Weighted-average rate during the year (a) 1.68 % .72 % .68 % Weighted-average rate at December 31 (a) — — .55 SECURITIES SOLD UNDER REPURCHASE AGREEMENTS Balance at year end $ 319 $ 374 $ 497 Average during the year 391 389 443 Maximum month-end balance 614 472 684 Weighted-average rate during the year (a) .09 % .08 % .04 % Weighted-average rate at December 31 (a) .09 .08 .07 OTHER SHORT-TERM BORROWINGS Balance at year end $ 544 $ 634 $ 808 Average during the year 915 1,140 852 Maximum month-end balance 1,133 1,242 872 Weighted-average rate during the year (a) 2.34 % 1.34 % 1.18 % Weighted-average rate at December 31 (a) 2.92 2.01 1.11 (a) Rates exclude the effects of interest rate swaps and caps, which modify the repricing characteristics of certain short-term borrowings. For more information about such financial instruments, see Note 8 (“ Derivatives and Hedging Activities

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Components of Long-Term Debt	The following table presents the components of our long-term debt, net of unamortized discounts and adjustments related to hedging with derivative financial instruments. We use interest rate swaps and caps, which modify the repricing characteristics of certain long-term debt, to manage interest rate risk. For more information about such financial instruments, see Note 8 (“ Derivatives and Hedging Activities ”). December 31, dollars in millions 2018 2017 Senior medium-term notes due through 2021 (a) $ 3,278 $ 2,766 3.136% Subordinated notes due 2028 (b) 162 161 6.875% Subordinated notes due 2029 (b) 104 109 7.75% Subordinated notes due 2029 (b) 135 141 7.25% Subordinated notes due 2021 (c) 336 348 6.75% Senior notes due 2020 (d) 315 327 Other subordinated notes (b), (e) 70 69 Total parent company 4,400 3,921 Senior medium-term notes due through 2039 (f) 7,022 8,011 3.18% Senior remarketable notes due 2027 (g) 212 202 4.625% Subordinated notes due 2018 (h) — 100 3.40% Subordinated notes due 2026 (h) 560 565 6.95% Subordinated notes due 2028 (h) 299 299 Secured borrowing due through 2025 (i) 10 24 Federal Home Loan Bank advances due through 2038 (j) 1,130 1,106 Investment Fund Financing due through 2052 (k) 83 88 Obligations under Capital Leases due through 2032 (l) 16 17 Total subsidiaries 9,332 10,412 Total long-term debt $ 13,732 $ 14,333 (a) Senior medium-term notes had a weighted-average interest rate of 4.057% at December 31, 2018 , and 3.56% at December 31, 2017 . These notes had fixed interest rates at December 31, 2018 , and December 31, 2017 . These notes may not be redeemed prior to their maturity dates. (b) See Note 20 (“ Trust Preferred Securities Issued by Unconsolidated Subsidiaries ”) for a description of these notes. (c) The First Niagara subordinated debt had a weighted-average interest rate of 7.25% at December 31, 2018 , and a weighted-average interest rate of 7.25% at December 31, 2017 . These notes may not be redeemed prior to their maturity dates. (d) The First Niagara senior notes had a weighted-average interest rate of 6.75% at December 31, 2018 , and a weighted-average interest rate of 6.75% at December 31, 2017 . These notes may not be redeemed prior to their maturity dates. (e) The First Niagara variable rate trust preferred securities had a weighted-average interest rate of 4.20% at December 31, 2018 , and 3.022% at December 31, 2017 . These notes may be redeemed prior to their maturity dates. (f) Senior medium-term notes had weighted-average interest rates of 2.593% at December 31, 2018 , and 2.24% at December 31, 2017 . These notes are a combination of fixed and floating rates. These notes may not be redeemed prior to their maturity dates. (g) The remarketable senior medium-term notes had a weighted-average interest rate of 3.18% at December 31, 2018 , and 3.18% at December 31, 2017 . These notes had fixed interest rates at December 31, 2017, and December 31, 2018. These notes may not be redeemed prior to their maturity dates. (h) These notes are all obligations of KeyBank and may not be redeemed prior to their maturity dates. (i) The secured borrowing had weighted-average interest rates of 4.455% at December 31, 2018 , and 4.460% at December 31, 2017 . This borrowing is collateralized by commercial lease financing receivables, and principal reductions are based on the cash payments received from the related receivables. Additional information pertaining to these commercial lease financing receivables is included in Note 4 (“ Loan Portfolio ”). (j) Long-term advances from the Federal Home Loan Bank had a weighted-average interest rate of 2.333% at December 31, 2018 , and 2.318% at December 31, 2017 . These advances, which had fixed interest rates, were secured by real estate loans and securities totaling $1.1 billion at December 31, 2018 , and $1.1 billion at December 31, 2017 . (k) Investment Fund Financing had a weighted-average interest rate of 1.85% at December 31, 2018 , and 1.94% at December 31, 2017 . (l) These are capital leases acquired in the First Niagara merger with a maturity range from June 2019 through October 2032.
Scheduled Principal Payments on Long-Term Debt	At December 31, 2018 , scheduled principal payments on long-term debt were as follows: in millions Parent Subsidiaries Total 2019 — $ 2,262 $ 2,262 2020 $ 1,298 1,396 2,694 2021 1,350 1,744 3,094 2022 — 1,469 1,469 2023 — 456 456 All subsequent years 1,752 2,005 3,757

Trust Preferred Securities Is_2

Trust Preferred Securities Issued by Unconsolidated Subsidiaries (Tables)	12 Months Ended
	Dec. 31, 2018
Banking and Thrift [Abstract]
Summary of Trust Preferred Securities, Common Stock and Related Debentures	The trust preferred securities, common stock, and related debentures are summarized as follows: dollars in millions Trust Preferred Securities, Net of Discount (a) Common Stock Principal Amount of Debentures, Net of Discount (b) Interest Rate of Trust Preferred Securities and (c) Maturity of Trust Preferred Securities and Debentures December 31, 2018 KeyCorp Capital I $ 156 $ 6 $ 162 3.136 % 2028 KeyCorp Capital II 100 4 104 6.875 2029 KeyCorp Capital III 131 4 135 7.750 2029 HNC Statutory Trust III 19 1 20 4.053 2035 Willow Grove Statutory Trust I 18 1 19 4.098 2036 HNC Statutory Trust IV 16 1 17 3.800 2037 Westbank Capital Trust II 7 — 7 4.982 2034 Westbank Capital Trust III 7 — 7 4.982 2034 Total $ 454 $ 17 $ 471 5.447 % — December 31, 2017 $ 463 $ 17 $ 480 4.977 % — (a) The trust preferred securities must be redeemed when the related debentures mature, or earlier if provided in the governing indenture. Each issue of trust preferred securities carries an interest rate identical to that of the related debenture. Certain trust preferred securities include basis adjustments related to fair value hedges totaling $46 million at December 31, 2018 , and $55 million at December 31, 2017 . See Note 8 (“Derivatives and Hedging Activities”) for an explanation of fair value hedges. (b) We have the right to redeem these debentures. If the debentures purchased by KeyCorp Capital I, HNC Statutory Trust III, Willow Grove Statutory Trust I, HNC Statutory Trust IV, Westbank Capital Trust II, or Westbank Capital Trust III are redeemed before they mature, the redemption price will be the principal amount, plus any accrued but unpaid interest. If the debentures purchased by KeyCorp Capital II or KeyCorp Capital III are redeemed before they mature, the redemption price will be the greater of: (i) the principal amount, plus any accrued but unpaid interest, or (ii) the sum of the present values of principal and interest payments discounted at the Treasury Rate (as defined in the applicable indenture), plus 20 basis points for KeyCorp Capital II or 25 basis points for KeyCorp Capital III or 50 basis points in the case of redemption upon either a tax or a capital treatment event for either KeyCorp Capital II or KeyCorp Capital III, plus any accrued but unpaid interest. The principal amount of certain debentures includes basis adjustments related to fair value hedges totaling $46 million at December 31, 2018 , and $55 million at December 31, 2017 . See Note 8 for an explanation of fair value hedges. The principal amount of debentures, net of discounts, is included in “long-term debt” on the balance sheet. (c) The interest rates for the trust preferred securities issued by KeyCorp Capital II and KeyCorp Capital III are fixed. The trust preferred securities issued by KeyCorp Capital I have a floating interest rate, equal to three-month LIBOR plus 74 basis points, that reprices quarterly. The trust preferred securities issued by HNC Statutory Trust III have a floating interest rate, equal to three-month LIBOR plus 140 basis points, that reprices quarterly. The trust preferred securities issued by Willow Grove Statutory Trust I have a floating interest rate, equal to three-month LIBOR plus 131 basis points, that reprices quarterly. The trust preferred securities issued by HNC Statutory Trust IV have a floating interest rate, equal to three-month LIBOR plus 128 basis points, that reprices quarterly. The trust preferred securities issued by Westbank Capital Trust II and Westbank Capital Trust III each have a floating interest rate, equal to three-month LIBOR plus 219

Commitments, Contingent Liabi_2

Commitments, Contingent Liabilities and Guarantees (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments to Extend Credit or Funding	The following table shows the remaining contractual amount of each class of commitment related to extending credit or funding principal investments as of December 31, 2018 , and December 31, 2017 . For loan commitments and commercial letters of credit, this amount represents our maximum possible accounting loss on the unused commitment if the borrower were to draw upon the full amount of the commitment and subsequently default on payment for the total amount of the then outstanding loan. December 31, in millions 2018 2017 Loan commitments: Commercial and other $ 42,653 $ 40,315 Commercial real estate and construction 2,691 2,774 Home equity 9,982 9,673 Credit cards 6,152 5,890 Total loan commitments 61,478 58,652 Commercial letters of credit 86 231 Purchase card commitments 621 425 Principal investing commitments 26 29 Tax credit investment commitments 520 481 Securities underwriting — 9 Total loan and other commitments $ 62,731 $ 59,827
Guarantees	The following table shows the types of guarantees that we had outstanding at December 31, 2018 . Information pertaining to the basis for determining the liabilities recorded in connection with these guarantees is included in Note 1 (“ Summary of Significant Accounting Policies ”) under the heading “Guarantees.” December 31, 2018 Maximum Potential Undiscounted Future Payments Liability Recorded in millions Financial guarantees: Standby letters of credit $ 3,137 $ 72 Recourse agreement with FNMA 4,082 6 Residential mortgage reserve 1,549 6 Return guarantee agreement with LIHTC investors 2 2 Written put options (a) 2,345 88 Total $ 11,115 $ 174 (a)

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Changes in AOCI	Our changes in AOCI for the years ended December 31, 2018 , and December 31, 2017 , are as follows: in millions Unrealized gains (losses) on securities available for sale Unrealized gains (losses) on derivative financial instruments Foreign currency translation adjustment Net pension and postretirement benefit costs Total Balance at December 31, 2016 $ (185 ) $ (14 ) $ (3 ) $ (339 ) $ (541 ) Other comprehensive income before reclassification, net of income taxes (69 ) (48 ) 12 9 (96 ) Amounts reclassified from accumulated other comprehensive income, net of income taxes (a) (1 ) (10 ) 1 9 (1 ) Amounts reclassified from accumulated other comprehensive income resulting from new federal corporate income tax rate (b) (56 ) (14 ) (1 ) (70 ) (141 ) Net current-period other comprehensive income, net of income taxes (126 ) (72 ) 12 (52 ) (238 ) Balance at December 31, 2017 $ (311 ) $ (86 ) $ 9 $ (391 ) $ (779 ) Other comprehensive income before reclassification, net of income taxes (62 ) 7 (10 ) (15 ) (80 ) Amounts reclassified from accumulated other comprehensive income, net of income taxes (a) — 29 — 25 54 Other amounts reclassified from AOCI, net of income taxes — — (13 ) — (13 ) Net current-period other comprehensive income, net of income taxes (62 ) 36 (23 ) 10 (39 ) Balance at December 31, 2018 $ (373 ) $ (50 ) $ (14 ) $ (381 ) $ (818 ) (a) See table below for details about these reclassifications. (b)
Reclassifications Out of AOCI	Our reclassifications out of AOCI for the years ended December 31, 2018 , and December 31, 2017 , are as follows: Twelve months ended December 31, Affected Line Item in the Statement Where Net Income is Presented in millions 2018 2017 Unrealized gains (losses) on available for sale securities Realized gains — $ 1 Other income Realized losses — — Other income — 1 Income (loss) from continuing operations before income taxes — — Income taxes — $ 1 Income (loss) from continuing operations Unrealized gains (losses) on derivative financial instruments Interest rate $ (68 ) $ 19 Interest income — Loans Interest rate (2 ) (4 ) Interest expense — Long-term debt Interest rate 2 — Investment banking and debt placement fees Foreign exchange contracts 31 — Other income (37 ) 15 Income (loss) from continuing operations before income taxes (8 ) 5 Income taxes $ (29 ) $ 10 Income (loss) from continuing operations Foreign currency translation adjustment — $ (1 ) Corporate services income — (1 ) Income (loss) from continuing operations before income taxes — — Income taxes — $ (1 ) Income (loss) from continuing operations Net pension and postretirement benefit costs Amortization of losses $ (17 ) $ (15 ) Personnel expense Settlement loss (17 ) — Personnel expense Amortization of prior service credit 1 1 Personnel expense (33 ) (14 ) Income (loss) from continuing operations before income taxes (8 ) (5 ) Income taxes $ (25 ) $ (9 ) Income (loss) from continuing operations

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Key's and KeyBank's Actual Capital Amounts and Ratios, Minimum Capital Amounts and Ratios	At December 31, 2018 , Key and KeyBank (consolidated) had regulatory capital in excess of all current minimum risk-based capital (including all adjustments for market risk) and leverage ratio requirements as shown in the following table. Actual To Meet Minimum Capital Adequacy Requirements To Qualify as Well Capitalized Under Federal Deposit Insurance Act dollars in millions Amount Ratio Amount Ratio Amount Ratio December 31, 2018 TOTAL CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 15,953 12.89 % $ 9,903 8.00 % N/A N/A KeyBank (consolidated) 15,432 12.68 9,733 8.00 $ 12,166 10.00 % TIER 1 CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 13,712 11.08 % $ 7,427 6.00 % N/A N/A KeyBank (consolidated) 13,575 11.16 7,300 6.00 $ 7,300 6.00 % TIER 1 CAPITAL TO AVERAGE QUARTERLY TANGIBLE ASSETS Key $ 13,712 9.89 % $ 5,548 4.00 % N/A N/A KeyBank (consolidated) 13,575 9.93 5,470 4.00 $ 6,838 5.00 % December 31, 2017 TOTAL CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 15,345 12.92 % $ 9,505 8.00 % N/A N/A KeyBank (consolidated) 14,957 12.86 9,306 8.00 $ 11,633 10.00 % TIER 1 CAPITAL TO NET RISK-WEIGHTED ASSETS Key $ 13,083 11.01 % $ 7,129 6.00 % N/A N/A KeyBank (consolidated) 13,110 11.27 6,980 6.00 $ 6,980 6.00 % TIER 1 CAPITAL TO AVERAGE QUARTERLY TANGIBLE ASSETS Key $ 13,083 9.73 % $ 5,379 4.00 % N/A N/A KeyBank (consolidated) 13,110 9.91 5,293 4.00 $ 6,617 5.00 %
Schedule of Stockholders Equity	The following table summarizes our preferred stock at December 31, 2018 : Preferred stock series Amount outstanding (in millions) Shares authorized and outstanding Par value Liquidation preference Ownership interest per depositary share Liquidation preference per depositary share 2018 dividends paid per depositary share Fixed-to-Floating Rate Perpetual Noncumulative Series D $ 525 21,000 $ 1 $ 25,000 1/25th $ 1,000 $ 50.00 Fixed-to-Floating Rate Perpetual Noncumulative Series E 500 500,000 1 1,000 1/40th 25 1.531252 Fixed Rate Perpetual Noncumulative Series F 425 425,000 1 1,000 1/40th 25 .529688

Line of Business Results (Table

Line of Business Results (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Financial Information of Business Groups	Year ended December 31, Key Community Bank Key Corporate Bank dollars in millions 2018 2017 2016 2018 2017 2016 SUMMARY OF OPERATIONS Net interest income (TE) $ 2,873 $ 2,652 $ 1,953 $ 1,094 $ 1,193 $ 1,049 Noninterest income 1,098 1,143 906 1,161 1,148 1,013 Total revenue (TE) (a) 3,971 3,795 2,859 2,255 2,341 2,062 Provision for credit losses 177 209 143 74 20 127 Depreciation and amortization expense 110 116 76 135 96 60 Other noninterest expense 2,451 2,424 2,048 1,147 1,158 1,073 Income (loss) from continuing operations before income taxes (TE) 1,233 1,046 592 899 1,067 802 Allocated income taxes (benefit) and TE adjustments 291 388 220 110 249 178 Income (loss) from continuing operations 942 658 372 789 818 624 Income (loss) from discontinued operations, net of taxes — — — — — — Net income (loss) 942 658 372 789 818 624 Less: Net income (loss) attributable to noncontrolling interests — — — — — (2 ) Net income (loss) attributable to Key $ 942 $ 658 $ 372 $ 789 $ 818 $ 626 AVERAGE BALANCES (b) Loans and leases $ 47,877 $ 47,399 $ 37,624 $ 39,536 $ 37,716 $ 31,925 Total assets (a) 51,774 51,370 40,300 47,126 44,505 37,797 Deposits 81,868 79,669 63,875 21,183 21,318 20,780 OTHER FINANCIAL DATA Expenditures for additions to long-lived assets (a), (b) $ 2,352 $ 2,438 $ 1,478 $ 538 $ 559 $ 340 Net loan charge-offs (b) 161 166 114 73 40 83 Return on average allocated equity (b) 19.50 % 13.71 % 10.96 % 27.01 % 28.82 % 26.89 % Return on average allocated equity 19.50 13.71 10.96 27.01 28.82 26.89 Average full-time equivalent employees (c) 10,501 10,587 8,794 2,528 2,407 2,244 (a) Substantially all revenue generated by our major business segments is derived from clients that reside in the United States. Substantially all long-lived assets, including premises and equipment, capitalized software, and goodwill held by our major business segments, are located in the United States. (b) From continuing operations. (c) The number of average full-time equivalent employees was not adjusted for discontinued operations. Other Segments Total Segments Reconciling Items Key 2018 2017 2016 2018 2017 2016 2018 2017 2016 2018 2017 2016 $ (55 ) $ (35 ) $ (45 ) $ 3,912 $ 3,810 $ 2,957 $ 28 $ 20 $ (4 ) $ 3,940 $ 3,830 $ 2,953 206 208 170 2,465 2,499 2,089 50 (21 ) (18 ) 2,515 2,478 2,071 151 173 125 6,377 6,309 5,046 78 (1 ) (22 ) 6,455 6,308 5,024 (5 ) — (4 ) 246 229 266 — — — 246 229 266 1 3 4 246 215 140 154 169 163 400 384 303 53 101 61 3,651 3,683 3,182 (76 ) 31 271 3,575 3,714 3,453 102 69 64 2,234 2,182 1,458 — (201 ) (456 ) 2,234 1,981 1,002 (8 ) (48 ) (22 ) 393 589 376 (18 ) 101 (163 ) 375 690 213 110 117 86 1,841 1,593 1,082 18 (302 ) (293 ) 1,859 1,291 789 — — — — — — 7 7 1 7 7 1 110 117 86 1,841 1,593 1,082 25 (295 ) (292 ) 1,866 1,298 790 — 3 2 — 3 — — (1 ) (1 ) — 2 (1 ) $ 110 $ 114 $ 84 $ 1,841 $ 1,590 $ 1,082 $ 25 $ (294 ) $ (291 ) $ 1,866 $ 1,296 $ 791 $ 916 $ 1,225 $ 1,486 $ 88,329 $ 86,340 $ 71,035 $ 9 $ 25 $ 113 $ 88,338 $ 86,365 $ 71,148 37,551 37,158 31,938 136,451 133,033 110,035 361 686 2,502 136,812 133,719 112,537 1,956 1,988 1,213 105,007 102,975 85,868 44 (29 ) 484 105,051 102,946 86,352 $ 10 19 — $ 2,900 $ 3,016 $ 1,818 $ 101 $ 81 $ 116 $ 3,001 $ 3,097 $ 1,934 (1 ) $ 1 $ 7 233 207 204 1 1 1 234 208 205 88.00 % 73.55 % 48.84 % 23.37 % 20.41 % 18.36 % .25 % (4.05 )% (4.32 )% 12.29 % 8.47 % 6.25 % 88.00 73.55 48.84 23.37 20.41 18.36 .34 (3.96 ) (4.31 ) 12.33 8.51 6.25 130 338 147 13,159 13,332 11,185 5,021 5,083 4,515 18,180 18,415 15,700

Condensed Financial Informati_2

Condensed Financial Information of the Parent Company (Tables)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheets	CONDENSED BALANCE SHEETS December 31, in millions 2018 2017 ASSETS Cash and due from banks $ 3,241 $ 2,257 Short-term investments 19 22 Securities available for sale 10 10 Other investments 31 29 Loans to: Banks 50 250 Nonbank subsidiaries 31 31 Total loans 81 281 Investment in subsidiaries: Banks 15,554 15,169 Nonbank subsidiaries 833 885 Total investment in subsidiaries 16,387 16,054 Goodwill 167 167 Corporate-owned life insurance 199 208 Derivative assets 61 29 Accrued income and other assets 279 353 Total assets $ 20,475 $ 19,410 LIABILITIES Accrued expense and other liabilities $ 480 $ 466 Long-term debt due to: Subsidiaries 471 480 Unaffiliated companies 3,929 3,441 Total long-term debt 4,400 3,921 Total liabilities 4,880 4,387 SHAREHOLDERS’ EQUITY (a) 15,595 15,023 Total liabilities and shareholders’ equity $ 20,475 $ 19,410 (a)
Condensed Statements of Income	CONDENSED STATEMENTS OF INCOME Year ended December 31, in millions 2018 2017 2016 INCOME Dividends from subsidiaries: Bank subsidiaries $ 1,675 $ 750 $ 625 Nonbank subsidiaries — — 50 Interest income from subsidiaries 11 10 10 Other income 11 9 11 Total income 1,697 769 696 EXPENSE Interest on long-term debt with subsidiary trusts 20 17 14 Interest on other borrowed funds 137 95 69 Personnel and other expense 69 46 101 Total expense 226 158 184 Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries 1,471 611 512 Income tax (expense) benefit 55 29 54 Income (loss) before equity in net income (loss) less dividends from subsidiaries 1,526 640 566 Equity in net income (loss) less dividends from subsidiaries 340 658 224 NET INCOME (LOSS) 1,866 1,298 790 Less: Net income attributable to noncontrolling interests — 2 (1 ) NET INCOME (LOSS) ATTRIBUTABLE TO KEY $ 1,866 $ 1,296 $ 791 .
Condensed Statements of Cash Flows	CONDENSED STATEMENTS OF CASH FLOWS Year ended December 31, in millions 2018 2017 2016 OPERATING ACTIVITIES Net income (loss) attributable to Key $ 1,866 $ 1,296 $ 791 Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities: Deferred income taxes (benefit) 109 38 (24 ) Stock-based compensation expense 8 11 12 Equity in net (income) loss less dividends from subsidiaries (340 ) (658 ) (224 ) Other intangible asset amortization — — — Net (increase) decrease in goodwill and other intangibles — — — Net (increase) decrease in other assets (58 ) 82 (93 ) Net increase (decrease) in other liabilities 8 (82 ) 9 Other operating activities, net 79 (114 ) — NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES 1,672 573 471 INVESTING ACTIVITIES Net (increase) decrease in securities available for sale and in short-term and other investments 1 47 (17 ) Cash infusion from purchase of Cain Brothers — (90 ) — Cash used in acquisitions — — (481 ) Proceeds from sales, prepayments and maturities of securities available for sale — 1 — Net (increase) decrease in loans to subsidiaries 200 — 160 NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES 201 (42 ) (338 ) FINANCING ACTIVITIES Net proceeds from issuance of long-term debt 1,250 — — Payments on long-term debt (750 ) — (21 ) Repurchase of Treasury Shares (1,145 ) (730 ) (140 ) Net cash from the issuance (redemption) of Common Shares and preferred stock 412 (350 ) 1,041 Cash dividends paid (656 ) (480 ) (335 ) NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES (889 ) (1,560 ) 545 NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS 984 (1,029 ) 678 CASH AND DUE FROM BANKS AT BEGINNING OF YEAR 2,257 3,286 2,608 CASH AND DUE FROM BANKS AT END OF YEAR $ 3,241 $ 2,257 $ 3,286

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table represents a disaggregation of revenue from contracts with customers, by line of business, for the twelve months ended December 31, 2018 : Twelve months ended December 31, 2018 dollars in millions Key Community Bank Key Corporate Bank Total Contract Revenue NONINTEREST INCOME Trust and investment services income $ 358 $ 69 $ 427 Investment banking and debt placement fees 5 255 260 Services charges on deposit accounts 310 52 362 Cards and payments income 155 108 263 Other noninterest income 18 — 18 Total revenue from contracts with customers $ 846 $ 484 $ 1,330 Other noninterest income (a) $ 929 Noninterest income from other segments (b) 206 Reconciling items (c) 50 Total noninterest income $ 2,515 (a) Noninterest income considered earned outside the scope of contracts with customers. (b) Other Segments consist of corporate treasury, our principal investing unit, and various exit portfolios. (c)

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2018USD ($)SegmentstateATMBranch	Jan. 01, 2019USD ($)
Accounting Policies [Line Items]
Number of retail branches | Branch	1,159
Number of automated teller machines | ATM	1,505
Number of states with automated teller machines | state	15
Number of business groups | Segment	2
Number of days to designate the loan as nonaccrual for commercial loan payment due period	90 days
Number of days to designate commercial loans will be charged off in full or charged down to the fair value of the underlying collateral payment due period	180 days
Number of days to designate the loan as nonaccrual for consumer payment due period	120 days
Second lien home equity loan with associated first lien due period	120 days
Number of days to designate the charge-off policy for most consumer loans taking effect, payment due period	120 days
Number of days to designate home equity and residential mortgage loans to get charged down to the fair value of the underlying collateral payment due period	180 days
Number of days to designate charge-off policy for credit card loans and similar unsecured products taking effect, payment due period	180 days
Threshold period by which amortized cost is greater than fair value to be considered as other-than-temporary	6 months
Minimum outstanding impaired commercial loans	$ 2,500,000
Minimum percentage for an input to be significant of the total fair value of a particular asset or liability	10.00%
Maximum limit for vary of market related value	10.00%
Amortization period of stock-based compensation awards	5 years
Vesting period for compensation cost	4 years
Minimum future rental payments under noncancelable operating leases	$ 908,000,000
Stock Options [Member]
Accounting Policies [Line Items]
Options expiration years	10 years
Stock Options [Member] | One year after the grant date [Member]
Accounting Policies [Line Items]
Rate at which employee stock options granted to be exercisable	25.00%
Maximum [Member]
Accounting Policies [Line Items]
Nonperforming loans, collectively evaluated for impairment	$ 2,500,000
Maximum [Member] | Stock Options [Member]
Accounting Policies [Line Items]
Options expiration years	10 years
Scenario, Forecast [Member] | Accounting Standards Update 2016-02 [Member]
Accounting Policies [Line Items]
Operating lease, right-of-use assets		$ 700,000,000
Operating lease, lease liabilities		$ 700,000,000

Earnings Per Common Share - Bas

Earnings Per Common Share - Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
EARNINGS
Income (loss) from continuing operations		$ 1,859	$ 1,291	$ 789
Less: Net income (loss) attributable to noncontrolling interests		0	2	(1)
Income (loss) from continuing operations attributable to Key		1,859	1,289	790
Less: Dividends on preferred stock		66	70	37
Income (loss) from continuing operations attributable to Key common shareholders		1,793	1,219	753
Income (loss) from discontinued operations, net of taxes		7	7	1
Net income (loss) attributable to Key common shareholders		$ 1,800	$ 1,226	$ 754
WEIGHTED-AVERAGE COMMON SHARES
Weighted-average common shares outstanding (in shares)		1,040,890	1,072,078	927,816
Effect of common share options and other stock awards (in shares)		13,792	16,515	10,720
Weighted-average common shares and potential common shares outstanding (000) (in shares)	[1]	1,054,682	1,088,593	938,536
EARNINGS PER COMMON SHARE
Income (loss) from continuing operations attributable to Key common shareholders (in dollars per share)		$ 1.72	$ 1.13	$ 0.81
Income (loss) from discontinued operations, net of taxes (in dollars per share)		0.01	0.01	0
Net income (loss) attributable to Key common shareholders (in dollars per share)	[2]	1.73	1.14	0.81
Income (loss) from continuing operations attributable to Key common shareholders - assuming dilution (in dollars per share)		1.70	1.12	0.80
Income (loss) from discontinued operations, net of taxes (in dollars per share)		0.01	0.01	0
Net income (loss) attributable to Key common shareholders (in dollars per share)	[2]	$ 1.71	$ 1.13	$ 0.80
[1]	Assumes conversion of Common Share options and other stock awards and/or convertible preferred stock, as applicable.
[2]	EPS may not foot due to rounding.

Restrictions on Cash, Dividen_2

Restrictions on Cash, Dividends and Lending Activities - Narrative (Details) - USD ($) $ in Millions	Jan. 01, 2019	Dec. 31, 2018
Restricted Cash and Cash Equivalents Items [Line Items]
Average reserve balance maintained		$ 363
Short-term investments held for discharge of obligations		3,300
KeyBank (consolidated) [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Dividends paid by non banking subsidiaries		$ 1,700
KeyBank (consolidated) [Member] | Subsequent Event [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Capacity to pay dividends	$ 1,000

Loan Portfolio - Loans by Categ

Loan Portfolio - Loans by Category (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Residential — prime loans:
Total Loans	$ 89,552	$ 86,405
Collateral for secured borrowings	10	24
Net loans	88,669	85,528
Commercial Credit Card [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial, financial and agricultural	132	119
Discontinued Operations [Member] | Education Lending [Member]
Residential — prime loans:
Net loans	1,100	1,300
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial, financial and agricultural	45,753	41,859
Commercial real estate:
Commercial mortgage	14,285	14,088
Construction	1,666	1,960
Total commercial real estate loans	15,951	16,048
Commercial lease financing	4,606	4,826
Total loans	66,310	62,733
Residential — prime loans:
Total Loans	66,310	62,733
Consumer Loans [Member]
Commercial real estate:
Total loans	23,242	23,672
Residential — prime loans:
Real estate — residential mortgage	5,513	5,483
Home equity loans	11,142	12,028
Total residential — prime loans	16,655	17,511
Consumer direct loans	1,809	1,794
Credit cards	1,144	1,106
Consumer indirect loans	3,634	3,261
Total Loans	$ 23,242	$ 23,672

Loan Portfolio - Composition of

Loan Portfolio - Composition of Net Investment in Direct Financing Leases (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Loans Receivables [Abstract]
Direct financing lease receivables	$ 3,658	$ 3,727
Unearned income	(345)	(323)
Unguaranteed residual value	412	382
Deferred fees and costs	19	19
Net investment in direct financing leases	$ 3,744	$ 3,805

Loan Portfolio - Narrative (Det

Loan Portfolio - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Minimum future lease payment to be received, 2019	$ 1,000
Minimum future lease payment to be received, 2020	878
Minimum future lease payment to be received, 2021	609
Minimum future lease payment to be received, 2022	399
Minimum future lease payment to be received, 2023	238
Minimum future lease payment to be received, subsequent years	416
Allowance related to lease financing receivables	897	$ 893	$ 882	$ 824
Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to lease financing receivables	883	877	858	796
Continuing Operations [Member] | Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to lease financing receivables	743	735	716	656
Continuing Operations [Member] | Commercial Loans [Member] | Commercial Lease Financing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance related to lease financing receivables	$ 36	$ 43	$ 42	$ 47

Asset Quality - Financing Recei

Asset Quality - Financing Receivable Credit Quality Indicators (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 89,552	$ 86,405
Commercial Portfolio Segment Excluding PCI Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	66,069	62,376
Commercial Portfolio Segment Excluding PCI Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	63,904	59,785
Commercial Portfolio Segment Excluding PCI Loans [Member] | Criticized Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,922	2,400
Commercial Portfolio Segment Excluding PCI Loans [Member] | Criticized Nonaccruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	243	191
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	45,692	41,776
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial, Financial and Agricultural [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	44,138	39,833
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial, Financial and Agricultural [Member] | Criticized Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,402	1,790
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial, Financial and Agricultural [Member] | Criticized Nonaccruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	152	153
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	14,107	13,840
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial Real Estate Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	13,672	13,328
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial Real Estate Loans [Member] | Criticized Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	354	482
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial Real Estate Loans [Member] | Criticized Nonaccruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	81	30
Commercial Portfolio Segment Excluding PCI Loans [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,664	1,934
Commercial Portfolio Segment Excluding PCI Loans [Member] | Construction Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,537	1,894
Commercial Portfolio Segment Excluding PCI Loans [Member] | Construction Loans [Member] | Criticized Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	125	38
Commercial Portfolio Segment Excluding PCI Loans [Member] | Construction Loans [Member] | Criticized Nonaccruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2	2
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,606	4,826
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial Leases [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,557	4,730
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial Leases [Member] | Criticized Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	41	90
Commercial Portfolio Segment Excluding PCI Loans [Member] | Commercial Leases [Member] | Criticized Nonaccruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	8	6
Consumer Portfolio Segment Excluding PCI [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	22,908	23,291
Consumer Portfolio Segment Excluding PCI [Member] | FICO Score, 750 and Above [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	12,511	12,694
Consumer Portfolio Segment Excluding PCI [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	7,433	7,563
Consumer Portfolio Segment Excluding PCI [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2,316	2,394
Consumer Portfolio Segment Excluding PCI [Member] | FICO Score, No Score [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	648	640
Consumer Portfolio Segment Excluding PCI [Member] | Residential Prime Financing Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	16,324	17,134
Consumer Portfolio Segment Excluding PCI [Member] | Residential Prime Financing Receivables [Member] | FICO Score, 750 and Above [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,794	10,226
Consumer Portfolio Segment Excluding PCI [Member] | Residential Prime Financing Receivables [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	4,906	5,181
Consumer Portfolio Segment Excluding PCI [Member] | Residential Prime Financing Receivables [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,411	1,519
Consumer Portfolio Segment Excluding PCI [Member] | Residential Prime Financing Receivables [Member] | FICO Score, No Score [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	213	208
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Direct Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,806	1,790
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Direct Loans [Member] | FICO Score, 750 and Above [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	549	519
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Direct Loans [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	700	690
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Direct Loans [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	224	225
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Direct Loans [Member] | FICO Score, No Score [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	333	356
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Credit Card [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,144	1,106
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Credit Card [Member] | FICO Score, 750 and Above [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	521	477
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Credit Card [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	507	508
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Credit Card [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	116	121
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Credit Card [Member] | FICO Score, No Score [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3,634	3,261
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Indirect Loans [Member] | FICO Score, 750 and Above [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,647	1,472
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Indirect Loans [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1,320	1,184
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Indirect Loans [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	565	529
Consumer Portfolio Segment Excluding PCI [Member] | Consumer Indirect Loans [Member] | FICO Score, No Score [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	102	76
Commercial Portfolio Segment, PCI [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	241	357
Commercial Portfolio Segment, PCI [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	164	220
Commercial Portfolio Segment, PCI [Member] | Criticized Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	77	137
Commercial Portfolio Segment, PCI [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	61	83
Commercial Portfolio Segment, PCI [Member] | Commercial, Financial and Agricultural [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	37	41
Commercial Portfolio Segment, PCI [Member] | Commercial, Financial and Agricultural [Member] | Criticized Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	24	42
Commercial Portfolio Segment, PCI [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	178	248
Commercial Portfolio Segment, PCI [Member] | Commercial Real Estate Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	125	153
Commercial Portfolio Segment, PCI [Member] | Commercial Real Estate Loans [Member] | Criticized Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	53	95
Commercial Portfolio Segment, PCI [Member] | Construction Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2	26
Commercial Portfolio Segment, PCI [Member] | Construction Loans [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2	26
Commercial Portfolio Segment, PCI [Member] | Construction Loans [Member] | Criticized Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Commercial Portfolio Segment, PCI [Member] | Commercial Leases [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Commercial Portfolio Segment, PCI [Member] | Commercial Leases [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Commercial Portfolio Segment, PCI [Member] | Commercial Leases [Member] | Criticized Accruing [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	334	381
Consumer Portfolio Segment, PCI [Member] | FICO Score, 750 and Above [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	137	149
Consumer Portfolio Segment, PCI [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	96	119
Consumer Portfolio Segment, PCI [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	99	107
Consumer Portfolio Segment, PCI [Member] | FICO Score, No Score [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2	6
Consumer Portfolio Segment, PCI [Member] | Residential Prime Financing Receivables [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	331	377
Consumer Portfolio Segment, PCI [Member] | Residential Prime Financing Receivables [Member] | FICO Score, 750 and Above [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	137	149
Consumer Portfolio Segment, PCI [Member] | Residential Prime Financing Receivables [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	95	117
Consumer Portfolio Segment, PCI [Member] | Residential Prime Financing Receivables [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	97	105
Consumer Portfolio Segment, PCI [Member] | Residential Prime Financing Receivables [Member] | FICO Score, No Score [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2	6
Consumer Portfolio Segment, PCI [Member] | Consumer Direct Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	3	4
Consumer Portfolio Segment, PCI [Member] | Consumer Direct Loans [Member] | FICO Score, 750 and Above [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Direct Loans [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	1	2
Consumer Portfolio Segment, PCI [Member] | Consumer Direct Loans [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	2	2
Consumer Portfolio Segment, PCI [Member] | Consumer Direct Loans [Member] | FICO Score, No Score [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Credit Card [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Credit Card [Member] | FICO Score, 750 and Above [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Credit Card [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Credit Card [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Credit Card [Member] | FICO Score, No Score [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Indirect Loans [Member] | FICO Score, 750 and Above [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Indirect Loans [Member] | FICO Score, 660 to 749 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Indirect Loans [Member] | FICO Score, Less than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	0	0
Consumer Portfolio Segment, PCI [Member] | Consumer Indirect Loans [Member] | FICO Score, No Score [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 0	$ 0

Asset Quality - Aging Analysis

Asset Quality - Aging Analysis of Past Due and Current Loans (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 88,011	$ 84,716
Total Past Due and Non-performing Loans	966	951
Non-performing Loans	542	503
Purchased Credit Impaired	575	738
Total Loans	89,552	86,405
Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	218	261
Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	94	98
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	112	89
Commercial Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	65,558	61,904
Total Past Due and Non-performing Loans	511	472
Non-performing Loans	244	191
Purchased Credit Impaired	241	357
Total Loans	66,310	62,733
Commercial Loans [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	45,375	41,444
Total Past Due and Non-performing Loans	317	332
Non-performing Loans	152	153
Purchased Credit Impaired	61	83
Total Loans	45,753	41,859
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	13,957	13,750
Total Past Due and Non-performing Loans	150	90
Non-performing Loans	81	30
Purchased Credit Impaired	178	248
Total Loans	14,285	14,088
Commercial Loans [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,646	1,919
Total Past Due and Non-performing Loans	18	15
Non-performing Loans	2	2
Purchased Credit Impaired	2	26
Total Loans	1,666	1,960
Commercial Loans [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	15,603	15,669
Total Past Due and Non-performing Loans	168	105
Non-performing Loans	83	32
Purchased Credit Impaired	180	274
Total Loans	15,951	16,048
Commercial Loans [Member] | Commercial Lease Financing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	4,580	4,791
Total Past Due and Non-performing Loans	26	35
Non-performing Loans	9	6
Purchased Credit Impaired	0	0
Total Loans	4,606	4,826
Commercial Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	128	164
Commercial Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	89	111
Commercial Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	27	26
Commercial Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	0	4
Commercial Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	27	30
Commercial Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Lease Financing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	12	23
Commercial Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	62	60
Commercial Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	31	34
Commercial Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	17	13
Commercial Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	13	9
Commercial Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	30	22
Commercial Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Lease Financing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	1	4
Commercial Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	77	57
Commercial Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	45	34
Commercial Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	25	21
Commercial Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	3	0
Commercial Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	28	21
Commercial Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Lease Financing [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	4	2
Consumer Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	22,453	22,812
Total Past Due and Non-performing Loans	455	479
Non-performing Loans	298	312
Purchased Credit Impaired	334	381
Total Loans	23,242	23,672
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	5,119	5,043
Total Past Due and Non-performing Loans	80	85
Non-performing Loans	62	58
Purchased Credit Impaired	314	355
Total Loans	5,513	5,483
Consumer Loans [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	10,862	11,721
Total Past Due and Non-performing Loans	263	285
Non-performing Loans	210	229
Purchased Credit Impaired	17	22
Total Loans	11,142	12,028
Consumer Loans [Member] | Consumer Direct Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,780	1,768
Total Past Due and Non-performing Loans	26	22
Non-performing Loans	4	4
Purchased Credit Impaired	3	4
Total Loans	1,809	1,794
Consumer Loans [Member] | Credit Card Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,119	1,081
Total Past Due and Non-performing Loans	25	25
Non-performing Loans	2	2
Purchased Credit Impaired	0	0
Total Loans	1,144	1,106
Consumer Loans [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,573	3,199
Total Past Due and Non-performing Loans	61	62
Non-performing Loans	20	19
Purchased Credit Impaired	0	0
Total Loans	3,634	3,261
Consumer Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	90	97
Consumer Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	11	16
Consumer Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	31	32
Consumer Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Direct Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	11	9
Consumer Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Credit Card Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	6	7
Consumer Loans [Member] | Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	31	33
Consumer Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	32	38
Consumer Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	3	7
Consumer Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	12	15
Consumer Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Direct Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	5	4
Consumer Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Credit Card Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	5	5
Consumer Loans [Member] | Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	7	7
Consumer Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	35	32
Consumer Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	4	4
Consumer Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Home Equity Loan [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	10	9
Consumer Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Direct Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	6	5
Consumer Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Credit Card Receivable [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	12	11
Consumer Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due and Non-performing Loans	$ 3	$ 3

Asset Quality - Narrative (Deta

Asset Quality - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)SecurityLoan	Dec. 31, 2017USD ($)SecurityLoan	Dec. 31, 2016USD ($)SecurityLoan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of carrying amount of our commercial nonperforming loans outstanding	75.00%
Percentage of nonperforming loans outstanding face value	80.00%
Percentage of loans held for sale and other nonperforming assets	81.00%
Net reduction to interest income	$ 30	$ 25	$ 26
Commitments outstanding to lend additional funds to borrowers	5	2
Financial receivable, modifications, subsequent default, recorded investment	11
OREO	35	31
Provision (credit) for loan and lease losses	$ 248	$ 237	$ 280
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | SecurityLoan	1	0	0
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment		$ 4	$ 9
Number of loans | SecurityLoan	253	147	187
Real Estate - Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financial receivable, modifications, subsequent default, recorded investment	$ 113	$ 142
Continuing Operations [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision (credit) for loan and lease losses	240	227	$ 267
Continuing Operations [Member] | Purchase Credit Impaired Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision (credit) for loan and lease losses	2	3
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income recognized on outstanding balances	13	9	10
Commercial Loans [Member] | Continuing Operations [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision (credit) for loan and lease losses	151	130	179
Consumer Loans [Member] | Continuing Operations [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision (credit) for loan and lease losses	89	97	88
Consumer Loans [Member] | Continuing Operations [Member] | Real Estate - Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision (credit) for loan and lease losses	1	(11)	$ 2
Foreclosed Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
OREO	$ 35	$ 26

Asset Quality - Breakdown of In

Asset Quality - Breakdown of Individually Impaired Loans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	$ 238	$ 213
With related allowance recorded, Recorded Investment	209	141
Recorded Investment	447	354
With no related allowance recorded, Unpaid Principal Balance	311	246
With related allowance recorded, Unpaid Principal Balance	245	159
Unpaid Principal Balance	556	405
Specific Allowance	19	23
Average Recorded Investment	401	428	$ 405
Commercial Loans [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	182	138
With related allowance recorded, Recorded Investment	46	10
With no related allowance recorded, Unpaid Principal Balance	245	171
With related allowance recorded, Unpaid Principal Balance	50	28
Specific Allowance	6	6
Average Recorded Investment	188	219	187
Commercial Loans [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	118	126
With related allowance recorded, Recorded Investment	44	10
With no related allowance recorded, Unpaid Principal Balance	175	153
With related allowance recorded, Unpaid Principal Balance	47	28
Specific Allowance	5	6
Average Recorded Investment	149	210	176
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	64	12
With related allowance recorded, Recorded Investment	2	0
With no related allowance recorded, Unpaid Principal Balance	70	18
With related allowance recorded, Unpaid Principal Balance	3	0
Specific Allowance	1	0
Average Recorded Investment	39	9	8
Commercial Loans [Member] | Commercial Real Estate: Construction [Member]
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0	0	3
Commercial Loans [Member] | Commercial Real Estate Loans [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	64	12
With related allowance recorded, Recorded Investment	2	0
With no related allowance recorded, Unpaid Principal Balance	70	18
With related allowance recorded, Unpaid Principal Balance	3	0
Specific Allowance	1	0
Average Recorded Investment	39	9	11
Consumer Loans [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	56	75
With related allowance recorded, Recorded Investment	163	131
With no related allowance recorded, Unpaid Principal Balance	66	75
With related allowance recorded, Unpaid Principal Balance	195	131
Specific Allowance	13	17
Average Recorded Investment	213	209	218
Consumer Loans [Member] | Home Equity Loan [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	49	56
With related allowance recorded, Recorded Investment	78	61
With no related allowance recorded, Unpaid Principal Balance	56	56
With related allowance recorded, Unpaid Principal Balance	85	61
Specific Allowance	8	9
Average Recorded Investment	122	121	125
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	4	17
With related allowance recorded, Recorded Investment	45	32
With no related allowance recorded, Unpaid Principal Balance	5	17
With related allowance recorded, Unpaid Principal Balance	70	32
Specific Allowance	3	5
Average Recorded Investment	49	50	53
Consumer Loans [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	2	2
With related allowance recorded, Recorded Investment	34	32
With no related allowance recorded, Unpaid Principal Balance	4	2
With related allowance recorded, Unpaid Principal Balance	34	32
Specific Allowance	2	3
Average Recorded Investment	35	32	34
Consumer Loans [Member] | Consumer Direct Loans [Member]
Financing Receivable, Impaired [Line Items]
With no related allowance recorded, Recorded Investment	1	0
With related allowance recorded, Recorded Investment	3	4
With no related allowance recorded, Unpaid Principal Balance	1	0
With related allowance recorded, Unpaid Principal Balance	3	4
Specific Allowance	0	0
Average Recorded Investment	4	3	3
Consumer Loans [Member] | Consumer Credit Card [Member]
Financing Receivable, Impaired [Line Items]
With related allowance recorded, Recorded Investment	3	2
With related allowance recorded, Unpaid Principal Balance	3	2
Specific Allowance	0	0
Average Recorded Investment	$ 3	$ 3	$ 3

Asset Quality - Post-Modificati

Asset Quality - Post-Modification Outstanding Recorded Investment by Concession Type for Our Commercial Accruing and Nonaccruing TDRs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
Total commercial and consumer TDRs	$ 186	$ 130
Total loans	89,552	86,405
Commercial Loans [Member]
Financing Receivable, Modifications [Line Items]
Extension of maturity date	15	12
Payment or covenant modification/deferment	99	46
Bankruptcy plan modification	7	31
Total	121	89
Total loans	66,310	62,733
Consumer Loans [Member]
Financing Receivable, Modifications [Line Items]
Interest rate reduction	27	13
Forgiveness of principal	0	0
Other	38	28
Total	65	41
Total loans	$ 23,242	$ 23,672

Asset Quality - Summary of Post

Asset Quality - Summary of Post-Modification Outstanding Recorded Investment TDRs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Financing Receivables, Modifications, Rollforward [Roll Forward]
Balance at beginning of the period	$ 317	$ 280
Additions	228	165
Payments	(110)	(111)
Charge-offs	(36)	(17)
Balance at end of period	$ 399	$ 317

Asset Quality - Breakdown of No

Asset Quality - Breakdown of Nonperforming TDRs by Loans Category (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)SecurityLoan	Dec. 31, 2017USD ($)SecurityLoan
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	6,084	5,184
Pre-modification Outstanding Recorded Investment	$ 491	$ 398
Post-modification Outstanding Recorded Investment	$ 399	$ 317
Prior-Year Accruing [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	3,021	2,562
Pre-modification Outstanding Recorded Investment	$ 195	$ 171
Post-modification Outstanding Recorded Investment	$ 152	$ 128
Nonperforming [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	3,063	2,622
Pre-modification Outstanding Recorded Investment	$ 296	$ 227
Post-modification Outstanding Recorded Investment	$ 247	$ 189
Commercial Loans [Member] | Prior-Year Accruing [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	13	4
Pre-modification Outstanding Recorded Investment	$ 37	$ 30
Post-modification Outstanding Recorded Investment	$ 32	$ 13
Commercial Loans [Member] | Commercial, Financial and Agricultural [Member] | Prior-Year Accruing [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	11	4
Pre-modification Outstanding Recorded Investment	$ 37	$ 30
Post-modification Outstanding Recorded Investment	$ 32	$ 13
Commercial Loans [Member] | Nonperforming [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	41	28
Pre-modification Outstanding Recorded Investment	$ 187	$ 125
Post-modification Outstanding Recorded Investment	$ 147	$ 98
Commercial Loans [Member] | Nonperforming [Member] | Commercial, Financial and Agricultural [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	35	20
Pre-modification Outstanding Recorded Investment	$ 121	$ 109
Post-modification Outstanding Recorded Investment	$ 85	$ 86
Commercial Real Estate Portfolio Segment [Member] | Commercial, Financial and Agricultural [Member] | Prior-Year Accruing [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	2	0
Pre-modification Outstanding Recorded Investment	$ 0	$ 0
Post-modification Outstanding Recorded Investment	$ 0	$ 0
Commercial Real Estate Portfolio Segment [Member] | Nonperforming [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	6	8
Pre-modification Outstanding Recorded Investment	$ 66	$ 16
Post-modification Outstanding Recorded Investment	$ 62	$ 12
Commercial Real Estate Portfolio Segment [Member] | Nonperforming [Member] | Commercial Real Estate Loans [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	6	8
Pre-modification Outstanding Recorded Investment	$ 66	$ 16
Post-modification Outstanding Recorded Investment	$ 62	$ 12
Consumer Loans [Member] | Prior-Year Accruing [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	3,008	2,558
Pre-modification Outstanding Recorded Investment	$ 158	$ 141
Post-modification Outstanding Recorded Investment	$ 120	$ 115
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | Prior-Year Accruing [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	491	484
Pre-modification Outstanding Recorded Investment	$ 36	$ 31
Post-modification Outstanding Recorded Investment	$ 30	$ 31
Consumer Loans [Member] | Home Equity Loan [Member] | Prior-Year Accruing [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	1,403	1,276
Pre-modification Outstanding Recorded Investment	$ 82	$ 75
Post-modification Outstanding Recorded Investment	$ 64	$ 59
Consumer Loans [Member] | Consumer Direct Loans [Member] | Prior-Year Accruing [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	79	48
Pre-modification Outstanding Recorded Investment	$ 4	$ 3
Post-modification Outstanding Recorded Investment	$ 3	$ 2
Consumer Loans [Member] | Consumer Credit Card [Member] | Prior-Year Accruing [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	479	430
Pre-modification Outstanding Recorded Investment	$ 3	$ 1
Post-modification Outstanding Recorded Investment	$ 1	$ 1
Consumer Loans [Member] | Consumer Indirect Loans [Member] | Prior-Year Accruing [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	556	320
Pre-modification Outstanding Recorded Investment	$ 33	$ 31
Post-modification Outstanding Recorded Investment	$ 22	$ 22
Consumer Loans [Member] | Nonperforming [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	3,022	2,594
Pre-modification Outstanding Recorded Investment	$ 109	$ 102
Post-modification Outstanding Recorded Investment	$ 100	$ 91
Consumer Loans [Member] | Nonperforming [Member] | Real Estate - Residential Mortgage [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	281	308
Pre-modification Outstanding Recorded Investment	$ 21	$ 18
Post-modification Outstanding Recorded Investment	$ 20	$ 18
Consumer Loans [Member] | Nonperforming [Member] | Home Equity Loan [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	1,142	1,025
Pre-modification Outstanding Recorded Investment	$ 66	$ 64
Post-modification Outstanding Recorded Investment	$ 63	$ 57
Consumer Loans [Member] | Nonperforming [Member] | Consumer Direct Loans [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	171	114
Pre-modification Outstanding Recorded Investment	$ 2	$ 2
Post-modification Outstanding Recorded Investment	$ 1	$ 2
Consumer Loans [Member] | Nonperforming [Member] | Consumer Credit Card [Member] | Nonperforming [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	330	322
Pre-modification Outstanding Recorded Investment	$ 2	$ 2
Post-modification Outstanding Recorded Investment	$ 2	$ 1
Consumer Loans [Member] | Nonperforming [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans | SecurityLoan	1,098	825
Pre-modification Outstanding Recorded Investment	$ 18	$ 16
Post-modification Outstanding Recorded Investment	$ 14	$ 13

Asset Quality - Changes in Allo

Asset Quality - Changes in Allowance for Loan and Lease Losses by Loan Category (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 893	$ 882	$ 824
Provision	248	237	280
Charge-offs	(339)	(328)	(289)
Recoveries	95	102	67
Ending balance	897	893	882
Provision for credit losses	246	229	266
Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	877	858	796
Provision	240	227	267
Charge-offs	(324)	(302)	(261)
Recoveries	90	94	56
Ending balance	883	877	858
Provision for credit losses	6	2	1
Discontinued Operations [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	16	24	28
Provision	8	10	13
Charge-offs	(15)	(26)	(28)
Recoveries	5	8	11
Ending balance	14	16	24
Commercial Loans [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	735	716	656
Provision	151	130	179
Charge-offs	(190)	(160)	(144)
Recoveries	47	49	25
Ending balance	743	735	716
Commercial Loans [Member] | Continuing Operations [Member] | Commercial, Financial and Agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	529	508	450
Provision	125	114	165
Charge-offs	(159)	(133)	(118)
Recoveries	37	40	11
Ending balance	532	529	508
Commercial Loans [Member] | Continuing Operations [Member] | Commercial Real Estate: Commercial Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	133	144	134
Provision	27	(2)	6
Charge-offs	(21)	(11)	(5)
Recoveries	3	2	9
Ending balance	142	133	144
Commercial Loans [Member] | Continuing Operations [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	30	22	25
Provision	1	9	4
Charge-offs	0	(2)	(9)
Recoveries	2	1	2
Ending balance	33	30	22
Commercial Loans [Member] | Continuing Operations [Member] | Commercial Lease Financing [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	43	42	47
Provision	(2)	9	4
Charge-offs	(10)	(14)	(12)
Recoveries	5	6	3
Ending balance	36	43	42
Consumer Loans [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	142	142	140
Provision	89	97	88
Charge-offs	(134)	(142)	(117)
Recoveries	43	45	31
Ending balance	140	142	142
Consumer Loans [Member] | Continuing Operations [Member] | Real Estate - Residential Mortgage [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	7	17	18
Provision	1	(11)	2
Charge-offs	(3)	(3)	(4)
Recoveries	2	4	1
Ending balance	7	7	17
Consumer Loans [Member] | Continuing Operations [Member] | Home Equity Loan [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	43	54	57
Provision	2	4	13
Charge-offs	(21)	(30)	(30)
Recoveries	11	15	14
Ending balance	35	43	54
Consumer Loans [Member] | Continuing Operations [Member] | Consumer Direct Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	28	24	20
Provision	31	32	26
Charge-offs	(36)	(34)	(27)
Recoveries	7	6	5
Ending balance	30	28	24
Consumer Loans [Member] | Continuing Operations [Member] | Consumer Credit Card [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	44	38	32
Provision	41	45	37
Charge-offs	(44)	(44)	(35)
Recoveries	7	5	4
Ending balance	48	44	38
Consumer Loans [Member] | Continuing Operations [Member] | Consumer Indirect Loans [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	20	9	13
Provision	14	27	10
Charge-offs	(30)	(31)	(21)
Recoveries	16	15	7
Ending balance	$ 20	$ 20	$ 9

Asset Quality - Breakdown of Al

Asset Quality - Breakdown of Allowance for Loan and Lease Losses and Corresponding Loan Balances (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance, Total ALLL - Including Discontinued Operations	$ 21	$ 26
Collectively Evaluated for Impairment Allowance, Total ALLL - Including Discontinued Operations	871	861
Purchased Credit Impaired Allowance, Total ALLL - Including Discontinued Operations	5	6
Loans Outstanding, Total ALLL - Including Discontinued Operations	90,625	87,719
Individually Evaluated for Impairment Outstanding, Total ALLL - Including Discontinued Operations	470	375
Collectively Evaluated for Impairment Outstanding, Total ALLL - Including Discontinued Operations	89,580	86,606
Purchased Credit Impaired Outstanding, Total ALLL - Including Discontinued Operations	575	738
Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	19	23
Collectively Evaluated for Impairment Allowance	859	848
Purchase Credit Impairment Allowance	5	6
Loans Outstanding	89,552	86,405
Individually Evaluated for Impairment Outstanding	447	354
Collectively Evaluated for Impairment Outstanding	88,530	85,313
Purchase Credit Impairment Outstanding	575	738
Discontinued Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	2	3
Collectively Evaluated for Impairment Allowance	12	13
Purchase Credit Impairment Allowance	0	0
Loans Outstanding	1,073	1,314
Individually Evaluated for Impairment Outstanding	23	21
Collectively Evaluated for Impairment Outstanding	1,050	1,293
Purchase Credit Impairment Outstanding	0	0
Loans carried at fair value	2
Commercial Loans [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	5	6
Collectively Evaluated for Impairment Allowance	734	724
Purchase Credit Impairment Allowance	4	5
Loans Outstanding	66,310	62,733
Individually Evaluated for Impairment Outstanding	228	148
Collectively Evaluated for Impairment Outstanding	65,841	62,228
Purchase Credit Impairment Outstanding	241	357
Commercial Loans [Member] | Commercial, Financial and Agricultural [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	5	6
Collectively Evaluated for Impairment Allowance	526	520
Purchase Credit Impairment Allowance	1	3
Loans Outstanding	45,753	41,859
Individually Evaluated for Impairment Outstanding	162	136
Collectively Evaluated for Impairment Outstanding	45,530	41,640
Purchase Credit Impairment Outstanding	61	83
Commercial Loans [Member] | Commercial Real Estate: Commercial Mortgage [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	0	0
Collectively Evaluated for Impairment Allowance	139	131
Purchase Credit Impairment Allowance	3	2
Loans Outstanding	14,285	14,088
Individually Evaluated for Impairment Outstanding	66	12
Collectively Evaluated for Impairment Outstanding	14,041	13,828
Purchase Credit Impairment Outstanding	178	248
Commercial Loans [Member] | Commercial Real Estate: Construction [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	0	0
Collectively Evaluated for Impairment Allowance	33	30
Purchase Credit Impairment Allowance	0	0
Loans Outstanding	1,666	1,960
Individually Evaluated for Impairment Outstanding	0	0
Collectively Evaluated for Impairment Outstanding	1,664	1,934
Purchase Credit Impairment Outstanding	2	26
Commercial Loans [Member] | Commercial Real Estate Loans [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	0	0
Collectively Evaluated for Impairment Allowance	172	161
Purchase Credit Impairment Allowance	3	2
Loans Outstanding	15,951	16,048
Individually Evaluated for Impairment Outstanding	66	12
Collectively Evaluated for Impairment Outstanding	15,705	15,762
Purchase Credit Impairment Outstanding	180	274
Commercial Loans [Member] | Commercial Lease Financing [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	0	0
Collectively Evaluated for Impairment Allowance	36	43
Purchase Credit Impairment Allowance	0	0
Loans Outstanding	4,606	4,826
Individually Evaluated for Impairment Outstanding	0	0
Collectively Evaluated for Impairment Outstanding	4,606	4,826
Purchase Credit Impairment Outstanding	0	0
Consumer Loans [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	14	17
Collectively Evaluated for Impairment Allowance	125	124
Purchase Credit Impairment Allowance	1	1
Loans Outstanding	23,242	23,672
Individually Evaluated for Impairment Outstanding	219	206
Collectively Evaluated for Impairment Outstanding	22,689	23,085
Purchase Credit Impairment Outstanding	334	381
Consumer Loans [Member] | Real Estate - Residential Mortgage [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	3	5
Collectively Evaluated for Impairment Allowance	4	2
Purchase Credit Impairment Allowance	0	0
Loans Outstanding	5,513	5,483
Individually Evaluated for Impairment Outstanding	49	49
Collectively Evaluated for Impairment Outstanding	5,150	5,079
Purchase Credit Impairment Outstanding	314	355
Consumer Loans [Member] | Home Equity Loan [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	8	9
Collectively Evaluated for Impairment Allowance	26	33
Purchase Credit Impairment Allowance	1	1
Loans Outstanding	11,142	12,028
Individually Evaluated for Impairment Outstanding	127	117
Collectively Evaluated for Impairment Outstanding	10,998	11,889
Purchase Credit Impairment Outstanding	17	22
Consumer Loans [Member] | Consumer Direct Loans [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	0	0
Collectively Evaluated for Impairment Allowance	30	28
Purchase Credit Impairment Allowance	0	0
Loans Outstanding	1,809	1,794
Individually Evaluated for Impairment Outstanding	4	4
Collectively Evaluated for Impairment Outstanding	1,802	1,786
Purchase Credit Impairment Outstanding	3	4
Consumer Loans [Member] | Credit Card Receivable [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	0	0
Collectively Evaluated for Impairment Allowance	48	44
Purchase Credit Impairment Allowance	0	0
Loans Outstanding	1,144	1,106
Individually Evaluated for Impairment Outstanding	3	2
Collectively Evaluated for Impairment Outstanding	1,141	1,104
Purchase Credit Impairment Outstanding	0	0
Consumer Loans [Member] | Consumer Indirect Loans [Member] | Continuing Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Individually Evaluated for Impairment Allowance	3	3
Collectively Evaluated for Impairment Allowance	17	17
Purchase Credit Impairment Allowance	0	0
Loans Outstanding	3,634	3,261
Individually Evaluated for Impairment Outstanding	36	34
Collectively Evaluated for Impairment Outstanding	3,598	3,227
Purchase Credit Impairment Outstanding	0	0
Education Lending [Member] | Discontinued Operations [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans carried at fair value	$ 2	$ 2

Asset Quality - Changes in Liab

Asset Quality - Changes in Liability for Credit Losses on Lending Related Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$ 57	$ 55	$ 56
Provision (credit) for losses on lending-related commitments	6	2	(1)
Balance at end of period	$ 63	$ 57	$ 55

Asset Quality - Changes in Outs

Asset Quality - Changes in Outstanding Unpaid Principal Balance, Carrying Amount, and Accretable Yield for PCI Loans (Details) - Purchase Credit Impaired Loans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accretable Yield
Balance at beginning of period	$ 131	$ 197
Additions	0	(32)
Accretion	(42)	(44)
Net reclassifications from non-accretable to accretable	50	15
Payments received, net	(21)	(4)
Disposals	0	(1)
Loans charged off	(1)	0
Balance at end of period	117	131
Carrying Amount	571	738	$ 865
Outstanding Unpaid Principal Balance	$ 607	$ 803	$ 1,002

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	$ 849	$ 836
Securities available for sale	19,428	18,139
Loans, net of unearned income (residential)	89,552	86,405
Netting adjustments	(333)	(443)
Total derivative assets	531	669
LIABILITIES MEASURED ON A RECURRING BASIS
Netting adjustments	(337)	(616)
Government and agency bonds - U.S. [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	147	157
State and municpal bonds [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	7	9
Other Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	20	20
Residential Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	2,105	1,439
Other Mortgage-Backed Securities [Member] | Commercial Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	3,187	1,854
Fair Value, Measurements, Recurring [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	824	821
Commercial loans	25	15
Total trading account assets	849	836
Securities available for sale	19,428	18,139
Total other investments	115	144
Loans, net of unearned income (residential)	3	2
Loans held for sale	54	71
Derivative assets	864	1,112
Netting adjustments	(333)	(443)
Total derivative assets	531	669
Total assets on a recurring basis at fair value	20,980	19,861
LIABILITIES MEASURED ON A RECURRING BASIS
Total liabilities on a recurring basis at fair value	930	925
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	13,962	14,660
Fair Value, Measurements, Recurring [Member] | Government and agency bonds - U.S. [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	578	615
Securities available for sale	147	157
Fair Value, Measurements, Recurring [Member] | State and municpal bonds [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	60	37
Securities available for sale	7	9
Fair Value, Measurements, Recurring [Member] | Other Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	22	65
Securities available for sale	20	20
Fair Value, Measurements, Recurring [Member] | Commercial Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	3,187	1,854
Fair Value, Measurements, Recurring [Member] | Principal Direct Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	1	13
Fair Value, Measurements, Recurring [Member] | Principal Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	97	137
Fair Value, Measurements, Recurring [Member] | Equity Investments Direct [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	8	7
Fair Value, Measurements, Recurring [Member] | Equity Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	18	7
Fair Value, Measurements, Recurring [Member] | Other Mortgage-Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	164	104
Fair Value, Measurements, Recurring [Member] | Other Mortgage-Backed Securities [Member] | Residential Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	2,105	1,439
Fair Value, Measurements, Recurring [Member] | Short Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Short positions	544	634
Fair Value, Measurements, Recurring [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	723	907
Netting adjustments	(337)	(616)
Total derivative liabilities	386	291
Fair Value, Measurements, Recurring [Member] | Interest Rate [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	415	722
Fair Value, Measurements, Recurring [Member] | Interest Rate [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	297	520
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	106	130
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	95	124
Fair Value, Measurements, Recurring [Member] | Commodity [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	333	255
Fair Value, Measurements, Recurring [Member] | Commodity [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	323	246
Fair Value, Measurements, Recurring [Member] | Credit [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	1	1
Fair Value, Measurements, Recurring [Member] | Credit [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	1	4
Fair Value, Measurements, Recurring [Member] | Other Credit Derivatives [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	9	4
Fair Value, Measurements, Recurring [Member] | Other Credit Derivatives [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	7	13
Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Commercial loans	0	0
Total trading account assets	0	0
Securities available for sale	0	0
Total other investments	0	0
Loans, net of unearned income (residential)	0	0
Loans held for sale	0	0
Derivative assets	70	100
Netting adjustments	0	0
Total derivative assets	70	100
Total assets on a recurring basis at fair value	70	100
LIABILITIES MEASURED ON A RECURRING BASIS
Total liabilities on a recurring basis at fair value	72	170
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Government and agency bonds - U.S. [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | State and municpal bonds [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Other Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Commercial Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Principal Direct Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Principal Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Equity Investments Direct [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Equity Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Other Mortgage-Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Other Mortgage-Backed Securities [Member] | Residential Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Short Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Short positions	14	72
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	58	98
Netting adjustments	0	0
Total derivative liabilities	58	98
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	70	100
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	58	98
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Commodity [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Commodity [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Credit [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Credit [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Other Credit Derivatives [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Other Credit Derivatives [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	824	821
Commercial loans	25	15
Total trading account assets	849	836
Securities available for sale	19,408	18,119
Total other investments	1	4
Loans, net of unearned income (residential)	0	0
Loans held for sale	54	70
Derivative assets	786	999
Netting adjustments	0	0
Total derivative assets	786	999
Total assets on a recurring basis at fair value	21,098	20,028
LIABILITIES MEASURED ON A RECURRING BASIS
Total liabilities on a recurring basis at fair value	1,195	1,371
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	13,962	14,660
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Government and agency bonds - U.S. [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	578	615
Securities available for sale	147	157
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | State and municpal bonds [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	60	37
Securities available for sale	7	9
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Other Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	22	65
Securities available for sale	0	0
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Commercial Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	3,187	1,854
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Principal Direct Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Principal Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	0	0
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Equity Investments Direct [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	1	4
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Equity Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	1	4
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Other Mortgage-Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	164	104
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Other Mortgage-Backed Securities [Member] | Residential Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	2,105	1,439
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Short Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Short positions	530	562
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	665	809
Netting adjustments	0	0
Total derivative liabilities	665	809
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	410	713
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	297	520
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	36	30
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	37	26
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Commodity [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	333	255
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Commodity [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	323	246
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Credit [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	1	0
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Credit [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	1	4
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Other Credit Derivatives [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	6	1
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Other Credit Derivatives [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	7	13
Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Commercial loans	0	0
Total trading account assets	0	0
Securities available for sale	20	20
Total other investments	8	16
Loans, net of unearned income (residential)	3	2
Loans held for sale	0	1
Derivative assets	8	13
Netting adjustments	0	0
Total derivative assets	8	13
Total assets on a recurring basis at fair value	39	52
LIABILITIES MEASURED ON A RECURRING BASIS
Total liabilities on a recurring basis at fair value	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Government and agency bonds - U.S. [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | State and municpal bonds [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Other Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Securities available for sale	20	20
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Commercial Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Principal Direct Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	1	13
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Principal Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	1	13
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Equity Investments Direct [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	7	3
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Equity Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	7	3
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Other Mortgage-Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total trading account securities	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Other Mortgage-Backed Securities [Member] | Residential Mortgage Backed Securities [Member]
ASSETS MEASURED ON A RECURRING BASIS
Securities available for sale	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Short Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Short positions	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Netting adjustments	0	0
Total derivative liabilities	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	5	9
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contract [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Commodity [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Commodity [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Credit [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	0	1
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Credit [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Other Credit Derivatives [Member]
ASSETS MEASURED ON A RECURRING BASIS
Derivative assets	3	3
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Other Credit Derivatives [Member] | Long Positions [Member]
LIABILITIES MEASURED ON A RECURRING BASIS
Derivative liabilities	0	0
Fair Value Measured at Net Asset Value Per Share [Member] | Fair Value, Measurements, Recurring [Member] | Principal Indirect Investments [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	96	124
Fair Value Measured at Net Asset Value Per Share [Member] | Fair Value, Measurements, Recurring [Member] | Equity Investments Direct, NAV [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	1	0
Fair Value Measured at Net Asset Value Per Share [Member] | Fair Value, Measurements, Recurring [Member] | Equity Investments Indirect, NAV [Member]
ASSETS MEASURED ON A RECURRING BASIS
Total other investments	$ 9	$ 0

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Value of Direct and Indirect Investments, Related Unfunded Commitments and Financial Support Provided (Details) - Principal Investments [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	$ 97
Unfunded Commitments	26
Funded Commitments	1	$ 1
Funded Other	0	0
Direct Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	1
Unfunded Commitments	0
Funded Commitments	0	0
Funded Other	0	0
Indirect Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value	96
Unfunded Commitments	26
Funded Commitments	1	1
Funded Other	$ 0	$ 0

Fair Value Measurements - Chang

Fair Value Measurements - Change in Fair Values of Level 3 Financial Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Available-for-sale Securities [Member] | Other Securities [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	$ 20	$ 17
Gains (Losses) included in comprehensive income	0	3
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	20	20
Unrealized Gains (Losses) Included in Earnings	0	0
Other Investments [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	3	0
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	4	3
Transfers out of Level 3	0	0
End of Period Balance	7	3
Unrealized Gains (Losses) Included in Earnings	0	0
Other Investments [Member] | Principal Direct Investments [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	13	27
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	(1)	(6)
Purchases	5	0
Sales	(16)	(8)
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	1	13
Unrealized Gains (Losses) Included in Earnings	0	(1)
Interest Rate [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	9	7
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	(2)	(2)
Purchases	1	0
Sales	(2)	0
Settlements	0	0
Transfers Other	0	0
Transfers into Level 3	7	13
Transfers out of Level 3	(8)	(9)
End of Period Balance	5	9
Unrealized Gains (Losses) Included in Earnings	0	0
Credit [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	1	1
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	(31)	(16)
Purchases	0	0
Sales	0	0
Settlements	30	16
Transfers Other	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	0	1
Unrealized Gains (Losses) Included in Earnings	0	0
Other Credit Derivatives [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	3	2
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	0	1
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	3	3
Unrealized Gains (Losses) Included in Earnings	0	0
Loans Held For Sale Fair Value [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	1	0
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	(1)	(3)
Settlements	0	0
Transfers Other	(1)	4
Transfers into Level 3	1	0
Transfers out of Level 3	0	0
End of Period Balance	0	1
Unrealized Gains (Losses) Included in Earnings	0	0
Loans Held For Investment Fair Value [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	2	0
Gains (Losses) included in comprehensive income	0	0
Gains (Losses) Included in Earnings	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Transfers Other	1	2
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
End of Period Balance	3	2
Unrealized Gains (Losses) Included in Earnings	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net loans	$ 88,669,000,000	$ 85,528,000,000
Equity securities without readily determinable fair value	107,000,000
Impairment on equity securities without readily determinable fair value	0
Discontinued Operations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans carried at fair value	2,000,000
Discontinued Operations [Member] | Education Lending [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net loans	1,100,000,000	1,300,000,000
Loans carried at fair value	2,000,000	2,000,000
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total other investments	666,000,000	726,000,000
Net loans	88,666,000,000	85,526,000,000
Loans carried at fair value	3,000,000	2,000,000
Carrying Amount [Member] | Discontinued Operations [Member] | Education Lending [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net loans	1,100,000,000	1,300,000,000
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total other investments	666,000,000	726,000,000
Net loans	86,224,000,000	84,003,000,000
Loans carried at fair value	3,000,000	2,000,000
Estimate of Fair Value Measurement [Member] | Discontinued Operations [Member] | Education Lending [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Net loans	900,000,000	1,100,000,000
Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total other investments	115,000,000	144,000,000
Liabilities measured at fair value on non recurring basis	930,000,000	925,000,000
Fair Value, Measurements, Nonrecurring [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities measured at fair value on non recurring basis	0	0
Principal Direct Investments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total other investments	$ 1,000,000	$ 13,000,000

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Nonrecurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2018
ASSETS MEASURED ON A NONRECURRING BASIS
Impairment related to tax credit carryforwards impacted by TCJ Act	$ 31
Fair Value, Measurements, Nonrecurring [Member]
ASSETS MEASURED ON A NONRECURRING BASIS
Impaired loans and leases	9	$ 42
Accrued income and other assets	138	16
Total assets on a recurring basis at fair value	147	58
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
ASSETS MEASURED ON A NONRECURRING BASIS
Impaired loans and leases	0	0
Accrued income and other assets	0	0
Total assets on a recurring basis at fair value	0	0
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
ASSETS MEASURED ON A NONRECURRING BASIS
Impaired loans and leases	0	0
Accrued income and other assets	5	0
Total assets on a recurring basis at fair value	5	0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
ASSETS MEASURED ON A NONRECURRING BASIS
Impaired loans and leases	9	42
Accrued income and other assets	133	16
Total assets on a recurring basis at fair value	142	$ 58
LIHTC And Historic Tax Credit Investments [Member]
ASSETS MEASURED ON A NONRECURRING BASIS
Tax credit carryforward	$ 119

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative Information about Level 3 Fair Value Measurements (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments	$ 666	$ 726
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Impaired loans and leases	42	9
Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Impaired loans and leases	$ 42	$ 9
Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member] | Minimum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Percentage of significant unobservable inputs	20.00%	0.00%
Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member] | Maximum [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Percentage of significant unobservable inputs	40.00%	50.00%
Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Percentage of significant unobservable inputs	21.00%	23.00%
Level 3 [Member] | Other Investments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments		$ 13
EBITDA Multiple [Member] | Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Percentage of significant unobservable inputs		6.00%
EBITDA Multiple (where applicable) [Member] | Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Weighted Average [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Percentage of significant unobservable inputs		6.00%

Fair Value Measurements - Fai_3

Fair Value Measurements - Fair Value Disclosures of Financial Instruments (Details) - USD ($) $ in Millions		Dec. 31, 2018	Dec. 31, 2017
ASSETS
Trading account assets		$ 849	$ 836
Held-to-maturity securities		11,519	11,830
Held-to-maturity securities		11,122	11,565
Loans, net of allowance, Carrying Amount		88,669	85,528
Loans held for sale, Carrying Amount	[1]	1,227	1,107
Derivative assets		531	669
Fair Value		19,428	18,139
LIABILITIES
Long-term debt, Carrying Amount		13,732	14,333
Carrying Amount [Member]
ASSETS
Trading account assets		849	836
Other investments		666	726
Loans, net of allowance		3	2
Held-to-maturity securities		11,519	11,830
Loans, net of allowance, Carrying Amount		88,666	85,526
Loans held for sale, Carrying Amount		1,173	1,036
Loans held for sale		54	71
Fair Value		19,428	18,139
Cash and short-term investments		3,240	5,118
LIABILITIES
Time deposits, Carrying Amount		13,245	11,647
Short-term borrowings, Carrying Amount		863	1,011
Long-term debt, Carrying Amount		13,732	14,333
Deposits with no stated maturity		94,064	93,588
Estimate of Fair Value Measurement [Member]
ASSETS
Trading account assets		849	836
Other investments		666	726
Loans, net of allowance		3	2
Held-to-maturity securities		11,122	11,565
Loans, net of allowance, Carrying Amount		86,224	84,003
Loans held for sale, Carrying Amount		1,173	1,036
Loans held for sale		54	71
Fair Value		19,428	18,139
Cash and short-term investments		3,240	5,118
LIABILITIES
Time deposits		13,331	11,750
Short-term borrowings		863	1,011
Long-term debt		13,787	14,626
Deposits with no stated maturity		94,064	93,588
Estimate of Fair Value Measurement [Member] | Level 1 [Member]
ASSETS
Trading account assets		0	0
Other investments		0	0
Loans, net of allowance		0	0
Held-to-maturity securities		0	0
Loans, net of allowance, Carrying Amount		0	0
Loans held for sale, Carrying Amount		0	0
Loans held for sale		0	0
Fair Value		0	0
Cash and short-term investments		3,240	5,118
LIABILITIES
Time deposits		0	0
Short-term borrowings		14	72
Long-term debt		12,576	13,407
Deposits with no stated maturity		0	0
Estimate of Fair Value Measurement [Member] | Level 2 [Member]
ASSETS
Trading account assets		849	836
Other investments		1	4
Loans, net of allowance		0	0
Held-to-maturity securities		11,122	11,565
Loans, net of allowance, Carrying Amount		0	0
Loans held for sale, Carrying Amount		0	0
Loans held for sale		54	70
Fair Value		19,408	18,119
Cash and short-term investments		0	0
LIABILITIES
Time deposits		13,331	11,750
Short-term borrowings		849	939
Long-term debt		1,211	1,219
Deposits with no stated maturity		94,064	93,588
Estimate of Fair Value Measurement [Member] | Level 3 [Member]
ASSETS
Trading account assets		0	0
Other investments		559	598
Loans, net of allowance		3	2
Held-to-maturity securities		0	0
Loans, net of allowance, Carrying Amount		86,224	84,003
Loans held for sale, Carrying Amount		1,173	1,036
Loans held for sale		0	1
Fair Value		20	20
Cash and short-term investments		0	0
LIABILITIES
Time deposits		0	0
Short-term borrowings		0	0
Long-term debt		0	0
Deposits with no stated maturity		0	0
Estimate of Fair Value Measurement [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
ASSETS
Other investments		106	124
Fair Value, Measurements, Recurring [Member]
ASSETS
Trading account assets		824	821
Other investments		115	144
Loans held for sale		54	71
Derivative assets		531	669
Fair Value		19,428	18,139
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
ASSETS
Trading account assets		0	0
Other investments		0	0
Loans held for sale		0	0
Derivative assets		70	100
Fair Value		0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
ASSETS
Trading account assets		824	821
Other investments		1	4
Loans held for sale		54	70
Derivative assets		786	999
Fair Value		19,408	18,119
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
ASSETS
Trading account assets		0	0
Other investments		8	16
Loans held for sale		0	1
Derivative assets		8	13
Fair Value		20	20
Other Securities [Member]
ASSETS
Held-to-maturity securities		12	15
Held-to-maturity securities		12	15
Fair Value		20	20
Other Securities [Member] | Fair Value, Measurements, Recurring [Member]
ASSETS
Trading account assets		22	65
Fair Value		20	20
Other Securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
ASSETS
Trading account assets		0	0
Fair Value		0	0
Other Securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
ASSETS
Trading account assets		22	65
Fair Value		0	0
Other Securities [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
ASSETS
Trading account assets		0	0
Fair Value		20	20
Not Designated as Hedging Instrument [Member] | Carrying Amount [Member]
ASSETS
Derivative assets		462	681
LIABILITIES
Derivative liabilities		395	289
Not Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member]
ASSETS
Derivative assets		462	681
Derivative assets, netting adjustment		(350)	(349)
LIABILITIES
Derivative liabilities		395	289
Derivative liabilities, netting adjustment		(338)	(568)
Not Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 1 [Member]
ASSETS
Derivative assets		68	99
LIABILITIES
Derivative liabilities		58	94
Not Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 2 [Member]
ASSETS
Derivative assets		736	918
LIABILITIES
Derivative liabilities		675	763
Not Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 3 [Member]
ASSETS
Derivative assets		8	13
LIABILITIES
Derivative liabilities		0	0
Designated as Hedging Instrument [Member] | Carrying Amount [Member]
ASSETS
Derivative assets		69	(12)
LIABILITIES
Derivative liabilities		(9)	2
Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member]
ASSETS
Derivative assets		69	(12)
Derivative assets, netting adjustment		17	(94)
LIABILITIES
Derivative liabilities		(9)	2
Derivative liabilities, netting adjustment		1	(48)
Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 1 [Member]
ASSETS
Derivative assets		2	1
LIABILITIES
Derivative liabilities		0	4
Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 2 [Member]
ASSETS
Derivative assets		50	81
LIABILITIES
Derivative liabilities		(10)	46
Designated as Hedging Instrument [Member] | Estimate of Fair Value Measurement [Member] | Level 3 [Member]
ASSETS
Derivative assets		0	0
LIABILITIES
Derivative liabilities		$ 0	$ 0
[1]	Total loans held for sale include Real estate — residential mortgage loans held for sale at fair value of $54 million at December 31, 2018 , and $71 million at December 31, 2017

Securities - Details of Securit

Securities - Details of Securities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
SECURITIES AVAILABLE FOR SALE
Amortized Cost	$ 19,917	$ 18,546
Gross Unrealized Gains	55	16
Gross Unrealized Losses	544	423
Fair Value	19,428	18,139
HELD-TO-MATURITY SECURITIES
Amortized Cost	11,519	11,830
Gross Unrealized Gains	4	7
Gross Unrealized Losses	401	272
Fair Value	11,122	11,565
Government and agency bonds - U.S. [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	150	159
Gross Unrealized Gains	0	0
Gross Unrealized Losses	3	2
Fair Value	147	157
State and municpal bonds [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	7	9
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	7	9
Collateralized Mortgage Obligations [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	14,315	14,985
Gross Unrealized Gains	20	10
Gross Unrealized Losses	373	335
Fair Value	13,962	14,660
HELD-TO-MATURITY SECURITIES
Amortized Cost	7,021	8,055
Gross Unrealized Gains	2	0
Gross Unrealized Losses	254	224
Fair Value	6,769	7,831
Residential Mortgage Backed Securities [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	2,128	1,456
Gross Unrealized Gains	13	3
Gross Unrealized Losses	36	20
Fair Value	2,105	1,439
HELD-TO-MATURITY SECURITIES
Amortized Cost	490	574
Gross Unrealized Gains	0	1
Gross Unrealized Losses	14	4
Fair Value	476	571
Other Securities [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	17	17
Gross Unrealized Gains	3	3
Gross Unrealized Losses	0	0
Fair Value	20	20
HELD-TO-MATURITY SECURITIES
Amortized Cost	12	15
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	12	15
Other Mortgage-Backed Securities [Member] | Commercial Mortgage Backed Securities [Member]
SECURITIES AVAILABLE FOR SALE
Amortized Cost	3,300	1,920
Gross Unrealized Gains	19	0
Gross Unrealized Losses	132	66
Fair Value	3,187	1,854
HELD-TO-MATURITY SECURITIES
Amortized Cost	3,996	3,186
Gross Unrealized Gains	2	6
Gross Unrealized Losses	133	44
Fair Value	$ 3,865	$ 3,148

Securities - Summary of Securit

Securities - Summary of Securities in Unrealized Loss Position (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Held-to-maturity securities:
Temporarily impaired securities, fair value, less than 12 months	$ 647	$ 10,991
Temporarily impaired securities, gross unrealized losses, less than 12 months	2	125
Temporarily impaired securities, fair value, 12 months or longer	24,158	16,041
Temporarily impaired securities, gross unrealized losses, 12 months or longer	943	570
Temporarily impaired securities, fair value	24,805	27,032
Temporarily impaired securities, gross unrealized losses	945	695
Government and agency bonds - U.S. [Member]
Securities available for sale:
Fair value, less than 12 months	0	41
Gross unrealized losses, less than 12 months (less than $1 million for agency residential mortgage-backed securities and U.S. Treasury, Agencies and Corporations)	0	1
Fair value, 12 months or longer	147	116
Gross unrealized losses, 12 months or longer	3	2
Fair value	147	157
Gross unrealized losses	3	2
Collateralized Mortgage Obligations [Member]
Securities available for sale:
Fair value, less than 12 months	570	6,153
Gross unrealized losses, less than 12 months (less than $1 million for agency residential mortgage-backed securities and U.S. Treasury, Agencies and Corporations)	2	74
Fair value, 12 months or longer	10,945	7,270
Gross unrealized losses, 12 months or longer	371	261
Fair value	11,515	13,423
Gross unrealized losses	373	335
Held-to-maturity securities:
Fair value, less than 12 months	0	2,201
Gross unrealized losses, less than 12 months (less than $1 million for agency commercial mortgage-backed securities and other securities)	0	27
Fair value, 12 months or longer	6,416	5,599
Gross unrealized losses, 12 months or longer (less than $1 million for other securities in 2017)	254	197
Fair value	6,416	7,800
Gross unrealized losses (less than $1 million for other securities)	254	224
Commercial Mortgage Backed Securities [Member]
Securities available for sale:
Fair value, less than 12 months	0	205
Gross unrealized losses, less than 12 months (less than $1 million for agency residential mortgage-backed securities and U.S. Treasury, Agencies and Corporations)	0	4
Fair value, 12 months or longer	1,729	1,649
Gross unrealized losses, 12 months or longer	132	62
Fair value	1,729	1,854
Gross unrealized losses		66
Held-to-maturity securities:
Fair value, less than 12 months	73	1,470
Gross unrealized losses, less than 12 months (less than $1 million for agency commercial mortgage-backed securities and other securities)	1	12
Fair value, 12 months or longer	3,359	495
Gross unrealized losses, 12 months or longer (less than $1 million for other securities in 2017)	133	32
Fair value	3,432	1,965
Gross unrealized losses (less than $1 million for other securities)	133	44
Other Securities [Member]
Held-to-maturity securities:
Fair value, less than 12 months	0	3
Gross unrealized losses, less than 12 months (less than $1 million for agency commercial mortgage-backed securities and other securities)	0	1
Fair value, 12 months or longer	0	4
Gross unrealized losses, 12 months or longer (less than $1 million for other securities in 2017)	0	1
Fair value	0	7
Gross unrealized losses (less than $1 million for other securities)	0	0
Other Mortgage-Backed Securities [Member] | Residential Mortgage Backed Securities [Member]
Securities available for sale:
Fair value, less than 12 months	4	666
Gross unrealized losses, less than 12 months (less than $1 million for agency residential mortgage-backed securities and U.S. Treasury, Agencies and Corporations)	1	7
Fair value, 12 months or longer	1,087	702
Gross unrealized losses, 12 months or longer	36	13
Fair value	1,091	1,368
Gross unrealized losses	36	20
Held-to-maturity securities:
Fair value, less than 12 months	0	252
Gross unrealized losses, less than 12 months (less than $1 million for agency commercial mortgage-backed securities and other securities)	0	1
Fair value, 12 months or longer	475	206
Gross unrealized losses, 12 months or longer (less than $1 million for other securities in 2017)	14	3
Fair value	475	458
Gross unrealized losses (less than $1 million for other securities)	14	$ 4
Other Mortgage-Backed Securities [Member] | Commercial Mortgage Backed Securities [Member]
Securities available for sale:
Gross unrealized losses	$ 132

Securities - Additional Informa

Securities - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018USD ($)loanposition	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Securities, Available-for-sale [Line Items]
Impairment recognized in earnings	$ 0	$ 0	$ 0
Loans pledged as collateral	$ 9,000,000,000
Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Number of fixed rate collateralized mortgage obligations | loan	450
Weighted average maturity collateralized mortgage life	4 years 9 months 29 days
Residential Mortgage Backed Securities [Member] | Other Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Gross unrealized losses	$ 36,000,000	20,000,000
Securities in unrealized loss positions, number of positions | position	252
Weighted average maturity mortgage backed securities	3 years 10 months 13 days
Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Gross unrealized losses		$ 66,000,000
Commercial Mortgage Backed Securities [Member] | Other Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Gross unrealized losses	$ 132,000,000
Securities in unrealized loss positions, number of positions | position	14
Weighted average maturity mortgage backed securities	4 years 1 month 13 days

Securities - Realized Gains and

Securities - Realized Gains and Losses on Securities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Securities, Available-for-sale [Line Items]
Realized gains	$ 0	$ 1	$ 0
Realized losses	0	0	0
Net securities gains (losses)	0	1	0
Maximum [Member]
Debt Securities, Available-for-sale [Line Items]
Net securities gains (losses)	$ 1	$ 1	$ 1

Securities - Securities by Matu

Securities - Securities by Maturity (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Amortized Cost of Securities Available for sale, Due in one year or less	$ 116
Amortized Cost of Securities Available for sale, Due after one through five years	12,298
Amortized Cost of Securities Available for sale, Due after five through ten years	7,492
Amortized Cost of Securities Available for sale, Due after ten years	11
Amortized Cost	19,917	$ 18,546
Fair Value of Securities Available for sale, Due in one year or less	116
Fair Value of Securities Available for sale, Due after one through five years	11,949
Fair Value of Securities Available for sale, Due after five through ten years	7,352
Fair Value of Securities Available for sale, Due after ten years	11
Total Fair Value of Securities Available-for-sale	19,428	18,139
Amortized Cost of Held-to-Maturity Securities, Due in one year or less	36
Amortized Cost of Held-to-Maturity Securities, Due after one through five years	6,402
Amortized Cost of Held-to-Maturity Securities, Due after five through ten years	5,081
Amortized Cost of Held-to-Maturity Securities, Due after ten years	0
Amortized Cost	11,519	11,830
Fair Value of Held-to-Maturity Securities, Due in one year or less	36
Fair Value of Held-to-Maturity Securities, Due after one through five years	6,210
Fair Value of Held-to-Maturity Securities, Due after five through ten years	4,876
Fair Value of Held-to-Maturity Securities, Due after ten years	0
Total Fair Value of Held-to-Maturity Securities	$ 11,122	$ 11,565

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities - Additional Information (Details)	12 Months Ended
	Dec. 31, 2018USD ($)derivativerating	Dec. 31, 2017USD ($)rating
Credit Derivatives [Line Items]
Derivative assets after effects of bilateral collateral and master netting agreements	$ 69,000,000
Derivative liabilities after effects of bilateral collateral and master netting agreements	(9,000,000)
Derivative assets not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses	462,000,000
Derivative liabilities not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses	395,000,000
Reclassify of after-tax net losses on derivative instruments from AOCI	$ 38,000,000
Length of time hedge in cash flow hedge	12 months
Reclassification of net losses related to terminated cash flow hedges from AOCI to income	$ 31,000,000
Maximum length of time over which forecasted transactions are hedged, years	10 years
Other Comprehensive income unrealized gain on derivatives arising during period net of tax	$ 27,000,000
Cash collateral netted against derivative assets	33,000,000	$ (23,000,000)
Collateral netted against derivative liabilities	37,000,000	150,000,000
Gross exposure on derivatives, after taking into account the effects of bilateral collateral and master netting agreements	382,000,000
Net exposure on derivatives, after taking into account, the effects of bilateral collateral and master netting agreements	241,000,000
Over-collateralization on derivatives to broker-dealers and banks, after the application of master netting agreements and collateral	237,000,000
Additional collateral held in the form of securities	4,000,000
Default reserve associated with uncollateralized contracts	4,000,000
Gross exposure on derivatives after taking into account effects of master netting agreements	345,000,000
Net exposure on derivatives with clients after application of master netting agreements collateral and related reserve	290,000,000
Net liability position totaled	$ (1,000,000)	$ (3,000,000)
Number of credit risk derivatives held | derivative	0
KeyBank (consolidated) [Member]
Credit Derivatives [Line Items]
Net liability position totaled	$ 66,000,000
Derivative assets included in net liability position	80,000,000
Derivative liabilities included in net liability position	146,000,000
Cash and securities collateral posted	$ 55,000,000
KeyBank (consolidated) [Member] | Unsecured Debt [Member]
Credit Derivatives [Line Items]
Number of ratings above noninvestment | rating	4	4
KeyBank (consolidated) [Member] | Maximum [Member] | Unsecured Debt [Member]
Credit Derivatives [Line Items]
Payments to terminate contracts	$ 4,000,000	$ 12,000,000
Key Corp [Member]
Credit Derivatives [Line Items]
Additional collateral held in the form of securities	$ 0	$ 0

Derivatives and Hedging Activ_4

Derivatives and Hedging Activities - Fair Values, Volume of Activity and Gain (Loss) Information Related to Derivative Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Notional Amount	$ 102,645	$ 100,193
Derivative assets, Netting adjustments	(333)	(443)
Derivative assets, Fair Value	529	664
Derivative liabilities, Netting adjustments	(337)	(616)
Derivative liabilities, Fair Value	353	207
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	28,668	26,478
Derivative assets, Fair Value	52	82
Derivative liabilities, Fair Value	(10)	50
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	73,977	73,715
Derivative assets, Fair Value	812	1,030
Derivative liabilities, Fair Value	733	857
Interest Rate [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	28,546	26,176
Derivative assets, Fair Value	50	81
Derivative liabilities, Fair Value	(10)	46
Interest Rate [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	63,454	61,390
Derivative assets, Fair Value	365	641
Derivative liabilities, Fair Value	307	474
Foreign Exchange Contract [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	122	302
Derivative assets, Fair Value	2	1
Derivative liabilities, Fair Value	0	4
Foreign Exchange Contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	6,829	8,317
Derivative assets, Fair Value	104	129
Derivative liabilities, Fair Value	95	120
Commodity [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	2,002	1,687
Derivative assets, Fair Value	333	255
Derivative liabilities, Fair Value	323	246
Credit [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	226	315
Derivative assets, Fair Value	1	1
Derivative liabilities, Fair Value	1	4
Other Credit Derivatives [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	1,466	2,006
Derivative assets, Fair Value	9	4
Derivative liabilities, Fair Value	7	13
Net Derivatives [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	102,645	100,193
Derivative assets, Fair Value	531	669
Derivative liabilities, Fair Value	386	291
Counterparty And Cash Collateral Netting [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	0	0
Derivative assets, Fair Value	(2)	(5)
Derivative liabilities, Fair Value	$ (33)	$ (84)

Derivatives and Hedging Activ_5

Derivatives and Hedging Activities - Cumulative Basis Adjustments on Fair Value Hedges (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Certificate of deposit ($100,000 or more)	$ 100,000	$ 100,000
Long-term Debt [Member] | Interest Rate [Member]
Derivatives, Fair Value [Line Items]
Carrying amount of hedged item	9,363,000,000
Hedge accounting basis adjustment	(6,000,000)
Certificates of Deposit [Member] | Interest Rate [Member]
Derivatives, Fair Value [Line Items]
Certificate of deposit ($100,000 or more)	100,000
Carrying amount of hedged item	343,000,000
Hedge accounting basis adjustment	(1,000,000)
Bank Time Deposits [Member] | Interest Rate [Member]
Derivatives, Fair Value [Line Items]
Carrying amount of hedged item	178,000,000
Hedge accounting basis adjustment	0
Not Designated as Hedging Instrument [Member] | Long-term Debt [Member] | Interest Rate [Member]
Derivatives, Fair Value [Line Items]
Hedge accounting basis adjustment	$ (10,000,000)

Derivatives and Hedging Activ_6

Derivatives and Hedging Activities - Effect of Fair Value and Cash Flow Hedges on Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense — Long-term debt		$ (420)	$ (319)	$ (218)
Interest income — Loans		4,023	3,677	2,773
Investment banking and debt placement fees		650	603	482
Deposits		(517)	(278)	(171)
Other income	[1]	176	153	114
Other Income [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Gains (losses) (before tax) recognized in income for hedge ineffectiveness			0	0
Interest Rate [Member] | Interest Expense, Long-Term Debt [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Recognized on hedged items		(5)	0	0
Recognized on derivatives designated as hedging instruments		(12)	49	96
Net income (expense) recognized on fair value hedges		(17)	49	96
Interest Rate [Member] | Interest Expense, Long-Term Debt [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income		(2)	(4)	(4)
Gains (losses) (before tax) recognized in income for hedge ineffectiveness			0	0
Net income (expense) recognized on cash flow hedges		(2)	(4)	(4)
Interest Rate [Member] | Interest Income [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Recognized on hedged items		0	0	0
Recognized on derivatives designated as hedging instruments		0	0	0
Net income (expense) recognized on fair value hedges		0	0	0
Interest Rate [Member] | Interest Income [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income		(68)	19	85
Gains (losses) (before tax) recognized in income for hedge ineffectiveness			0	0
Net income (expense) recognized on cash flow hedges		(68)	19	85
Interest Rate [Member] | Investment Banking And Debt Placement [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Recognized on hedged items		0	0	0
Recognized on derivatives designated as hedging instruments		0	0	0
Net income (expense) recognized on fair value hedges		0	0	0
Interest Rate [Member] | Investment Banking And Debt Placement [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income		2	0	0
Gains (losses) (before tax) recognized in income for hedge ineffectiveness			0	0
Net income (expense) recognized on cash flow hedges		2	0	0
Interest Rate [Member] | Interest Expense, Deposits [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Recognized on hedged items		1	0	0
Recognized on derivatives designated as hedging instruments		0	0	0
Net income (expense) recognized on fair value hedges		1	0	0
Interest Rate [Member] | Interest Expense, Deposits [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income		0	0	0
Gains (losses) (before tax) recognized in income for hedge ineffectiveness			0	0
Net income (expense) recognized on cash flow hedges		0	0	0
Interest Rate [Member] | Other Income [Member] | Fair Value Hedging [Member]
Gain (Loss) on Fair Value Hedges Recognized in Earnings [Abstract]
Recognized on hedged items		0	107	97
Recognized on derivatives designated as hedging instruments		0	(103)	(95)
Net income (expense) recognized on fair value hedges		0	4	2
Interest Rate [Member] | Other Income [Member] | Cash Flow Hedging [Member]
Cash Flow Hedges Derivative Instruments at Fair Value, Net [Abstract]
Realized gains (losses) (pre-tax) reclassified from AOCI into net income		31	0	0
Net income (expense) recognized on cash flow hedges		$ 31	$ 0	$ 0
[1]	Net securities gains (losses) totaled less than $1 million for each of the years ended December 31, 2018 , 2017 , and 2016 . For 2018 , 2017 , and 2016

Derivatives and Hedging Activ_7

Derivatives and Hedging Activities - Derivative Instrument Cash Flow Hedge Earning Recognized by Income Statement Location (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	$ 9,000,000	$ (77,000,000)	$ 28,000,000
Net Gains (Losses) Reclassified From OCI Into Income	(37,000,000)	15,000,000	81,000,000
Net Gains (Losses) Recognized in Other Income(a)	0	0	0
Interest Income [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	(13,000,000)	(59,000,000)	29,000,000
Net Gains (Losses) Reclassified From OCI Into Income	(68,000,000)	19,000,000	85,000,000
Net Gains (Losses) Recognized in Other Income(a)	0	0	0
Interest Expense [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	2,000,000	0	0
Net Gains (Losses) Reclassified From OCI Into Income	(2,000,000)	(4,000,000)	(4,000,000)
Net Gains (Losses) Recognized in Other Income(a)	0	0	0
Underwriting Discounts Fees And Commissions [Member] | Interest Rate [Member] | Cash Flow Hedges [Member]
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	1,000,000	(1,000,000)	1,000,000
Net Gains (Losses) Reclassified From OCI Into Income	2,000,000	0	0
Net Gains (Losses) Recognized in Other Income(a)	0	0	0
Other Income [Member] | Foreign Exchange Contract [Member] | Net Investment Hedges [Member]
Derivatives, Fair Value [Line Items]
Net Gains (Losses) Recognized in OCI	19,000,000	(17,000,000)	(2,000,000)
Net Gains (Losses) Reclassified From OCI Into Income	31,000,000	0	0
Net Gains (Losses) Recognized in Other Income(a)	$ 0	$ 0	$ 0

Derivatives and Hedging Activ_8

Derivatives and Hedging Activities - Pre-Tax Net Gains (Losses) on Derivatives Not Designated as Hedging Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	$ 70	$ 49	$ 61
Interest Rate [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	37	28	31
Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	42	41	40
Commodity [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	8	6	4
Credit [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(28)	(19)	(15)
Other Credit Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	11	(7)	1
Corporate Services Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	90	78	75
Corporate Services Income [Member] | Interest Rate [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	38	29	30
Corporate Services Income [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	42	41	40
Corporate Services Income [Member] | Commodity [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	8	6	4
Corporate Services Income [Member] | Credit [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	2	2	1
Corporate Services Income [Member] | Other Credit Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Consumer Mortgage Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(1)	(1)	1
Consumer Mortgage Income [Member] | Interest Rate [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Consumer Mortgage Income [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Consumer Mortgage Income [Member] | Commodity [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Consumer Mortgage Income [Member] | Credit [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Consumer Mortgage Income [Member] | Other Credit Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(1)	(1)	1
Other Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(19)	(28)	(15)
Other Income [Member] | Interest Rate [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(1)	(1)	1
Other Income [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Other Income [Member] | Commodity [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	0	0	0
Other Income [Member] | Credit [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	(30)	(21)	(16)
Other Income [Member] | Other Credit Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total net gains (losses)	$ 12	$ (6)	$ 0

Derivatives and Hedging Activ_9

Derivatives and Hedging Activities - Fair Value of Derivative Assets by Type (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Credit Derivatives [Line Items]
Derivative assets before collateral	$ 564	$ 646
Less: Related collateral	33	(23)
Total derivative assets	531	669
Interest Rate [Member]
Credit Derivatives [Line Items]
Derivative assets before collateral	308	401
Foreign Exchange Contract [Member]
Credit Derivatives [Line Items]
Derivative assets before collateral	60	77
Commodity [Member]
Credit Derivatives [Line Items]
Derivative assets before collateral	187	163
Credit [Member]
Credit Derivatives [Line Items]
Derivative assets before collateral	0	1
Other Credit Derivatives [Member]
Credit Derivatives [Line Items]
Derivative assets before collateral	$ 9	$ 4

Derivatives and Hedging Acti_10

Derivatives and Hedging Activities - Credit Derivatives Sold and Held (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Credit Derivatives [Line Items]
Notional Amount	$ 22	$ 15
Average Term (Years)	0 years	0 years
Payment / Performance Risk	0.00%	0.00%
Other [Member]
Credit Derivatives [Line Items]
Notional Amount	$ 22	$ 15
Average Term (Years)	13 years 5 months 4 days	3 years 29 days
Payment / Performance Risk	17.18%	6.64%

Derivatives and Hedging Acti_11

Derivatives and Hedging Activities - Credit Risk Contingent Feature (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	$ 4
Moody's, A3 Rating [Member] | One Rating Downgrade [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	2	$ 2
Moody's, A3 Rating [Member] | Two Rating Downgrades [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	2	2
Moody's, A3 Rating [Member] | Three Rating Downgrades [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	2	2
Standard & Poor's, A- Rating [Member] | One Rating Downgrade [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	2	2
Standard & Poor's, A- Rating [Member] | Two Rating Downgrades [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	2	2
Standard & Poor's, A- Rating [Member] | Three Rating Downgrades [Member]
Credit Derivatives [Line Items]
Additional collateral aggregate fair value	$ 2	$ 2

Mortgage Servicing Assets - Cha

Mortgage Servicing Assets - Changes in Carrying Amount of Mortgage Servicing Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Commercial Mortgage Backed Securities [Member]
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	$ 412	$ 356
Servicing retained from loan sales	117	110
Purchases	75	36
Amortization	(102)	(90)
Balance at end of period	502	412
Fair value at end of period	757	537
Residential Mortgage Backed Securities [Member]
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	31	28
Servicing retained from loan sales	10	7
Purchases	0	0
Amortization	(4)	(4)
Balance at end of period	37	31
Fair value at end of period	$ 52	$ 37

Mortgage Servicing Assets - Sch

Mortgage Servicing Assets - Schedule of Range and Weighted-Average of Significant Unobservable Inputs (Details) - Discounted Cash Flow [Member] - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Commercial Mortgage Backed Securities [Member] | Minimum [Member]
Servicing Assets at Fair Value [Line Items]
Expected defaults/Discount rate (as a percent)	1.00%	1.00%
Residual cash flows discount rate (as a percent)	7.00%	7.00%
Escrow earn rate (as a percent)	2.56%	0.90%
Loan assumption rate (as a percent)	0.00%	0.00%
Commercial Mortgage Backed Securities [Member] | Maximum [Member]
Servicing Assets at Fair Value [Line Items]
Expected defaults/Discount rate (as a percent)	2.00%	3.00%
Residual cash flows discount rate (as a percent)	15.00%	15.00%
Escrow earn rate (as a percent)	4.20%	3.10%
Loan assumption rate (as a percent)	3.22%	3.00%
Commercial Mortgage Backed Securities [Member] | Weighted Average [Member]
Servicing Assets at Fair Value [Line Items]
Expected defaults/Discount rate (as a percent)	1.14%	1.20%
Residual cash flows discount rate (as a percent)	9.18%	9.10%
Escrow earn rate (as a percent)	3.35%	2.50%
Loan assumption rate (as a percent)	1.35%	1.22%
Residential Mortgage Backed Securities [Member] | Minimum [Member]
Servicing Assets at Fair Value [Line Items]
Expected defaults/Discount rate (as a percent)	7.50%	8.50%
Prepayment speed (as a percent)	8.45%	9.16%
Servicing cost	$ 62,000,000	$ 76,000,000
Residential Mortgage Backed Securities [Member] | Maximum [Member]
Servicing Assets at Fair Value [Line Items]
Expected defaults/Discount rate (as a percent)	10.00%	11.00%
Prepayment speed (as a percent)	56.11%	51.52%
Servicing cost	$ 5,125,000,000	$ 4,385,000,000
Residential Mortgage Backed Securities [Member] | Weighted Average [Member]
Servicing Assets at Fair Value [Line Items]
Expected defaults/Discount rate (as a percent)	7.54%	8.54%
Prepayment speed (as a percent)	9.08%	10.46%
Servicing cost	$ 68,250,000	$ 83,110,000

Mortgage Servicing Assets - Nar

Mortgage Servicing Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commercial Mortgage Backed Securities [Member]
Servicing Assets at Fair Value [Line Items]
Contractual fee income	$ 171	$ 150	$ 139
Amortization of mortgage servicing rights	102	$ 90	$ 87
Residential Mortgage Backed Securities [Member]
Servicing Assets at Fair Value [Line Items]
Contractual fee income	14
Amortization of mortgage servicing rights	$ 4

Premises and Equipment - Schedu

Premises and Equipment - Schedule of Premises and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 2,478	$ 2,508
Less: Accumulated depreciation and amortization	(1,596)	(1,578)
Premises and equipment, net	882	930
Land
Property, Plant and Equipment [Line Items]
Total premises and equipment	135	138
Buildings and improvements
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 747	741
Buildings and improvements | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	15 years
Buildings and improvements | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	40 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 626	633
Leasehold improvements | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Leasehold improvements | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	15 years
Furniture and equipment
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 907	931
Furniture and equipment | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	2 years
Furniture and equipment | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	15 years
Capitalized building leases
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 28	27
Capitalized building leases | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Capitalized building leases | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)	15 years
Construction in process
Property, Plant and Equipment [Line Items]
Total premises and equipment	$ 35	$ 38

Premises and Equipment - Narrat

Premises and Equipment - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 129	$ 138	$ 123

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Oct. 02, 2017	Sep. 30, 2017	Jul. 01, 2017	Jun. 30, 2017	Dec. 31, 2016
Goodwill [Line Items]
Expected deductible goodwill for tax purpose	$ 540,000,000
Key Merchant Services, LLC [Member]
Goodwill [Line Items]
Intangible assets acquired				$ 85,000,000		$ 95,000,000
HelloWallet Holdings, LLC [Member]
Goodwill [Line Items]
Intangible assets acquired					$ 12,000,000
Cain Brothers & Company, LLC. [Member]
Goodwill [Line Items]
Intangible assets acquired			$ 30,000,000
Key Community Bank Unit [Member]
Goodwill [Line Items]
Estimated fair value of the Community Bank unit greater than certain percent of carrying value	48.00%
Accumulated impairment loss	$ 0	$ 0					$ 0
Key Corporate Bank [Member]
Goodwill [Line Items]
Estimated fair value of the Community Bank unit greater than certain percent of carrying value	39.00%
Accumulated impairment loss	$ 0	$ 0					$ 0
Customer Relationships [Member] | Key Merchant Services, LLC [Member]
Goodwill [Line Items]
Useful life of intangible assets	10 years
Customer Relationships [Member] | Cain Brothers & Company, LLC. [Member]
Goodwill [Line Items]
Useful life of intangible assets	8 years
Proprietary Software [Member] | HelloWallet Holdings, LLC [Member]
Goodwill [Line Items]
Useful life of intangible assets	3 years
Trade Names [Member] | Cain Brothers & Company, LLC. [Member]
Goodwill [Line Items]
Useful life of intangible assets	3 years

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Beginning Balance	$ 2,538	$ 2,446
KIBS divestiture	(22)
Ending Balance	2,516	2,538
Key Community Bank [Member]
Goodwill [Roll Forward]
Beginning Balance	2,124	2,088
KIBS divestiture	(22)
Ending Balance	2,102	2,124
Key Corporate Bank [Member]
Goodwill [Roll Forward]
Beginning Balance	414	358
KIBS divestiture	0
Ending Balance	$ 414	414
First Niagara Bank, N.A. [Member]
Goodwill [Roll Forward]
Fair value measurement adjustments - First Niagara acquisition		18
First Niagara Bank, N.A. [Member] | Key Community Bank [Member]
Goodwill [Roll Forward]
Fair value measurement adjustments - First Niagara acquisition		15
First Niagara Bank, N.A. [Member] | Key Corporate Bank [Member]
Goodwill [Roll Forward]
Fair value measurement adjustments - First Niagara acquisition		3
Key Merchant Services, LLC [Member]
Goodwill [Roll Forward]
Fair value measurement adjustments - First Niagara acquisition		4
Additional ownership interest in Key Merchant Services		4
Key Merchant Services, LLC [Member] | Key Community Bank [Member]
Goodwill [Roll Forward]
Additional ownership interest in Key Merchant Services		4
Key Merchant Services, LLC [Member] | Key Corporate Bank [Member]
Goodwill [Roll Forward]
Additional ownership interest in Key Merchant Services		0
HelloWallet Holdings, LLC [Member]
Goodwill [Roll Forward]
Goodwill, acquired during period		17
HelloWallet Holdings, LLC [Member] | Key Community Bank [Member]
Goodwill [Roll Forward]
Goodwill, acquired during period		17
HelloWallet Holdings, LLC [Member] | Key Corporate Bank [Member]
Goodwill [Roll Forward]
Goodwill, acquired during period		0
Cain Brothers & Company, LLC. [Member]
Goodwill [Roll Forward]
Goodwill, acquired during period		53
Cain Brothers & Company, LLC. [Member] | Key Community Bank [Member]
Goodwill [Roll Forward]
Goodwill, acquired during period		0
Cain Brothers & Company, LLC. [Member] | Key Corporate Bank [Member]
Goodwill [Roll Forward]
Goodwill, acquired during period		$ 53

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Gross Carrying Amount and Accumulated Amortization of Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Gross Carrying Amount	$ 663	$ 741
Accumulated Amortization	347	325
Core Deposit Intangibles [Member]
Goodwill [Line Items]
Gross Carrying Amount	396	461
Accumulated Amortization	184	192
Purchased Credit Card Relationship Intangible [Member]
Goodwill [Line Items]
Gross Carrying Amount	152	152
Accumulated Amortization	138	126
Other Intangible Assets [Member]
Goodwill [Line Items]
Gross Carrying Amount	115	128
Accumulated Amortization	$ 25	$ 7

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Schedule of Intangible Assets Acquired (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	$ 127
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	114
Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	1
Proprietary Software [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	12
Key Merchant Services, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	85
Key Merchant Services, LLC [Member] | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	85
Key Merchant Services, LLC [Member] | Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	0
Key Merchant Services, LLC [Member] | Proprietary Software [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	0
HelloWallet Holdings, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	12
HelloWallet Holdings, LLC [Member] | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	0
HelloWallet Holdings, LLC [Member] | Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	0
HelloWallet Holdings, LLC [Member] | Proprietary Software [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	12
Cain Brothers & Company, LLC. [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	30
Cain Brothers & Company, LLC. [Member] | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	29
Cain Brothers & Company, LLC. [Member] | Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	1
Cain Brothers & Company, LLC. [Member] | Proprietary Software [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets acquired, subject to amortization	$ 0

Goodwill and Other Intangible_7

Goodwill and Other Intangible Assets - Future Amortization Expense of Finite-Lived Intangible Assets (Details) $ in Millions	Dec. 31, 2018USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,019	$ 80
2,020	62
2,021	52
2,022	42
2,023	$ 34

Variable Interest Entities - Na

Variable Interest Entities - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Investments in LIHTC operating partnerships	$ 248,000,000	$ 230,000,000
Total Liabilities	2,000,000	4,000,000
Impairment expense related to tax reform	168,000,000
Other expense	460,000,000	558,000,000	$ 530,000,000
LIHTC Investments [Member]
Variable Interest Entity [Line Items]
Investments in LIHTC operating partnerships	5,932,000,000	6,003,000,000
Total Liabilities	2,569,000,000	2,943,000,000
LIHTC Investments [Member] | Qualified affordable housing projects investment [Member]
Variable Interest Entity [Line Items]
Total Liabilities	532,000,000	476,000,000
Accrued Income And Other Assets [Member] | LIHTC Investments [Member]
Variable Interest Entity [Line Items]
Investments in LIHTC operating partnerships	1,400,000,000	1,300,000,000
Investments [Member] | LIHTC Investments [Member]
Variable Interest Entity [Line Items]
Amortization of investment	170,000,000	172,000,000
Tax credit of investment	166,000,000	171,000,000
Impairment expense related to tax reform		12,000,000
Other expense		3,000,000
Investments [Member] | Guaranteed Funds [Member]
Variable Interest Entity [Line Items]
Assets that can only be used to settle entities' obligations	0	4,000,000
Variable interest entity, liabilities	0	0
Fair Value, Measurements, Recurring [Member]
Variable Interest Entity [Line Items]
Other investments	$ 115,000,000	$ 144,000,000

Variable Interest Entities - Va

Variable Interest Entities - Variable Interest Entities Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Total Assets	$ 248	$ 230
Total Liabilities	2	4
LIHTC Investments [Member]
Variable Interest Entity [Line Items]
Total Assets	5,932	6,003
Total Liabilities	2,569	2,943
Maximum Exposure to Loss	1,740	1,561
KCC Indirect Investments [Member]
Variable Interest Entity [Line Items]
Total Assets	19,659	26,817
Total Liabilities	376	292
Maximum Exposure to Loss	$ 122	$ 153

Income Taxes - Income Taxes Inc

Income Taxes - Income Taxes Included in Income Statement (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Currently payable:
Federal	$ 184,000,000	$ 334,000,000	$ 149,000,000
State	62,000,000	0	19,000,000
Total currently payable	246,000,000	334,000,000	168,000,000
Deferred:
Federal	117,000,000	274,000,000	13,000,000
State	(19,000,000)	29,000,000	(2,000,000)
Total deferred	98,000,000	303,000,000	11,000,000
Total income tax expense (benefit)	344,000,000	637,000,000	179,000,000
Income tax (benefit) expense on securities transactions	0	0	0
Equity and gross receipts based taxes assessed in lieu of income tax recorded in noninterest expense	$ 15,000,000	$ 22,000,000	$ 18,000,000

Income Taxes - Significant Comp

Income Taxes - Significant Components of Deferred Tax Assets and Liabilities Included in "Accrued Income and Other Assets" and "Accrued Expense and Other Liabilities" (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Allowance for loan and lease losses	$ 232	$ 233
Employee benefits	170	147
Net unrealized securities losses	144	138
Federal net operating losses and credits	34	205
Fair value adjustments	41	63
Non-tax accruals	80	89
State net operating losses and credits	3	7
Other	221	223
Gross deferred tax assets	925	1,105
Less: Valuation Allowance	11	15
Total deferred tax assets	914	1,090
Leasing transactions	531	588
Other	161	182
Total deferred tax liabilities	692	770
Net deferred tax assets (liabilities)	$ 222	$ 320

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Tax reform, provisional income tax expense				$ 161,000,000
Tax reform, provisional income tax expense, low-income housing investments				14,000,000
Tax reform, change in tax rate, provisional income tax expense				$ 147,000,000
Tax reform, change in enacted tax rate, percent				7.60%
Tax reform, measurement period adjustment	$ 7,000,000
Tax reform, total impact			$ 168,000,000
Reclassification of tax effects in AOCI resulting from the new federal corporate income tax rate		$ 141,000,000		$ (141,000,000)
Less: Valuation Allowance		15,000,000	11,000,000	15,000,000
Credit carryforward		205,000,000	34,000,000	205,000,000
Deferred tax asset		1,090,000,000	914,000,000	1,090,000,000
Unrecognized tax benefits		39,000,000	35,000,000	39,000,000	$ 53,000,000
Net interest expenses (credits)			(700,000)	(1,300,000)	(400,000)
Recovery of penalties related to unrecognized tax benefits in income tax expense		1,000,000	0	1,000,000	$ 0
Accrued interest payable		4,000,000	3,000,000	4,000,000
Accrued state tax penalties		$ 0	0	0
Reduction in federal tax credit carryforward			14,300,000	$ 17,200,000
Maximum [Member]
Income Taxes [Line Items]
Less: Valuation Allowance			11,000,000
Federal [Member]
Income Taxes [Line Items]
Federal net operating loss carryforwards			61,000,000
Credit carryforward			21,000,000
State [Member]
Income Taxes [Line Items]
Credit carryforward			1,000,000
State net operating loss carryforwards			54,000,000
Deferred tax asset			3,000,000
Capital loss carryforwards			1,000,000
First Niagara Bank, N.A. [Member]
Income Taxes [Line Items]
Allocated bad debt deductions for which no income taxes have been recorded			92,000,000
Capital Loss Carryforward [Member]
Income Taxes [Line Items]
Tax credit carryforward			$ 11,000,000

Income Taxes - Total Income Tax

Income Taxes - Total Income Tax Expense (Benefit) and Resulting Effective Tax Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income (loss) before income taxes times 21% (35% for 2017 and 2016) statutory federal tax rate	$ 463	$ 675	$ 339
Amortization of tax-advantaged investments	127	104	88
Foreign tax adjustments	2	1	1
Tax-exempt interest income	(30)	(37)	(25)
Corporate-owned life insurance income	(29)	(46)	(44)
State income tax, net of federal tax benefit	34	19	11
Tax credits	(234)	(218)	(208)
Tax Cuts and Jobs Act	7	147	0
Other	4	(8)	17
Total income tax expense (benefit)	$ 344	$ 637	$ 179
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal income tax rate	21.00%	35.00%	35.00%
Amortization of tax-advantaged investments (as a percent)	5.80%	5.40%	9.00%
Foreign tax adjustments (as a percent)	0.10%	0.10%	0.10%
Tax-exempt interest income (as a percent)	(1.40%)	(1.90%)	(2.60%)
Corporate-owned life insurance income (as a percent)	(1.30%)	(2.40%)	(4.50%)
State income tax, net of federal tax benefit (as a percent)	1.50%	1.00%	1.10%
Tax credits (as a percent)	(10.60%)	(11.30%)	(21.30%)
Tax Cuts and Jobs Act (as a percent)	0.30%	7.60%	0.00%
Other (as a percent)	0.20%	(0.50%)	1.70%
Total income tax expense (benefit) (as a percent)	15.60%	33.00%	18.50%

Income Taxes - Change in Liabil

Income Taxes - Change in Liability for Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 39	$ 53
Increase for other tax positions of prior years	15	3
Increase from Acquisitions	0	3
Decrease for payments and settlements	0	(4)
Decrease related to tax positions taken in prior years	(19)	(16)
Balance at end of year	$ 35	$ 39

Acquisition, Divestiture, and_2

Acquisition, Divestiture, and Discontinued Operations - Narrative (Details) $ in Millions	May 04, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 29, 2017USD ($)	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jan. 16, 2019Branch	Oct. 02, 2017USD ($)	Jul. 01, 2017USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill					$ 2,538		$ 2,516	$ 2,538	$ 2,446
Gain on sale							83	0	$ 0
Cain Brothers & Company, LLC. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other intangible assets											$ 30
Goodwill											$ 53
HelloWallet Holdings, LLC [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other intangible assets												$ 12
Goodwill												$ 17
Key Merchant Services, LLC [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other intangible assets		$ 95				$ 85
Goodwill		$ 1
Business acquisition, percentage of voting interests acquired		51.00%
Business combination, percentage held before acquisition date			49.00%
Business combination, ownership percentage		100.00%
Exchange of First Niagara preferred stock for KeyCorp preferred stock			$ 74			69
Business combination, estimated fair value of equity interest						5
Business combination, noncash holding gain		$ 64				59
Measurement-period adjustment, intangible assets						$ 10
Reduction to goodwill, subsequent recognition of deferred tax asset					2
Tax adjustment on previous fair value measurements								4
Disposal Group, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale	$ 73			$ 5
Discontinued Operations [Member] | Government Guaranteed Loans [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans included in divestiture					$ 1,300		$ 1,100	$ 1,300
Subsequent Event [Member] | Laurel Road Bank [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of bank branches excluded from transaction | Branch										3

Securities Financing Activiti_3

Securities Financing Activities - Summarized Securities Financing Agreements (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Securities Financing Transaction [Line Items]
Reverse repurchase agreements	$ 0	$ 0
Total offsetting of financial assets	0	0
Repurchase agreements	0	0
Total offsetting of financial liabilities	0	0
Counterparty And Cash Collateral Netting [Member]
Securities Financing Transaction [Line Items]
Reverse repurchase agreements	0	0
Total offsetting of financial assets	0	0
Repurchase agreements	(305)	(370)
Total offsetting of financial liabilities	(305)	(370)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities Financing Transaction [Line Items]
Carrying amount of assets pledged as collateral against repurchase agreements	892
Liabilities associated with collateral pledged	304
Gross Amount Presented in Balance Sheet [Member]
Securities Financing Transaction [Line Items]
Reverse repurchase agreements	14	3
Total offsetting of financial assets	14	3
Repurchase agreements	319	374
Total offsetting of financial liabilities	319	374
Netting Adjustments [Member]
Securities Financing Transaction [Line Items]
Reverse repurchase agreements	(14)	(3)
Total offsetting of financial assets	(14)	(3)
Repurchase agreements	(14)	(4)
Total offsetting of financial liabilities	$ (14)	$ (4)

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total compensation expense for stock-based compensation plans	$ 99,000,000	$ 104,000,000	$ 102,000,000
Total income tax benefit recognized for stock-based compensation plans	$ 23,000,000	$ 39,000,000	$ 38,000,000
Common Shares available for future grant under compensation plans (in shares)	24,147,422
Maximum percentage of outstanding common stock that may be granted as options	6.00%
Rolling period in which a certain percentage of common stock cannot be granted as options	3 years
Exercise rate of stock options granted to employees	25.00%
Vesting period for compensation cost	4 years
Common shares, shares issued (in shares)	1,256,702,081	1,256,702,081
Weighted-average grant-date fair value of options (in dollars per share)	$ 5.12	$ 4.6	$ 2.14
Number of options, exercised (in shares)	1,960,444
Total intrinsic value of exercised options	$ 21,000,000	$ 31,000,000	$ 12,000,000
Cash received from options exercised	20,000,000	25,000,000	32,000,000
Actual tax benefit realized for tax deductions from options exercised	$ 1,000,000	$ 4,000,000	$ 2,000,000
Mandatory deferred incentive awards, vesting rate (as a percent)	25.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares, shares issued (in shares)	3,000,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options expiration years	10 years
Number of options, exercised (in shares)	1,960,444	3,755,177	2,849,010
Unrecognized compensation cost related to nonvested options expected to vest	$ 2,000,000
Weighted-average period	2 years
Stock Options [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for compensation cost	1 year
Stock Options [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options expiration years	10 years
Deferred Cash Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Restricted Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Equity Based Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Cash Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Deferred Compensation Plans and Other Restricted Stock Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair value granted (in dollars per share)	$ 20.77	$ 18.55	$ 11.46
Deferred Compensation Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested options expected to vest	$ 21,000,000
Weighted-average period	2 years 10 months 24 days
Fair value of units/shares vested	$ 22,000,000	$ 21,000,000	$ 16,000,000
Long-Term Incentive Compensation Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested options expected to vest	$ 73,000,000
Weighted-average period	2 years 4 months 24 days
Number of performance units vested (in shares)	1,070,112	887,489
Fair value of units/shares vested	$ 93,000,000	$ 76,000,000	$ 57,000,000
Weighted-average grant-date fair value granted (in dollars per share)	$ 19.28	$ 19.82	$ 10.49
Long-Term Incentive Compensation Program [Member] | Performance Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of units/shares vested	$ 19,000,000	$ 14,000,000
Discounted Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee discount on the purchase of stock through Discounted Stock Purchase Plan	10.00%
Purchases are limited to any month	$ 10,000
Purchases are limited to any calendar year	$ 50,000
Issuance of common shares (in shares)	327,435	257,738	310,604
Weighted-average cost of common shares issued under the plan (in dollars per share)	17.48	16.61	11.04

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions Used in Options Pricing Model (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Average option life	6 years 6 months	6 years	6 years
Future dividend yield (as a percentage)	2.28%	1.79%	2.86%
Historical share price volatility (as a percentage)	0.282%	0.287%	0.297%
Weighted-average risk-free interest rate (as a percentage)	2.80%	2.10%	1.30%

Stock-Based Compensation - Acti

Stock-Based Compensation - Activity, Pricing and Other Information for Stock Options (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Options Outstanding, Beginning Balance (in shares)	9,882,617
Granted, Number of Options (in shares)	346,088
Exercised, Number of Options (in shares)	(1,960,444)
Lapsed or canceled, Number of Options (in shares)	(144,417)
Number of Options Outstanding, Ending Balance (in shares)	8,123,844	9,882,617
Expected to vest, Number of Options (in shares)	2,508,684
Number of Options Exercisable, Ending Balance (in shares)	5,479,638
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted-Average Exercise Price Per Option Outstanding, Beginning Balance (in dollars per share)	$ 11.28
Granted, Weighted-Average Exercise Price Per Option (in dollars per share)	21.02
Exercised, Weighted-Average Exercise Price Per Option (in dollars per share)	10.12
Lapsed or canceled, Weighted-Average Exercise Price Per Option (in dollars per share)	14.37
Weighted-Average Exercise Price Per Option Outstanding, Ending Balance (in dollars per share)	11.92	$ 11.28
Expected to vest, Weighted-Average Exercise Price Per Option (in dollars per share)	15.09
Weighted-Average Exercise Price Per Option Exercisable, Ending Balance (in dollars per share)	$ 10.36
Weighted-Average Remaining Life (Years) Outstanding	5 years 3 months 18 days	5 years 6 months
Expected to vest, Weighted-Average Remaining Life (Years)	7 years 7 months 6 days
Weighted-Average Remaining Life (Years) Exercisable	4 years 2 months 12 days
Aggregate Intrinsic Value Outstanding	$ 31	$ 88
Expected to vest, Aggregate Intrinsic Value	5
Aggregate Intrinsic Value Exercisable	$ 26

Stock-Based Compensation - Ac_2

Stock-Based Compensation - Activity and Pricing Information for Nonvested Shares in Long-Term Incentive Compensation Program (Details) - Long-Term Incentive Compensation Program [Member]	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Vesting Contingent on Service Conditions [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Nonvested Shares Outstanding, Beginning Balance (in shares) | shares	11,832,956
Number of Nonvested Shares, Granted (in shares) | shares	4,076,746
Number of Nonvested Shares, Vested (in shares) | shares	(5,404,616)
Number of Nonvested Shares, Forfeited (in shares) | shares	(930,136)
Number of Nonvested Shares Outstanding, Ending Balance (in shares) | shares	9,574,950
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant-Date Fair Value Outstanding, Beginning Balance (in dollars per share) | $ / shares	$ 14.05
Weighted-Average Grant-Date Fair Value, Granted (in dollars per share) | $ / shares	21.02
Weighted-Average Grant-Date Fair Value, Vested (in dollars per share) | $ / shares	13.61
Weighted-Average Grant-Date Fair Value, Forfeited (in dollars per share) | $ / shares	17.01
Weighted-Average Grant-Date Fair Value Outstanding, Ending Balance (in dollars per share) | $ / shares	$ 16.84
Vesting Contingent on Performance and Service Conditions [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Nonvested Shares Outstanding, Beginning Balance (in shares) | shares	4,148,020
Number of Nonvested Shares, Granted (in shares) | shares	1,588,738
Number of Nonvested Shares, Vested (in shares) | shares	(1,070,112)
Number of Nonvested Shares, Forfeited (in shares) | shares	(127,191)
Number of Nonvested Shares Outstanding, Ending Balance (in shares) | shares	4,539,455
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant-Date Fair Value Outstanding, Beginning Balance (in dollars per share) | $ / shares	$ 17.51
Weighted-Average Grant-Date Fair Value, Granted (in dollars per share) | $ / shares	14.83
Weighted-Average Grant-Date Fair Value, Vested (in dollars per share) | $ / shares	17.73
Weighted-Average Grant-Date Fair Value, Forfeited (in dollars per share) | $ / shares	19.42
Weighted-Average Grant-Date Fair Value Outstanding, Ending Balance (in dollars per share) | $ / shares	$ 14.35

Stock-Based Compensation - Ac_3

Stock-Based Compensation - Activity and Pricing Information for Nonvested Shares Granted Under Deferred Compensation Plans and Other Restricted Stock Awards (Details) - Deferred Compensation Plans and Other Restricted Stock Award [Member] - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Nonvested Shares Outstanding, Beginning Balance (in shares)	4,223,774
Number of Nonvested Shares, Granted (in shares)	724,287
Number of Nonvested Shares, Dividend Equivalents (in shares)	18
Number of Nonvested Shares, Vested (in shares)	(1,523,387)
Number of Nonvested Shares, Forfeited (in shares)	(144,875)
Number of Nonvested Shares Outstanding, Ending Balance (in shares)	3,279,817	4,223,774
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-Average Grant-Date Fair Value Outstanding, Beginning Balance (in dollars per share)	$ 15.61
Weighted-Average Grant Date Fair Value, Granted (in dollars per share)	20.77	$ 18.55	$ 11.46
Weighted-Average Grant Date Fair Value, Dividend Equivalents (in dollars per share)	20.03
Weighted-Average Grant-Date Fair Value, Vested (in dollars per share)	14.43
Weighted-Average Grant-Date Fair Value, Forfeited (in dollars per share)	14.18
Weighted-Average Grant-Date Fair Value Outstanding, Ending Balance (in dollars per share)	$ 17.36	$ 15.61

Employee Benefits - Narrative (

Employee Benefits - Narrative (Details)	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016benefit_plan	Dec. 31, 2009benefit_plan
Defined Benefit Plan Disclosure [Line Items]
Pre-tax AOCI not yet recognized as net pension cost		$ 511,000,000	$ 525,000,000
Pre-tax accumulated other comprehensive loss expected to be recognized as net pension cost		13,000,000
Accumulated benefit obligation for all pension plans		$ 1,200,000,000	$ 1,300,000,000
Percentage increase or decrease in expected return on plan assets		0.25%
Estimated increase or decrease in net pension cost		$ 3,000,000
Percentage increase or decrease in assumed discount rate		0.25%
Estimated change in net pension cost due to discount rate		$ 1,000,000
Expected return on plan assets		4.75%	6.00%	6.00%
Expected return on plan assets on estimating 2013 pension cost		4.50%
Employer contribution to saving plan		6.00%
Annual increase to default employee contribution, percent		1.00%
Employer discretionary contribution, required service period		1 year
Employer discretionary contribution percentage		2.00%	2.00%	2.50%
Additional employer discretionary contribution amount, per full-time employee		$ 1,000
Additional employer discretionary contribution amount, per part-time employee		500
Additional employer discretionary contribution amount, salary requirement		100,000
Total expenses associated with saving plan		$ 106,000,000	$ 129,000,000	$ 94,000,000
Initial Default Percentage [Member]
Defined Benefit Plan Disclosure [Line Items]
Initial default employee contribution, percent		2.00%
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2019		$ 112,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2020		110,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2021		110,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2022		102,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2023		98,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2024 through 2028		400,000,000
Accumulated benefit obligation for all pension plans		1,201,000,000	1,323,000,000
Net pension cost (benefit)		$ 22,000,000	$ (5,000,000)	$ 21,000,000
Expected return on plan assets		4.75%	6.00%	6.00%
Discount rate		4.00%	3.25%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Pre-tax AOCI not yet recognized as net pension cost		$ (12,000,000)	$ (13,000,000)
Pre-tax accumulated other comprehensive loss expected to be recognized as net pension cost		1,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2019		5,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2020		5,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2021		5,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2022		5,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2023		5,000,000
Benefits expected to be paid from all funded and unfunded pension plans/other postretirement plans in 2024 through 2028		22,000,000
Net pension cost (benefit)		$ (1,000,000)	$ 1,000,000	$ 0
Expected return on plan assets		4.50%	4.50%	4.50%
Age of employees under condition one		55 years
Period of service under condition one		5 years
Age of employees under condition two		50 years
Period of service under condition two		15 years
Minimum period of service at the time of termination hired before 2001		15 years
Discount rate		4.00%	3.50%
First Niagara Bank, N.A. [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of plans | benefit_plan					2	2
Scenario, Forecast [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net pension cost (benefit)	$ 12,000,000
Scenario, Forecast [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net pension cost (benefit)	$ 0
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employees contribution to saving plan		1.00%
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Employees contribution to saving plan		100.00%
Default employee contribution, percent		10.00%

Employee Benefits - Net Pension

Employee Benefits - Net Pension Cost and Amount Recognized in OCI for All Funded and Unfunded Plans (Details) - Pension Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Interest cost on PBO	$ 41	$ 48	$ 44
Expected return on plan assets	(53)	(68)	(58)
Amortization of losses	17	15	17
Settlement loss	17	0	18
Net pension cost (benefit)	22	(5)	21
Other changes in plan assets and benefit obligations recognized in OCI:
Net (gain) loss	20	(10)	(9)
Amortization of gains	(33)	(15)	(35)
Total recognized in comprehensive income	(13)	(25)	(44)
Total recognized in net pension cost and comprehensive income	$ 9	$ (30)	$ (23)

Employee Benefits - Changes in

Employee Benefits - Changes in PBO Related to Pension Plans (Details) - Pension Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
PBO/APBO at beginning of year	$ 1,323	$ 1,338
Interest cost	41	48	$ 44
Actuarial losses (gains)	(66)	37
Benefit payments	(97)	(100)
PBO/APBO at end of year	$ 1,201	$ 1,323	$ 1,338

Employee Benefits - Changes i_2

Employee Benefits - Changes in FVA (Details) - Pension Plan [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
FVA at beginning of year	$ 1,163	$ 1,133
Actual return on plan assets	(34)	115
Employer contributions	14	15
Benefit payments	(97)	(100)
FVA at end of year	$ 1,046	$ 1,163

Employee Benefits - Funded Stat

Employee Benefits - Funded Status of Pension Plans Recognized in Balance Sheets (Details) - Pension Plan [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Funded status	$ (155)	$ (160)
Net prepaid pension cost recognized consists of:
Noncurrent assets	17	29
Current liabilities	(15)	(15)
Noncurrent liabilities	(157)	(174)
Net prepaid pension cost recognized	$ (155)	$ (160)

Employee Benefits - Plans ABO i

Employee Benefits - Plans ABO in Excess of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
ABO	$ 1,200	$ 1,300
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
PBO	1,201	1,323
ABO	1,201	1,323
Fair value of plan assets	$ 1,046	$ 1,163

Employee Benefits - Weighted-Av

Employee Benefits - Weighted-Average Rates to Determine Actuarial Present Value of Benefit Obligations (Details)	Dec. 31, 2018	Dec. 31, 2017
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.00%	3.25%

Employee Benefits - Weighted-_2

Employee Benefits - Weighted-Average Rates to Determine Net Pension Cost (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Discount rate	3.25%	3.75%	3.75%
Expected return on plan assets	4.75%	6.00%	6.00%

Employee Benefits - Asset Targe

Employee Benefits - Asset Target Allocations Prescribed by Pension Funds' Investment Policies (Details)	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	100.00%
Equity Securities, United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	5.00%
Equity Securities, International [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	4.00%
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	81.00%
Defined Benefit Plan, Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	6.00%
Other assets (measured at NAV) [Member]
Defined Benefit Plan Disclosure [Line Items]
Total Target Allocation	4.00%

Employee Benefits - Fair Values

Employee Benefits - Fair Values of Pension Plan Assets by Asset Category (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 1,046	$ 1,163	$ 1,133
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Government bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	2	2
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Common - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	6	11
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Common - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		1
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Preferred - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	3	3
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Corporate bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	157	152
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Corporate bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	65	61
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Government and agency bonds - U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	180	203
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | State and municpal bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	28	31
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Pension Plan [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	1	7
Level 1 [Member] | Government bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	10	22
Level 1 [Member] | Pension Plan [Member] | Common - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	6	11
Level 1 [Member] | Pension Plan [Member] | Common - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		1
Level 1 [Member] | Pension Plan [Member] | Preferred - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	3	3
Level 1 [Member] | Pension Plan [Member] | Corporate bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 [Member] | Pension Plan [Member] | Corporate bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 [Member] | Pension Plan [Member] | Government and agency bonds - U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 [Member] | Pension Plan [Member] | State and municpal bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 1 [Member] | Pension Plan [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	1	7
Level 2 [Member] | Government bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	2	2
Level 2 [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	432	449
Level 2 [Member] | Pension Plan [Member] | Common - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Pension Plan [Member] | Common - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Level 2 [Member] | Pension Plan [Member] | Preferred - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Pension Plan [Member] | Corporate bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	157	152
Level 2 [Member] | Pension Plan [Member] | Corporate bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	65	61
Level 2 [Member] | Pension Plan [Member] | Government and agency bonds - U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	180	203
Level 2 [Member] | Pension Plan [Member] | State and municpal bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	28	31
Level 2 [Member] | Pension Plan [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Government bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Common - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Common - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Level 3 [Member] | Pension Plan [Member] | Preferred - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Corporate bonds - US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Corporate bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Government and agency bonds - U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | State and municpal bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Pension Plan [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Fair Value Measured at Net Asset Value Per Share [Member] | Pension Plan [Member] | Collective Investment Funds (measured at NAV) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	546	628
Fair Value Measured at Net Asset Value Per Share [Member] | Pension Plan [Member] | Insurance investment contracts and pooled separate accounts (measured at NAV) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	16	14
Fair Value Measured at Net Asset Value Per Share [Member] | Pension Plan [Member] | Other assets (measured at NAV) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 42	$ 50

Employee Benefits - Pre-tax AOC

Employee Benefits - Pre-tax AOCI Not Yet Recognized as Net Postretirement Benefit Cost (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Total unrecognized AOCI	$ 511	$ 525
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net unrecognized losses (gains)	(12)	(12)
Net unrecognized prior service credit	0	(1)
Total unrecognized AOCI	$ (12)	$ (13)

Employee Benefits - Net Postret

Employee Benefits - Net Postretirement Benefit Cost and the Amount Recognized in OCI for All Funded and Unfunded Plans (Details) - Other Postretirement Benefit Plans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost of benefits earned	$ (1)	$ (1)	$ (1)
Interest cost on APBO	(2)	(3)	(2)
Expected return on plan assets	(2)	(2)	(2)
Amortization of prior service credit	(1)	(1)	(1)
Amortization of gains	(1)	0	0
Net pension cost (benefit)	(1)	1	0
Other changes in plan assets and benefit obligations recognized in OCI:
Net (gain) loss	1	(4)	(4)
Amortization of prior service credit	1	1	1
Amortization of losses	0	0	0
Total recognized in comprehensive income	2	(3)	(3)
Total recognized in net postretirement benefit cost and comprehensive income	$ 1	$ (2)	$ (3)

Employee Benefits - Changes i_3

Employee Benefits - Changes in APBO (Details) - Other Postretirement Benefit Plans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
PBO/APBO at beginning of year	$ 69	$ 69
Service cost	1	1	$ 1
Interest cost	2	3	2
Plan participants’ contributions	1	1
Actuarial losses (gains)	(6)	3
Benefit payments	(4)	(8)
PBO/APBO at end of year	$ 63	$ 69	$ 69

Employee Benefits - Change in F

Employee Benefits - Change in FVA (Other Post Retirement Benefit Plan Assets) (Details) - Other Postretirement Benefit Plans [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
FVA at beginning of year	$ 52	$ 50
Employer contributions	0	0
Plan participants’ contributions	1	1
Benefit payments	(4)	(8)
Actual return on plan assets	(2)	9
FVA at end of year	$ 47	$ 52

Employee Benefits - Funded St_2

Employee Benefits - Funded Status of Postretirement Plans Recognized in Balance Sheets (Details) - Other Postretirement Benefit Plans [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Funded status	$ (17)	$ (16)
Noncurrent liabilities	$ (17)	$ (16)

Employee Benefits - Weighted-_3

Employee Benefits - Weighted-Average Rates to Determine Net Postretirement Benefit Cost (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.25%	3.75%	3.75%
Expected return on plan assets	4.75%	6.00%	6.00%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.50%	3.75%	4.00%
Expected return on plan assets	4.50%	4.50%	4.50%

Employee Benefits - Asset Tar_2

Employee Benefits - Asset Target Allocations Prescribed by Trusts' Investment Policies (Details)	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	100.00%
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	100.00%
Equity Securities [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	80.00%
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	81.00%
Fixed Income Securities [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	20.00%
Defined Benefit Plan, Cash and Cash Equivalents [Member] | Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	0.00%

Employee Benefits - Fair Valu_2

Employee Benefits - Fair Values of Postretirement Plan Assets by Asset Category (Details) - Other Postretirement Benefit Plans [Member] - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 47	$ 52	$ 50
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Defined Benefit Plan, Mutual Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	21	25
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	8	10
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	7	4
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		3
Fair Value, Inputs, Level 1, 2 and 3 [Member] | Defined Benefit Plan, Collective Investment Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	9	10
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	36	42
Level 1 [Member] | Defined Benefit Plan, Mutual Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	21	25
Level 1 [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	8	10
Level 1 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	7	4
Level 1 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		3
Level 1 [Member] | Defined Benefit Plan, Collective Investment Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Defined Benefit Plan, Mutual Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 2 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Level 2 [Member] | Defined Benefit Plan, Collective Investment Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Defined Benefit Plan, Mutual Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Equity - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	0
Level 3 [Member] | Defined Benefit Plan, Mutual Funds, Fixed Income, Non-US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		0
Level 3 [Member] | Defined Benefit Plan, Collective Investment Funds, Equity, US [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	$ 0
Fair Value Measured at Net Asset Value Per Share [Member] | Other assets (measured at NAV) [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 2

Short-Term Borrowings - Compone

Short-Term Borrowings - Components of Short-Term Borrowings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Balance at year end, Securities Sold Under Repurchase Agreements	$ 0	$ 0
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Balance at year end, Federal Funds Purchase	0	3	$ 1,005
Average during the year	537	128	44
Maximum month-end balance	$ 3,197	$ 2,331	$ 1,005
Weighted-average rate during the year	1.68%	0.72%	0.68%
Weighted-average rate at December 31	0.00%	0.00%	0.55%
Securities Sold under Agreements to Repurchase [Member]
Short-term Debt [Line Items]
Average during the year	$ 391	$ 389	$ 443
Maximum month-end balance	$ 614	$ 472	$ 684
Weighted-average rate during the year	0.09%	0.08%	0.04%
Weighted-average rate at December 31	0.09%	0.08%	0.07%
Balance at year end, Securities Sold Under Repurchase Agreements	$ 319	$ 374	$ 497
Other Short Term Borrowings [Member]
Short-term Debt [Line Items]
Average during the year	915	1,140	852
Maximum month-end balance	$ 1,133	$ 1,242	$ 872
Weighted-average rate during the year	2.34%	1.34%	1.18%
Weighted-average rate at December 31	2.92%	2.01%	1.11%
Balance at year end, Other Short-Term Borrowings	$ 544	$ 634	$ 808

Short-Term Borrowings - Narrati

Short-Term Borrowings - Narrative (Details) $ in Billions	Dec. 31, 2018USD ($)
Short-term Debt [Line Items]
Deposits with the Federal Reserve	$ 2.1
Federal Reserve Bank of Cleveland [Member]
Short-term Debt [Line Items]
Unused Secured borrowing capacity	25.4
Federal Home Loan Bank of Cincinnati [Member]
Short-term Debt [Line Items]
Unused Secured borrowing capacity	$ 7.5

Long-Term Debt - Components of

Long-Term Debt - Components of Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total long-term debt	$ 13,732	$ 14,333
Real Estate Loans and securities pledged	1,100	1,100
Senior Medium-Term Notes Due Through 2021 [Member]
Debt Instrument [Line Items]
Senior medium-term notes	$ 3,278	$ 2,766
Long-term debt weighted average interest rate	4.057%	3.56%
3.136% Subordinated notes due 2028 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	3.136%
Subordinated long-term notes	$ 162	$ 161
6.875% Subordinated Notes Due 2029 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	6.875%
Subordinated long-term notes	$ 104	109
7.750% Subordinated Notes Due 2029 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	7.75%
Subordinated long-term notes	$ 135	141
7.25% Subordinated notes due 2021 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	7.25%
Subordinated long-term notes	$ 336	$ 348
Long-term debt weighted average interest rate	7.25%	7.25%
6.75% Senior Notes Due 2020 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	6.75%
Subordinated long-term notes	$ 315	$ 327
Long-term debt weighted average interest rate	6.75%	6.75%
Other Subordinated Notes [Member]
Debt Instrument [Line Items]
Subordinated long-term notes	$ 70	$ 69
Long-term debt weighted average interest rate	4.20%	3.022%
Senior Medium-Term Notes Due Through 2039 [Member]
Debt Instrument [Line Items]
Senior medium-term notes	$ 7,022	$ 8,011
Long-term debt weighted average interest rate	2.593%	2.24%
3.18% Senior Remarketable Notes Due 2027 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	3.18%
Subordinated long-term notes	$ 212	$ 202
Long-term debt weighted average interest rate	3.18%	3.18%
4.625% Subordinated notes due 2018 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	4.625%
Subordinated long-term notes	$ 0	$ 100
3.40% Subordinated notes due 2026 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	3.40%
Subordinated long-term notes	$ 560	565
6.95% Subordinated notes due 2028 [Member]
Debt Instrument [Line Items]
Debt instrument interest rate	6.95%
Subordinated long-term notes	$ 299	299
Secured Borrowing Due Through 2025 [Member]
Debt Instrument [Line Items]
Secured borrowing due through 2025	$ 10	$ 24
Long-term debt weighted average interest rate	4.455%	4.46%
Federal Home Loan Bank Advances Due Through 2038 [Member]
Debt Instrument [Line Items]
Federal Home Loan Bank advances due through 2038	$ 1,130	$ 1,106
Long-term debt weighted average interest rate	2.333%	2.318%
Investment Fund Financing Due Through 2052 [Member]
Debt Instrument [Line Items]
Investment Fund Financing due through 2052	$ 83	$ 88
Long-term debt weighted average interest rate	1.85%	1.94%
Obligations Under Capital Lease Due Through 2032 [Member]
Debt Instrument [Line Items]
Obligations under Capital Leases due 2032	$ 16	$ 17
Key [Member]
Debt Instrument [Line Items]
Total long-term debt	4,400	3,921
Subsidiaries [Member]
Debt Instrument [Line Items]
Total long-term debt	$ 9,332	$ 10,412

Long-Term Debt - Scheduled Prin

Long-Term Debt - Scheduled Principal Payments on Long-Term Debt (Details) $ in Millions	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
2,019	$ 2,262
2,020	2,694
2,021	3,094
2,022	1,469
2,023	456
All subsequent years	3,757
Key [Member]
Debt Instrument [Line Items]
2,019	0
2,020	1,298
2,021	1,350
2,022	0
2,023	0
All subsequent years	1,752
Subsidiaries [Member]
Debt Instrument [Line Items]
2,019	2,262
2,020	1,396
2,021	1,744
2,022	1,469
2,023	456
All subsequent years	$ 2,005

Long-Term Debt - Narrative (Det

Long-Term Debt - Narrative (Details)	Sep. 28, 2018USD ($)	Sep. 29, 2015USD ($)	Dec. 31, 2018USD ($)note	Oct. 29, 2018USD ($)	Jun. 13, 2018USD ($)	Apr. 30, 2018USD ($)	Mar. 07, 2018USD ($)	Sep. 14, 2017USD ($)	Jun. 09, 2017USD ($)
Debt Instrument [Line Items]
Bank note, maximum issuable amount	$ 20,000,000,000	$ 20,000,000,000
Senior notes available for future issuance			$ 20,000,000,000
Number of notes issued | note			0
Senior Notes [Member]
Debt Instrument [Line Items]
Original maturity of bank note	7 days	7 days
Subordinated Notes [Member]
Debt Instrument [Line Items]
Original maturity of bank note	5 years	5 years
2.40% Senior Bank Notes Due 2022 [Member]
Debt Instrument [Line Items]
Issuance of senior notes									$ 600,000,000
Debt instrument interest rate									2.40%
2.30% Senior Bank Notes Due 2022 [Member]
Debt Instrument [Line Items]
Issuance of senior notes								$ 750,000,000
Debt instrument interest rate								2.30%
3.375% Senior Notes Due 2023 [Member]
Debt Instrument [Line Items]
Issuance of senior notes							$ 500,000,000
Debt instrument interest rate							3.375%
3.35% Senior Notes Due 2021 [Member]
Debt Instrument [Line Items]
Issuance of senior notes					$ 500,000,000
Debt instrument interest rate					3.35%
Medium-Term Notes [Member]
Debt Instrument [Line Items]
Debt term			9 months
Additional debt securities authorized and available for issuance under note program			$ 2,750,000,000
4.10% Senior Notes Due 2028 [Member]
Debt Instrument [Line Items]
Issuance of senior notes						$ 750,000,000
Debt instrument interest rate						4.10%
4.150% Senior Notes Due 2025 [Member]
Debt Instrument [Line Items]
Issuance of senior notes				$ 500,000,000
Debt instrument interest rate				4.15%

Trust Preferred Securities Is_3

Trust Preferred Securities Issued by Unconsolidated Subsidiaries - Summary of Trust Preferred Securities, Common Stock and Related Debentures (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Stock	$ 1,257	$ 1,257
Debentures adjustments related to financial instrument hedging	46	55
KeyCorp Capital I [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	156
Common Stock	6
Principal Amount of of Debentures, Net of Discount	$ 162
Interest Rate of Trust Preferred Securities and Debentures	3.136%
KeyCorp Capital II [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 100
Common Stock	4
Principal Amount of of Debentures, Net of Discount	$ 104
Interest Rate of Trust Preferred Securities and Debentures	6.875%
KeyCorp Capital III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 131
Common Stock	4
Principal Amount of of Debentures, Net of Discount	$ 135
Interest Rate of Trust Preferred Securities and Debentures	7.75%
HNC Statutory Trust III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 19
Common Stock	1
Principal Amount of of Debentures, Net of Discount	$ 20
Interest Rate of Trust Preferred Securities and Debentures	4.053%
Willow Grove Statutory Trust I [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 18
Common Stock	1
Principal Amount of of Debentures, Net of Discount	$ 19
Interest Rate of Trust Preferred Securities and Debentures	4.098%
HNC Statutory Trust IV [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 16
Common Stock	1
Principal Amount of of Debentures, Net of Discount	$ 17
Interest Rate of Trust Preferred Securities and Debentures	3.80%
Westbank Capital Trust II [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 7
Common Stock	0
Principal Amount of of Debentures, Net of Discount	$ 7
Interest Rate of Trust Preferred Securities and Debentures	4.982%
Westbank Capital Trust III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 7
Common Stock	0
Principal Amount of of Debentures, Net of Discount	$ 7
Interest Rate of Trust Preferred Securities and Debentures	4.982%
Business Trusts [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Trust Preferred Securities, Net of Discount	$ 454	463
Common Stock	17	17
Principal Amount of of Debentures, Net of Discount	$ 471	$ 480
Interest Rate of Trust Preferred Securities and Debentures	5.447%	4.977%
Treasury Rate [Member] | KeyCorp Capital II [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	0.20%
Treasury Rate [Member] | KeyCorp Capital III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	0.25%
London Interbank Offered Rate (LIBOR) [Member] | KeyCorp Capital I [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	0.74%
London Interbank Offered Rate (LIBOR) [Member] | HNC Statutory Trust III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	1.40%
London Interbank Offered Rate (LIBOR) [Member] | Willow Grove Statutory Trust I [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	1.31%
London Interbank Offered Rate (LIBOR) [Member] | HNC Statutory Trust IV [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	1.28%
London Interbank Offered Rate (LIBOR) [Member] | Westbank Capital Trust II and III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	2.19%
Debt Instrument, Redemption, Period Five [Member] | Treasury Rate [Member] | Keycorp Capital II and III [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Basis spread on variable rate	0.50%

Commitments, Contingent Liabi_3

Commitments, Contingent Liabilities and Guarantees - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments Contingencies And Guarantees [Line Items]
Rental expense under all operating leases	$ 149	$ 153	$ 118
Minimum future rental payments under noncancelable operating leases due in 2019	142
Minimum future rental payments under noncancelable operating leases due in 2020	133
Minimum future rental payments under noncancelable operating leases due in 2021	118
Minimum future rental payments under noncancelable operating leases due in 2022	104
Minimum future rental payments under noncancelable operating leases due in 2023	90
Minimum future rental payments under noncancelable operating leases, all subsequent years	321
Default guarantees, value	174
Written Put Options [Member]
Commitments Contingencies And Guarantees [Line Items]
Default guarantees, value	$ 88
Weighted average life of written put options	3 years
Standby Letters of Credit [Member]
Commitments Contingencies And Guarantees [Line Items]
Remaining weighted-average life of standby letters of credit in years	2 years
Default guarantees, value	$ 72
Underwriting And Servicing Program [Member]
Commitments Contingencies And Guarantees [Line Items]
Weighted-average remaining term for outstanding commercial mortgage loans in years	7 years 10 months 24 days
Unpaid principal balance outstanding of loans sold	$ 14,100
Maximum potential amount of undiscounted future payments that could be required, percentage of principal balance of loans outstanding	29.00%
Default guarantees, value	$ 6
Residential Mortgage Reserve [Member]
Commitments Contingencies And Guarantees [Line Items]
Unpaid principal balance outstanding of loans sold	$ 5,200
Maximum potential amount of undiscounted future payments that could be required, percentage of principal balance of loans outstanding	30.00%
Weighted average loan to value ratio (as a percentage)	74.00%
Liability for estimated repurchase obligations on loans sold	$ 6
Return Guarantee Agreement with LIHTC Investors [Member]
Commitments Contingencies And Guarantees [Line Items]
Default guarantees, value	$ 2
Compliance period of property	15 years
Default Guarantees [Member]
Commitments Contingencies And Guarantees [Line Items]
Default guarantees, value	$ 1
Minimum [Member] | Standby Letters of Credit [Member]
Commitments Contingencies And Guarantees [Line Items]
Remaining actual life letters of credit in years	1 year
Minimum [Member] | Low [Member]
Commitments Contingencies And Guarantees [Line Items]
Guarantee obligations, probability of payment (percentage)	0.00%
Minimum [Member] | Moderate [Member]
Commitments Contingencies And Guarantees [Line Items]
Guarantee obligations, probability of payment (percentage)	30.00%
Minimum [Member] | High [Member]
Commitments Contingencies And Guarantees [Line Items]
Guarantee obligations, probability of payment (percentage)	70.00%
Maximum [Member] | Standby Letters of Credit [Member]
Commitments Contingencies And Guarantees [Line Items]
Remaining actual life letters of credit in years	16 years
Maximum [Member] | Low [Member]
Commitments Contingencies And Guarantees [Line Items]
Guarantee obligations, probability of payment (percentage)	30.00%
Maximum [Member] | Moderate [Member]
Commitments Contingencies And Guarantees [Line Items]
Guarantee obligations, probability of payment (percentage)	70.00%

Commitments, Contingent Liabi_4

Commitments, Contingent Liabilities and Guarantees - Commitments to Extend Credit or Funding (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Guarantor Obligations [Line Items]
Total loan commitments	$ 61,478	$ 58,652
Commercial letters of credit	86	231
Purchase card commitments	621	425
Principal investing commitments	26	29
Tax credit investment commitments	520	481
Securities underwriting	0	9
Total loan and other commitments	62,731	59,827
Commercial and Other [Member]
Guarantor Obligations [Line Items]
Total loan commitments	42,653	40,315
Commercial Real Estate and Construction [Member]
Guarantor Obligations [Line Items]
Total loan commitments	2,691	2,774
Home Equity [Member]
Guarantor Obligations [Line Items]
Total loan commitments	9,982	9,673
Credit Cards [Member]
Guarantor Obligations [Line Items]
Total loan commitments	$ 6,152	$ 5,890

Commitments, Contingent Liabi_5

Commitments, Contingent Liabilities and Guarantees - Guarantees (Details) $ in Millions	Dec. 31, 2018USD ($)
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	$ 11,115
Liability Recorded	174
Written Put Options [Member]
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	2,345
Liability Recorded	88
Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	3,137
Liability Recorded	72
Recourse Agreement with FNMA [Member]
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	4,082
Liability Recorded	6
Residential Mortgage Reserve [Member]
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	1,549
Return Guarantee Agreement with LIHTC Investors [Member]
Guarantor Obligations [Line Items]
Maximum Potential Undiscounted Future Payments	2
Liability Recorded	$ 2

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income - Changes in AOCI (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		$ 15,025
Other comprehensive income before reclassification, net of income taxes		(80)	$ (96)
Amounts reclassified from accumulated other comprehensive income, net of income taxes		54	(1)
Amounts reclassified from accumulated other comprehensive income resulting from new federal corporate income tax rate	$ 141		(141)
Other amounts reclassified from AOCI, net of income taxes		(13)
Total other comprehensive income (loss), net of tax		(39)	(238)	$ (136)
Ending Balance	15,025	15,596	15,025
Unrealized Gains (Losses) on Securities Available for Sale [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(311)	(185)
Other comprehensive income before reclassification, net of income taxes		(62)	(69)
Amounts reclassified from accumulated other comprehensive income, net of income taxes		0	(1)
Amounts reclassified from accumulated other comprehensive income resulting from new federal corporate income tax rate			(56)
Other amounts reclassified from AOCI, net of income taxes		0
Total other comprehensive income (loss), net of tax		(62)	(126)
Ending Balance	(311)	(373)	(311)	(185)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(86)	(14)
Other comprehensive income before reclassification, net of income taxes		7	(48)
Amounts reclassified from accumulated other comprehensive income, net of income taxes		29	(10)
Amounts reclassified from accumulated other comprehensive income resulting from new federal corporate income tax rate			(14)
Other amounts reclassified from AOCI, net of income taxes		0
Total other comprehensive income (loss), net of tax		36	(72)
Ending Balance	(86)	(50)	(86)	(14)
Foreign Currency Translation Adjustment [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		9	(3)
Other comprehensive income before reclassification, net of income taxes		(10)	12
Amounts reclassified from accumulated other comprehensive income, net of income taxes		0	1
Amounts reclassified from accumulated other comprehensive income resulting from new federal corporate income tax rate			(1)
Other amounts reclassified from AOCI, net of income taxes		(13)
Total other comprehensive income (loss), net of tax		(23)	12
Ending Balance	9	(14)	9	(3)
Net Pension and Postretirement Benefit Costs [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(391)	(339)
Other comprehensive income before reclassification, net of income taxes		(15)	9
Amounts reclassified from accumulated other comprehensive income, net of income taxes		25	9
Amounts reclassified from accumulated other comprehensive income resulting from new federal corporate income tax rate			(70)
Other amounts reclassified from AOCI, net of income taxes		0
Total other comprehensive income (loss), net of tax		10	(52)
Ending Balance	(391)	(381)	(391)	(339)
AOCI Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(779)	(541)	(405)
Total other comprehensive income (loss), net of tax		(39)	(238)	(136)
Ending Balance	$ (779)	$ (818)	$ (779)	$ (541)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income - Reclassifications Out of AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Realized gains	$ 0	$ 1	$ 0
Realized losses	0	0	0
Interest income — Loans	4,023	3,677	2,773
Interest expense — Long-term debt	(420)	(319)	(218)
Investment banking and debt placement fees	650	603	482
Personnel expense	(2,309)	(2,278)	(2,048)
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries	2,234	1,981	1,002
Income taxes	344	637	179
Income (loss) from continuing operations	1,859	1,291	$ 789
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Securities Available for Sale [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries	0	1
Income taxes	0	0
Income (loss) from continuing operations	0	1
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries	(37)	15
Income taxes	(8)	5
Income (loss) from continuing operations	(29)	10
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Currency Translation Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Personnel expense	0	(1)
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries	0	(1)
Income taxes	0	0
Income (loss) from continuing operations	0	(1)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Pension and Postretirement Benefit Costs [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries	(33)	(14)
Income taxes	(8)	(5)
Income (loss) from continuing operations	(25)	(9)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Pension and Postretirement Benefit Costs [Member] | Amortization of Losses [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Personnel expense	(17)	(15)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Pension and Postretirement Benefit Costs [Member] | Settlement Loss [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Personnel expense	17	0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Pension and Postretirement Benefit Costs [Member] | Amortization Of Prior Service Credit [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Personnel expense	1	1
Other Income [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains (Losses) on Securities Available for Sale [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Realized gains	0	1
Realized losses	0	0
Other Income [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] | Foreign Exchange Contract [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Unrealized gain (loss) on derivatives	31	0
Interest Income [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] | Interest Rate [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income — Loans	(68)	19
Interest Expense [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] | Interest Rate [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense — Long-term debt	2	4
Investment Banking And Debt Placement [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] | Interest Rate [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment banking and debt placement fees	$ 2	$ 0

Shareholders' Equity - Comprehe

Shareholders' Equity - Comprehensive Capital Plan (Details) - USD ($)	3 Months Ended				12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash dividends declared per common share (in dollars per share)	$ 0.17	$ 0.17	$ 0.12	$ 0.105	$ 0.565	$ 0.38	$ 0.33
2018 Capital Plan [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Authorized amount of share repurchases	$ 1,225,000,000				$ 1,225,000,000
Common shares repurchased, value					820,000,000
2017 Capital Plan [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common shares repurchased, value					$ 325,000,000

Shareholders' Equity - Schedule

Shareholders' Equity - Schedule of Preferred Stock (Details)	Dec. 31, 2018USD ($)$ / sharesshares
Series D Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, amount outstanding | $	$ 525,000,000
Preferred stock, shares authorized (in shares) | shares	21,000
Preferred stock, shares outstanding (in shares) | shares	21,000
Preferred stock, par value (in usd per share)	$ 1
Preferred stock, liquidation preference, value | $	$ 25,000
Depository Shares, Series D [Member]
Class of Stock [Line Items]
Depository receipt ratio	0.04
Preferred stock, liquidation preference (in usd per share)	$ 1,000
Dividend payable per share (in usd per share)	$ 50
Series E Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, amount outstanding | $	$ 500,000,000
Preferred stock, shares authorized (in shares) | shares	500,000
Preferred stock, shares outstanding (in shares) | shares	500,000
Preferred stock, par value (in usd per share)	$ 1
Preferred stock, liquidation preference, value | $	$ 1,000
Depository Shares, Series E [Member]
Class of Stock [Line Items]
Depository receipt ratio	25,000
Preferred stock, liquidation preference (in usd per share)	$ 25
Dividend payable per share (in usd per share)	$ 1.531252
Series F Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, amount outstanding | $	$ 425,000,000
Preferred stock, shares authorized (in shares) | shares	425,000
Preferred stock, shares outstanding (in shares) | shares	425,000
Preferred stock, par value (in usd per share)	$ 1
Preferred stock, liquidation preference, value | $	$ 1,000
Depository Shares, Series F [Member]
Class of Stock [Line Items]
Depository receipt ratio	25,000
Preferred stock, liquidation preference (in usd per share)	$ 25
Dividend payable per share (in usd per share)	$ 0.529688

Shareholders' Equity - Key's an

Shareholders' Equity - Key's and KeyBank's Actual Capital Amounts and Ratios, Minimum Capital Amounts and Ratios (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Key [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital to Net Risk-Weighted Assets, Actual Amount	$ 15,953	$ 15,345
Tier 1 Capital to Average Quarterly Tangible Assets, Amount	13,712	13,083
Tier 1 Capital to Net Risk-Weighted Assets, Actual Amount	$ 13,712	$ 13,083
Total Capital to Net Risk-Weighted Assets, Actual Ratio	12.89%	12.92%
Tier 1 Capital to Net Risk-Weighted Assets, Actual Ratio	11.08%	11.01%
Tier 1 Capital to Average Quarterly Tangible Assets, Actual Ratio	9.89%	9.73%
Total Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Amount	$ 9,903	$ 9,505
Tier 1 Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Amount	7,427	7,129
Tier 1 Capital to Average Quarterly Tangible Assets to Meet Minimum Capital Adequacy Requirements, Amount	$ 5,548	$ 5,379
Total Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Ratio	8.00%	8.00%
Tier 1 Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Ratio	6.00%	6.00%
Tier 1 Capital to Average Quarterly Tangible Assets to Meet Minimum Capital Adequacy Requirements, Ratio	4.00%	4.00%
KeyBank (consolidated) [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital to Net Risk-Weighted Assets, Actual Amount	$ 15,432	$ 14,957
Tier 1 Capital to Average Quarterly Tangible Assets, Amount	13,575	13,110
Tier 1 Capital to Net Risk-Weighted Assets, Actual Amount	$ 13,575	$ 13,110
Total Capital to Net Risk-Weighted Assets, Actual Ratio	12.68%	12.86%
Tier 1 Capital to Net Risk-Weighted Assets, Actual Ratio	11.16%	11.27%
Tier 1 Capital to Average Quarterly Tangible Assets, Actual Ratio	9.93%	9.91%
Total Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Amount	$ 9,733	$ 9,306
Tier 1 Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Amount	7,300	6,980
Tier 1 Capital to Average Quarterly Tangible Assets to Meet Minimum Capital Adequacy Requirements, Amount	$ 5,470	$ 5,293
Total Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Ratio	8.00%	8.00%
Tier 1 Capital to Net Risk-Weighted Assets, to Meet Minimum Capital Adequacy Requirements, Ratio	6.00%	6.00%
Tier 1 Capital to Average Quarterly Tangible Assets to Meet Minimum Capital Adequacy Requirements, Ratio	4.00%	4.00%
Total Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Amount	$ 12,166	$ 11,633
Tier 1 Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Amount	7,300	6,980
Tier 1 Capital to Average Quarterly Tangible Assets to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Amount	$ 6,838	$ 6,617
Total Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio	10.00%	10.00%
Tier 1 Capital to Net Risk-Weighted Assets, to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio	6.00%	6.00%
Tier 1 Capital to Average Quarterly Tangible Assets to Qualify as Well Capitalized Under Federal Deposit Insurance Act, Ratio	5.00%	5.00%

Line of Business Results - Narr

Line of Business Results - Narrative (Details)	12 Months Ended
	Dec. 31, 2018Branchindustry_sector	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting [Abstract]
Number of state branch network | Branch	15
Number of business units | industry_sector	7
Federal income tax rate	21.00%	35.00%	35.00%
State income tax rate	2.70%	2.20%

Line of Business Results - Fina

Line of Business Results - Financial Information of Business Groups (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)employee	Dec. 31, 2017USD ($)employee	Dec. 31, 2016USD ($)employee
Segment Reporting Information [Line Items]
Net interest income (TE)	$ 3,940	$ 3,830	$ 2,953
Noninterest income	2,515	2,478	2,071
Total revenue (TE)	6,455	6,308	5,024
Provision for credit losses	246	229	266
Depreciation and amortization expense	400	384	303
Other noninterest expense	3,575	3,714	3,453
Income (loss) from continuing operations before income taxes (TE)	2,234	1,981	1,002
Allocated income taxes (benefit) and TE adjustments	375	690	213
INCOME (LOSS) FROM CONTINUING OPERATIONS	1,859	1,291	789
Income (loss) from discontinued operations, net of taxes	7	7	1
NET INCOME (LOSS)	1,866	1,298	790
Less: Net income (loss) attributable to noncontrolling interests	0	2	(1)
NET INCOME (LOSS) ATTRIBUTABLE TO KEY	1,866	1,296	791
AVERAGE BALANCES
Loans and leases	88,338	86,365	71,148
Total assets	136,812	133,719	112,537
Deposits	105,051	102,946	86,352
OTHER FINANCIAL DATA
Expenditures for additions to long-lived assets	3,001	3,097	1,934
Net loan charge-offs	$ 234	$ 208	$ 205
Return on average allocated equity, continuing operations (as a percentage)	12.29%	8.47%	6.25%
Return on average allocated equity (as a percentage)	12.33%	8.51%	6.25%
Average full-time equivalent employees | employee	18,180	18,415	15,700
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net interest income (TE)	$ 3,912	$ 3,810	$ 2,957
Noninterest income	2,465	2,499	2,089
Total revenue (TE)	6,377	6,309	5,046
Provision for credit losses	246	229	266
Depreciation and amortization expense	246	215	140
Other noninterest expense	3,651	3,683	3,182
Income (loss) from continuing operations before income taxes (TE)	2,234	2,182	1,458
Allocated income taxes (benefit) and TE adjustments	393	589	376
INCOME (LOSS) FROM CONTINUING OPERATIONS	1,841	1,593	1,082
Income (loss) from discontinued operations, net of taxes	0	0	0
NET INCOME (LOSS)	1,841	1,593	1,082
Less: Net income (loss) attributable to noncontrolling interests	0	3	0
NET INCOME (LOSS) ATTRIBUTABLE TO KEY	1,841	1,590	1,082
AVERAGE BALANCES
Loans and leases	88,329	86,340	71,035
Total assets	136,451	133,033	110,035
Deposits	105,007	102,975	85,868
OTHER FINANCIAL DATA
Expenditures for additions to long-lived assets	2,900	3,016	1,818
Net loan charge-offs	$ 233	$ 207	$ 204
Return on average allocated equity, continuing operations (as a percentage)	23.37%	20.41%	18.36%
Return on average allocated equity (as a percentage)	23.37%	20.41%	18.36%
Average full-time equivalent employees | employee	13,159	13,332	11,185
Operating Segments [Member] | Key Community Bank [Member]
Segment Reporting Information [Line Items]
Net interest income (TE)	$ 2,873	$ 2,652	$ 1,953
Noninterest income	1,098	1,143	906
Total revenue (TE)	3,971	3,795	2,859
Provision for credit losses	177	209	143
Depreciation and amortization expense	110	116	76
Other noninterest expense	2,451	2,424	2,048
Income (loss) from continuing operations before income taxes (TE)	1,233	1,046	592
Allocated income taxes (benefit) and TE adjustments	291	388	220
INCOME (LOSS) FROM CONTINUING OPERATIONS	942	658	372
Income (loss) from discontinued operations, net of taxes	0	0	0
NET INCOME (LOSS)	942	658	372
Less: Net income (loss) attributable to noncontrolling interests	0	0	0
NET INCOME (LOSS) ATTRIBUTABLE TO KEY	942	658	372
AVERAGE BALANCES
Loans and leases	47,877	47,399	37,624
Total assets	51,774	51,370	40,300
Deposits	81,868	79,669	63,875
OTHER FINANCIAL DATA
Expenditures for additions to long-lived assets	2,352	2,438	1,478
Net loan charge-offs	$ 161	$ 166	$ 114
Return on average allocated equity, continuing operations (as a percentage)	19.50%	13.71%	10.96%
Return on average allocated equity (as a percentage)	19.50%	13.71%	10.96%
Average full-time equivalent employees | employee	10,501	10,587	8,794
Operating Segments [Member] | Key Corporate Bank [Member]
Segment Reporting Information [Line Items]
Net interest income (TE)	$ 1,094	$ 1,193	$ 1,049
Noninterest income	1,161	1,148	1,013
Total revenue (TE)	2,255	2,341	2,062
Provision for credit losses	74	20	127
Depreciation and amortization expense	135	96	60
Other noninterest expense	1,147	1,158	1,073
Income (loss) from continuing operations before income taxes (TE)	899	1,067	802
Allocated income taxes (benefit) and TE adjustments	110	249	178
INCOME (LOSS) FROM CONTINUING OPERATIONS	789	818	624
Income (loss) from discontinued operations, net of taxes	0	0	0
NET INCOME (LOSS)	789	818	624
Less: Net income (loss) attributable to noncontrolling interests	0	0	(2)
NET INCOME (LOSS) ATTRIBUTABLE TO KEY	789	818	626
AVERAGE BALANCES
Loans and leases	39,536	37,716	31,925
Total assets	47,126	44,505	37,797
Deposits	21,183	21,318	20,780
OTHER FINANCIAL DATA
Expenditures for additions to long-lived assets	538	559	340
Net loan charge-offs	$ 73	$ 40	$ 83
Return on average allocated equity, continuing operations (as a percentage)	27.01%	28.82%	26.89%
Return on average allocated equity (as a percentage)	27.01%	28.82%	26.89%
Average full-time equivalent employees | employee	2,528	2,407	2,244
Operating Segments [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Net interest income (TE)	$ (55)	$ (35)	$ (45)
Noninterest income	206	208	170
Total revenue (TE)	151	173	125
Provision for credit losses	(5)	0	(4)
Depreciation and amortization expense	1	3	4
Other noninterest expense	53	101	61
Income (loss) from continuing operations before income taxes (TE)	102	69	64
Allocated income taxes (benefit) and TE adjustments	(8)	(48)	(22)
INCOME (LOSS) FROM CONTINUING OPERATIONS	110	117	86
Income (loss) from discontinued operations, net of taxes	0	0	0
NET INCOME (LOSS)	110	117	86
Less: Net income (loss) attributable to noncontrolling interests	0	3	2
NET INCOME (LOSS) ATTRIBUTABLE TO KEY	110	114	84
AVERAGE BALANCES
Loans and leases	916	1,225	1,486
Total assets	37,551	37,158	31,938
Deposits	1,956	1,988	1,213
OTHER FINANCIAL DATA
Expenditures for additions to long-lived assets	10	19	0
Net loan charge-offs	$ (1)	$ 1	$ 7
Return on average allocated equity, continuing operations (as a percentage)	88.00%	73.55%	48.84%
Return on average allocated equity (as a percentage)	88.00%	73.55%	48.84%
Average full-time equivalent employees | employee	130	338	147
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Net interest income (TE)	$ 28	$ 20	$ (4)
Noninterest income	50	(21)	(18)
Total revenue (TE)	78	(1)	(22)
Provision for credit losses	0	0	0
Depreciation and amortization expense	154	169	163
Other noninterest expense	(76)	31	271
Income (loss) from continuing operations before income taxes (TE)	0	(201)	(456)
Allocated income taxes (benefit) and TE adjustments	(18)	101	(163)
INCOME (LOSS) FROM CONTINUING OPERATIONS	18	(302)	(293)
Income (loss) from discontinued operations, net of taxes	7	7	1
NET INCOME (LOSS)	25	(295)	(292)
Less: Net income (loss) attributable to noncontrolling interests	0	(1)	(1)
NET INCOME (LOSS) ATTRIBUTABLE TO KEY	25	(294)	(291)
AVERAGE BALANCES
Loans and leases	9	25	113
Total assets	361	686	2,502
Deposits	44	(29)	484
OTHER FINANCIAL DATA
Expenditures for additions to long-lived assets	101	81	116
Net loan charge-offs	$ 1	$ 1	$ 1
Return on average allocated equity, continuing operations (as a percentage)	0.25%	(4.05%)	(4.32%)
Return on average allocated equity (as a percentage)	0.34%	(3.96%)	(4.31%)
Average full-time equivalent employees | employee	5,021	5,083	4,515

Condensed Financial Informati_3

Condensed Financial Information of the Parent Company - Condensed Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Cash and due from banks	$ 678	$ 671	$ 677	$ 607
Short-term investments	2,562	4,447
Securities available for sale	19,428	18,139
Other investments	666	726
Total loans	88,669	85,528
Goodwill	2,516	2,538	2,446
Corporate-owned life insurance	4,171	4,132
Derivative assets	531	669
Accrued income and other assets	4,037	4,237
Total assets	139,613	137,698
Accrued expense and other liabilities	2,113	2,094
Total long-term debt	13,732	14,333
Total liabilities	124,017	122,673
SHAREHOLDERS' EQUITY	15,595	15,023
Total liabilities and equity	139,613	137,698
Key [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and due from banks	3,241	2,257	$ 3,286	$ 2,608
Short-term investments	19	22
Securities available for sale	10	10
Other investments	31	29
Total loans	81	281
Total investment in subsidiaries	16,387	16,054
Goodwill	167	167
Corporate-owned life insurance	199	208
Derivative assets	61	29
Accrued income and other assets	279	353
Total assets	20,475	19,410
Accrued expense and other liabilities	480	466
Long term debt due to Subsidiaries	471	480
Total long-term debt	4,400	3,921
Total liabilities	4,880	4,387
SHAREHOLDERS' EQUITY	15,595	15,023
Total liabilities and equity	20,475	19,410
Key [Member] | Banks [Member]
Condensed Financial Statements, Captions [Line Items]
Total loans	50	250
Investment in subsidiaries	15,554	15,169
Key [Member] | Nonbank Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Total loans	31	31
Investment in subsidiaries	833	885
Key [Member] | Unaffiliated Companies [Member]
Condensed Financial Statements, Captions [Line Items]
Total long-term debt	$ 3,929	$ 3,441

Condensed Financial Informati_4

Condensed Financial Information of the Parent Company - Condensed Statements of Income (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Other income	[1]	$ 176	$ 153	$ 114
Total interest income		4,878	4,390	3,319
Interest on long-term debt with subsidiary trusts		420	319	218
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries		2,234	1,981	1,002
Income tax (expense) benefit		(344)	(637)	(179)
NET INCOME (LOSS)		1,866	1,298	790
Less: Net income attributable to noncontrolling interests		0	2	(1)
NET INCOME (LOSS) ATTRIBUTABLE TO KEY		1,866	1,296	791
Key [Member]
Condensed Financial Statements, Captions [Line Items]
Interest income from subsidiaries		11	10	10
Other income		11	9	11
Total interest income		1,697	769	696
Interest on long-term debt with subsidiary trusts		20	17	14
Interest on other borrowed funds		137	95	69
Personnel and other expense		69	46	101
Total expense		226	158	184
Income (loss) before income taxes and equity in net income (loss) less dividends from subsidiaries		1,471	611	512
Income tax (expense) benefit		55	29	54
Income (loss) before equity in net income (loss) less dividends from subsidiaries		1,526	640	566
Equity in net income (loss) less dividends from subsidiaries		340	658	224
NET INCOME (LOSS)		1,866	1,298	790
Less: Net income attributable to noncontrolling interests		0	2	(1)
NET INCOME (LOSS) ATTRIBUTABLE TO KEY		1,866	1,296	791
Key [Member] | Banks [Member]
Condensed Financial Statements, Captions [Line Items]
Bank/Nonbank subsidiaries		1,675	750	625
Key [Member] | Nonbank Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Bank/Nonbank subsidiaries		$ 0	$ 0	$ 50
[1]	Net securities gains (losses) totaled less than $1 million for each of the years ended December 31, 2018 , 2017 , and 2016 . For 2018 , 2017 , and 2016

Condensed Financial Informati_5

Condensed Financial Information of the Parent Company - Condensed Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
OPERATING ACTIVITIES
Net income (loss) attributable to Key	$ 1,866	$ 1,296	$ 791
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Deferred income taxes (benefit)	98	303	11
Stock-based compensation expense	99	100	99
Other operating activities, net	14	(601)	175
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	2,506	1,815	1,689
INVESTING ACTIVITIES
Net decrease (increase) in short-term investments, excluding acquisitions	1,885	(1,672)	(68)
Cash used in acquisitions	0	(144)	(481)
Proceeds from sales, prepayments and maturities of securities available for sale	3,197	3,999	4,241
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	(2,482)	(2,239)	(6,457)
FINANCING ACTIVITIES
Net proceeds from issuance of long-term debt	2,306	2,852	2,827
Payments on long-term debt	(2,880)	(748)	(1,308)
Repurchase of Treasury Shares	(1,098)	(664)	(140)
Cash dividends paid	(656)	(480)	(335)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(17)	418	4,838
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	7	(6)	70
CASH AND DUE FROM BANKS AT BEGINNING OF YEAR	671	677	607
CASH AND DUE FROM BANKS AT END OF YEAR	678	671	677
Key [Member]
OPERATING ACTIVITIES
Net income (loss) attributable to Key	1,866	1,296	791
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Deferred income taxes (benefit)	109	38	(24)
Stock-based compensation expense	8	11	12
Equity in net (income) loss less dividends from subsidiaries	(340)	(658)	(224)
Other intangible asset amortization	0	0	0
Net (increase) decrease in goodwill and other intangibles	0	0	0
Net (increase) decrease in other assets	(58)	82	(93)
Net increase (decrease) in other liabilities	8	(82)	9
Other operating activities, net	79	(114)	0
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	1,672	573	471
INVESTING ACTIVITIES
Net decrease (increase) in short-term investments, excluding acquisitions	1	47	(17)
Cash infusion from purchase of Cain Brothers	0	(90)	0
Cash used in acquisitions	0	0	(481)
Proceeds from sales, prepayments and maturities of securities available for sale	0	1	0
Net (increase) decrease in loans to subsidiaries	200	0	160
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	201	(42)	(338)
FINANCING ACTIVITIES
Net proceeds from issuance of long-term debt	1,250	0	0
Payments on long-term debt	(750)	0	(21)
Repurchase of Treasury Shares	(1,145)	(730)	(140)
Net cash from the issuance (redemption) of Common Shares and preferred stock	412	(350)	1,041
Cash dividends paid	(656)	(480)	(335)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(889)	(1,560)	545
NET INCREASE (DECREASE) IN CASH AND DUE FROM BANKS	984	(1,029)	678
CASH AND DUE FROM BANKS AT BEGINNING OF YEAR	2,257	3,286	2,608
CASH AND DUE FROM BANKS AT END OF YEAR	$ 3,241	$ 2,257	$ 3,286

Condensed Financial Informati_6

Condensed Financial Information of the Parent Company - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Interest paid	$ 892	$ 598	$ 429
Key [Member]
Condensed Financial Statements, Captions [Line Items]
Interest paid	$ 131	$ 120	$ 114

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 1,330,000,000
Noninterest income	2,515,000,000	$ 2,478,000,000	$ 2,071,000,000
Contract assets	0
Contract liabilities	0
Trust And Investment Services [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	427,000,000
Investment Banking And Debt Placement [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	260,000,000
Service Charges On Deposit Accounts [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	362,000,000
Cards And Payments [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	263,000,000
Other Noninterest Income [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	18,000,000
Noninterest income	929,000,000
Operating Segments [Member]
Disaggregation of Revenue [Line Items]
Noninterest income	2,465,000,000	2,499,000,000	2,089,000,000
Operating Segments [Member] | Key Community Bank [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	846,000,000
Noninterest income	1,098,000,000	1,143,000,000	906,000,000
Operating Segments [Member] | Key Community Bank [Member] | Trust And Investment Services [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	358,000,000
Operating Segments [Member] | Key Community Bank [Member] | Investment Banking And Debt Placement [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5,000,000
Operating Segments [Member] | Key Community Bank [Member] | Service Charges On Deposit Accounts [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	310,000,000
Operating Segments [Member] | Key Community Bank [Member] | Cards And Payments [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	155,000,000
Operating Segments [Member] | Key Community Bank [Member] | Other Noninterest Income [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	18,000,000
Operating Segments [Member] | Key Corporate Bank [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	484,000,000
Noninterest income	1,161,000,000	1,148,000,000	1,013,000,000
Operating Segments [Member] | Key Corporate Bank [Member] | Trust And Investment Services [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	69,000,000
Operating Segments [Member] | Key Corporate Bank [Member] | Investment Banking And Debt Placement [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	255,000,000
Operating Segments [Member] | Key Corporate Bank [Member] | Service Charges On Deposit Accounts [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	52,000,000
Operating Segments [Member] | Key Corporate Bank [Member] | Cards And Payments [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	108,000,000
Operating Segments [Member] | Key Corporate Bank [Member] | Other Noninterest Income [Member]
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0
Operating Segments [Member] | Other Segments [Member]
Disaggregation of Revenue [Line Items]
Noninterest income	206,000,000	208,000,000	170,000,000
Segment Reconciling Items [Member]
Disaggregation of Revenue [Line Items]
Noninterest income	$ 50,000,000	$ (21,000,000)	$ (18,000,000)

Uncategorized Items - key-12311

Label	Element	Value
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (2,000,000)	[1]
[1]	Includes the impact of implementing ASU 2014-09, ASU 2016-01, and ASU 2017-12