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