Loans and Allowance for Loan Losses - Schedule of Loan Portfolio Class by Risk Grade and Origination Year (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2025
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	$ 18,394		$ 18,394		$ 11,306
Term loans amortized cost basis by origination, before current fiscal year	17,900		17,900		5,091
Term loans amortized cost basis by origination, two years before current fiscal year	7,548		7,548		3,480
Term loans amortized cost basis by origination, three years before current fiscal year	5,044		5,044		6,201
Term loans amortized cost basis by origination, four years before current fiscal year	8,294		8,294		3,256
Term loans amortized cost basis by origination, prior	12,278		12,278		2,163
Amortized Cost Basis	20,350		20,350		7,657
Total	89,808		89,808		39,154
Gross charge-offs
Year One			6		4
Year Two			33		8
Year Three			34		12
Year Four			17		15
Year Five			15		28
Prior			35		4
Amortized Cost Basis			45		25
Total	70	$ 22	185	$ 62	96
Total commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	10,398		10,398		6,939
Term loans amortized cost basis by origination, before current fiscal year	10,116		10,116		3,528
Term loans amortized cost basis by origination, two years before current fiscal year	4,305		4,305		1,996
Term loans amortized cost basis by origination, three years before current fiscal year	2,757		2,757		2,043
Term loans amortized cost basis by origination, four years before current fiscal year	2,965		2,965		1,207
Term loans amortized cost basis by origination, prior	5,291		5,291		963
Amortized Cost Basis	16,231		16,231		5,620
Total	52,063		52,063		22,296
Gross charge-offs
Year One			6		4
Year Two			20		8
Year Three			30		11
Year Four			12		15
Year Five			13		7
Prior			24		2
Amortized Cost Basis			34		19
Total			139		66
Total commercial and industrial \| Commercial, financial and agricultural
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	7,069		7,069		5,292
Term loans amortized cost basis by origination, before current fiscal year	6,482		6,482		2,757
Term loans amortized cost basis by origination, two years before current fiscal year	2,848		2,848		1,282
Term loans amortized cost basis by origination, three years before current fiscal year	1,490		1,490		951
Term loans amortized cost basis by origination, four years before current fiscal year	1,148		1,148		467
Term loans amortized cost basis by origination, prior	2,959		2,959		340
Amortized Cost Basis	15,460		15,460		5,460
Total	37,456		37,456		16,549
Gross charge-offs
Year One			6		4
Year Two			20		7
Year Three			30		11
Year Four			12		15
Year Five			8		7
Prior			7		2
Amortized Cost Basis			34		19
Total			117		65
Total commercial and industrial \| Commercial, financial and agricultural \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	6,977		6,977		5,207
Term loans amortized cost basis by origination, before current fiscal year	6,404		6,404		2,722
Term loans amortized cost basis by origination, two years before current fiscal year	2,721		2,721		1,219
Term loans amortized cost basis by origination, three years before current fiscal year	1,363		1,363		901
Term loans amortized cost basis by origination, four years before current fiscal year	1,068		1,068		450
Term loans amortized cost basis by origination, prior	2,927		2,927		334
Amortized Cost Basis	15,072		15,072		5,323
Total	36,532		36,532		16,156
Total commercial and industrial \| Commercial, financial and agricultural \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	15		15		54
Term loans amortized cost basis by origination, before current fiscal year	30		30		29
Term loans amortized cost basis by origination, two years before current fiscal year	62		62		51
Term loans amortized cost basis by origination, three years before current fiscal year	66		66		39
Term loans amortized cost basis by origination, four years before current fiscal year	39		39		14
Term loans amortized cost basis by origination, prior	11		11		2
Amortized Cost Basis	171		171		118
Total	394		394		307
Total commercial and industrial \| Commercial, financial and agricultural \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	77		77		31
Term loans amortized cost basis by origination, before current fiscal year	48		48		6
Term loans amortized cost basis by origination, two years before current fiscal year	65		65		12
Term loans amortized cost basis by origination, three years before current fiscal year	61		61		11
Term loans amortized cost basis by origination, four years before current fiscal year	36		36		3
Term loans amortized cost basis by origination, prior	18		18		4
Amortized Cost Basis	216		216		19
Total	521		521		86
Total commercial and industrial \| Commercial, financial and agricultural \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0
Term loans amortized cost basis by origination, before current fiscal year	0		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0
Term loans amortized cost basis by origination, three years before current fiscal year	0		0
Term loans amortized cost basis by origination, four years before current fiscal year	5		5
Term loans amortized cost basis by origination, prior	3		3
Amortized Cost Basis	0		0
Total	8		8
Total commercial and industrial \| Commercial, financial and agricultural \| Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0
Term loans amortized cost basis by origination, before current fiscal year	0		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0
Term loans amortized cost basis by origination, three years before current fiscal year	0		0
Term loans amortized cost basis by origination, four years before current fiscal year	0		0
Term loans amortized cost basis by origination, prior	0		0
Amortized Cost Basis	1		1
Total	1		1
Total commercial and industrial \| Owner-occupied
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	3,329		3,329		1,647
Term loans amortized cost basis by origination, before current fiscal year	3,634		3,634		771
Term loans amortized cost basis by origination, two years before current fiscal year	1,457		1,457		714
Term loans amortized cost basis by origination, three years before current fiscal year	1,267		1,267		1,092
Term loans amortized cost basis by origination, four years before current fiscal year	1,817		1,817		740
Term loans amortized cost basis by origination, prior	2,332		2,332		623
Amortized Cost Basis	771		771		160
Total	14,607		14,607		5,747
Gross charge-offs
Year One			0		0
Year Two			0		1
Year Three			0		0
Year Four			0		0
Year Five			5		0
Prior			17		0
Amortized Cost Basis			0		0
Total			22		1
Total commercial and industrial \| Owner-occupied \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	3,307		3,307		1,621
Term loans amortized cost basis by origination, before current fiscal year	3,573		3,573		770
Term loans amortized cost basis by origination, two years before current fiscal year	1,432		1,432		700
Term loans amortized cost basis by origination, three years before current fiscal year	1,223		1,223		1,079
Term loans amortized cost basis by origination, four years before current fiscal year	1,791		1,791		691
Term loans amortized cost basis by origination, prior	2,199		2,199		596
Amortized Cost Basis	769		769		160
Total	14,294		14,294		5,617
Total commercial and industrial \| Owner-occupied \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	21		21		26
Term loans amortized cost basis by origination, before current fiscal year	49		49		1
Term loans amortized cost basis by origination, two years before current fiscal year	10		10		11
Term loans amortized cost basis by origination, three years before current fiscal year	29		29		13
Term loans amortized cost basis by origination, four years before current fiscal year	10		10		33
Term loans amortized cost basis by origination, prior	97		97		25
Amortized Cost Basis	0		0		0
Total	216		216		109
Total commercial and industrial \| Owner-occupied \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	1		1		0
Term loans amortized cost basis by origination, before current fiscal year	12		12		0
Term loans amortized cost basis by origination, two years before current fiscal year	15		15		3
Term loans amortized cost basis by origination, three years before current fiscal year	15		15		0
Term loans amortized cost basis by origination, four years before current fiscal year	16		16		16
Term loans amortized cost basis by origination, prior	36		36		2
Amortized Cost Basis	2		2		0
Total	97		97		21
Total commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	6,212		6,212		3,270
Term loans amortized cost basis by origination, before current fiscal year	6,349		6,349		1,363
Term loans amortized cost basis by origination, two years before current fiscal year	2,691		2,691		1,133
Term loans amortized cost basis by origination, three years before current fiscal year	1,424		1,424		3,498
Term loans amortized cost basis by origination, four years before current fiscal year	3,967		3,967		1,260
Term loans amortized cost basis by origination, prior	2,936		2,936		592
Amortized Cost Basis	458		458		240
Total	24,037		24,037		11,356
Gross charge-offs
Year One			0		0
Year Two			7		0
Year Three			0		0
Year Four			0		0
Year Five			0		17
Prior			2		1
Amortized Cost Basis			0		0
Total			9		18
Total commercial real estate \| Investment properties
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	5,018		5,018		2,354
Term loans amortized cost basis by origination, before current fiscal year	5,615		5,615		1,069
Term loans amortized cost basis by origination, two years before current fiscal year	2,448		2,448		1,001
Term loans amortized cost basis by origination, three years before current fiscal year	1,269		1,269		3,314
Term loans amortized cost basis by origination, four years before current fiscal year	3,743		3,743		1,124
Term loans amortized cost basis by origination, prior	2,687		2,687		459
Amortized Cost Basis	284		284		175
Total	21,064		21,064		9,496
Gross charge-offs
Year One			0		0
Year Two			7		0
Year Three			0		0
Year Four			0		0
Year Five			0		17
Prior			1		1
Amortized Cost Basis			0		0
Total			8		18
Total commercial real estate \| Investment properties \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	4,989		4,989		2,289
Term loans amortized cost basis by origination, before current fiscal year	5,576		5,576		1,064
Term loans amortized cost basis by origination, two years before current fiscal year	2,392		2,392		995
Term loans amortized cost basis by origination, three years before current fiscal year	1,178		1,178		3,314
Term loans amortized cost basis by origination, four years before current fiscal year	3,613		3,613		1,100
Term loans amortized cost basis by origination, prior	2,529		2,529		447
Amortized Cost Basis	284		284		175
Total	20,561		20,561		9,384
Total commercial real estate \| Investment properties \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	28		28		31
Term loans amortized cost basis by origination, before current fiscal year	8		8		5
Term loans amortized cost basis by origination, two years before current fiscal year	56		56		2
Term loans amortized cost basis by origination, three years before current fiscal year	67		67		0
Term loans amortized cost basis by origination, four years before current fiscal year	100		100		14
Term loans amortized cost basis by origination, prior	49		49		12
Amortized Cost Basis	0		0		0
Total	308		308		64
Total commercial real estate \| Investment properties \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	1		1		34
Term loans amortized cost basis by origination, before current fiscal year	31		31		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0		4
Term loans amortized cost basis by origination, three years before current fiscal year	24		24		0
Term loans amortized cost basis by origination, four years before current fiscal year	30		30		10
Term loans amortized cost basis by origination, prior	109		109		0
Amortized Cost Basis	0		0		0
Total	195		195		48
Total commercial real estate \| 1-4 family properties
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	813		813		622
Term loans amortized cost basis by origination, before current fiscal year	438		438		171
Term loans amortized cost basis by origination, two years before current fiscal year	138		138		99
Term loans amortized cost basis by origination, three years before current fiscal year	120		120		143
Term loans amortized cost basis by origination, four years before current fiscal year	182		182		106
Term loans amortized cost basis by origination, prior	215		215		118
Amortized Cost Basis	89		89		25
Total	1,995		1,995		1,284
Gross charge-offs
Year One			0		0
Year Two			0		0
Year Three			0		0
Year Four			0		0
Year Five			0		0
Prior			1		0
Amortized Cost Basis			0		0
Total			1		0
Total commercial real estate \| 1-4 family properties \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	809		809		615
Term loans amortized cost basis by origination, before current fiscal year	435		435		167
Term loans amortized cost basis by origination, two years before current fiscal year	138		138		99
Term loans amortized cost basis by origination, three years before current fiscal year	118		118		140
Term loans amortized cost basis by origination, four years before current fiscal year	180		180		106
Term loans amortized cost basis by origination, prior	212		212		117
Amortized Cost Basis	89		89		25
Total	1,981		1,981		1,269
Total commercial real estate \| 1-4 family properties \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	4		4		7
Term loans amortized cost basis by origination, before current fiscal year	2		2		4
Term loans amortized cost basis by origination, two years before current fiscal year	0		0		0
Term loans amortized cost basis by origination, three years before current fiscal year	1		1		3
Term loans amortized cost basis by origination, four years before current fiscal year	2		2		0
Term loans amortized cost basis by origination, prior	0		0		0
Amortized Cost Basis	0		0		0
Total	9		9		14
Total commercial real estate \| 1-4 family properties \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0		0
Term loans amortized cost basis by origination, before current fiscal year	1		1		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0		0
Term loans amortized cost basis by origination, three years before current fiscal year	1		1		0
Term loans amortized cost basis by origination, four years before current fiscal year	0		0		0
Term loans amortized cost basis by origination, prior	3		3		1
Amortized Cost Basis	0		0		0
Total	5		5		1
Total commercial real estate \| Land and development
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	381		381		294
Term loans amortized cost basis by origination, before current fiscal year	296		296		123
Term loans amortized cost basis by origination, two years before current fiscal year	105		105		33
Term loans amortized cost basis by origination, three years before current fiscal year	35		35		41
Term loans amortized cost basis by origination, four years before current fiscal year	42		42		30
Term loans amortized cost basis by origination, prior	34		34		15
Amortized Cost Basis	85		85		40
Total	978		978		576
Gross charge-offs
Year One			0		0
Year Two			0		0
Year Three			0		0
Year Four			0		0
Year Five			0		0
Prior			0		0
Amortized Cost Basis			0		0
Total			0		0
Total commercial real estate \| Land and development \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	379		379		294
Term loans amortized cost basis by origination, before current fiscal year	296		296		123
Term loans amortized cost basis by origination, two years before current fiscal year	105		105		33
Term loans amortized cost basis by origination, three years before current fiscal year	34		34		41
Term loans amortized cost basis by origination, four years before current fiscal year	42		42		30
Term loans amortized cost basis by origination, prior	34		34		15
Amortized Cost Basis	85		85		40
Total	975		975		576
Total commercial real estate \| Land and development \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	2		2
Term loans amortized cost basis by origination, before current fiscal year	0		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0
Term loans amortized cost basis by origination, three years before current fiscal year	0		0
Term loans amortized cost basis by origination, four years before current fiscal year	0		0
Term loans amortized cost basis by origination, prior	0		0
Amortized Cost Basis	0		0
Total	2		2
Total commercial real estate \| Land and development \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0
Term loans amortized cost basis by origination, before current fiscal year	0		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0
Term loans amortized cost basis by origination, three years before current fiscal year	1		1
Term loans amortized cost basis by origination, four years before current fiscal year	0		0
Term loans amortized cost basis by origination, prior	0		0
Amortized Cost Basis	0		0
Total	1		1
Total consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	1,784		1,784		1,097
Term loans amortized cost basis by origination, before current fiscal year	1,435		1,435		200
Term loans amortized cost basis by origination, two years before current fiscal year	552		552		351
Term loans amortized cost basis by origination, three years before current fiscal year	863		863		660
Term loans amortized cost basis by origination, four years before current fiscal year	1,362		1,362		789
Term loans amortized cost basis by origination, prior	4,051		4,051		608
Amortized Cost Basis	3,661		3,661		1,797
Total	13,708		13,708		5,502
Gross charge-offs
Year One			0		0
Year Two			6		0
Year Three			4		1
Year Four			5		0
Year Five			2		4
Prior			9		1
Amortized Cost Basis			11		6
Total			37		12
Total consumer \| Consumer mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	1,402		1,402		909
Term loans amortized cost basis by origination, before current fiscal year	1,213		1,213		183
Term loans amortized cost basis by origination, two years before current fiscal year	460		460		336
Term loans amortized cost basis by origination, three years before current fiscal year	779		779		641
Term loans amortized cost basis by origination, four years before current fiscal year	1,087		1,087		763
Term loans amortized cost basis by origination, prior	3,760		3,760		592
Amortized Cost Basis	0		0		32
Total	8,701		8,701		3,456
Gross charge-offs
Year One			0		0
Year Two			0		0
Year Three			0		1
Year Four			1		0
Year Five			0		0
Prior			1		0
Amortized Cost Basis			0		0
Total			2		1
Total consumer \| Consumer mortgages \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	1,402		1,402		908
Term loans amortized cost basis by origination, before current fiscal year	1,206		1,206		181
Term loans amortized cost basis by origination, two years before current fiscal year	456		456		331
Term loans amortized cost basis by origination, three years before current fiscal year	768		768		637
Term loans amortized cost basis by origination, four years before current fiscal year	1,077		1,077		762
Term loans amortized cost basis by origination, prior	3,698		3,698		582
Amortized Cost Basis	0		0		32
Total	8,607		8,607		3,433
Total consumer \| Consumer mortgages \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0		1
Term loans amortized cost basis by origination, before current fiscal year	7		7		2
Term loans amortized cost basis by origination, two years before current fiscal year	4		4		5
Term loans amortized cost basis by origination, three years before current fiscal year	11		11		4
Term loans amortized cost basis by origination, four years before current fiscal year	10		10		1
Term loans amortized cost basis by origination, prior	62		62		10
Amortized Cost Basis	0		0		0
Total	94		94		23
Total consumer \| Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	8		8		1
Term loans amortized cost basis by origination, before current fiscal year	11		11		1
Term loans amortized cost basis by origination, two years before current fiscal year	12		12		1
Term loans amortized cost basis by origination, three years before current fiscal year	30		30		1
Term loans amortized cost basis by origination, four years before current fiscal year	196		196		0
Term loans amortized cost basis by origination, prior	86		86		3
Amortized Cost Basis	2,658		2,658		1,367
Total	3,001		3,001		1,374
Gross charge-offs
Year One			0		0
Year Two			0		0
Year Three			0		0
Year Four			0		0
Year Five			1		0
Prior			2		0
Amortized Cost Basis			2		1
Total			5		1
Total consumer \| Home equity \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	8		8		1
Term loans amortized cost basis by origination, before current fiscal year	10		10		0
Term loans amortized cost basis by origination, two years before current fiscal year	11		11		0
Term loans amortized cost basis by origination, three years before current fiscal year	27		27		0
Term loans amortized cost basis by origination, four years before current fiscal year	191		191		0
Term loans amortized cost basis by origination, prior	80		80		2
Amortized Cost Basis	2,649		2,649		1,365
Total	2,976		2,976		1,368
Total consumer \| Home equity \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0		0
Term loans amortized cost basis by origination, before current fiscal year	1		1		1
Term loans amortized cost basis by origination, two years before current fiscal year	1		1		1
Term loans amortized cost basis by origination, three years before current fiscal year	3		3		1
Term loans amortized cost basis by origination, four years before current fiscal year	5		5		0
Term loans amortized cost basis by origination, prior	6		6		1
Amortized Cost Basis	8		8		2
Total	24		24		6
Total consumer \| Home equity \| Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0
Term loans amortized cost basis by origination, before current fiscal year	0		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0
Term loans amortized cost basis by origination, three years before current fiscal year	0		0
Term loans amortized cost basis by origination, four years before current fiscal year	0		0
Term loans amortized cost basis by origination, prior	0		0
Amortized Cost Basis	1		1
Total	1		1
Total consumer \| Credit cards
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0		0
Term loans amortized cost basis by origination, before current fiscal year	0		0		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0		0
Term loans amortized cost basis by origination, three years before current fiscal year	0		0		0
Term loans amortized cost basis by origination, four years before current fiscal year	0		0		0
Term loans amortized cost basis by origination, prior	0		0		0
Amortized Cost Basis	252		252		53
Total	252		252		53
Gross charge-offs
Year One			0		0
Year Two			0		0
Year Three			0		0
Year Four			0		0
Year Five			0		0
Prior			0		0
Amortized Cost Basis			6		2
Total			6		2
Total consumer \| Credit cards \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0		0
Term loans amortized cost basis by origination, before current fiscal year	0		0		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0		0
Term loans amortized cost basis by origination, three years before current fiscal year	0		0		0
Term loans amortized cost basis by origination, four years before current fiscal year	0		0		0
Term loans amortized cost basis by origination, prior	0		0		0
Amortized Cost Basis	250		250		53
Total	250		250		53
Total consumer \| Credit cards \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0
Term loans amortized cost basis by origination, before current fiscal year	0		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0
Term loans amortized cost basis by origination, three years before current fiscal year	0		0
Term loans amortized cost basis by origination, four years before current fiscal year	0		0
Term loans amortized cost basis by origination, prior	0		0
Amortized Cost Basis	1		1
Total	1		1
Total consumer \| Credit cards \| Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	0		0
Term loans amortized cost basis by origination, before current fiscal year	0		0
Term loans amortized cost basis by origination, two years before current fiscal year	0		0
Term loans amortized cost basis by origination, three years before current fiscal year	0		0
Term loans amortized cost basis by origination, four years before current fiscal year	0		0
Term loans amortized cost basis by origination, prior	0		0
Amortized Cost Basis	1		1
Total	1		1
Total consumer \| Other consumer loans
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	374		374		187
Term loans amortized cost basis by origination, before current fiscal year	211		211		16
Term loans amortized cost basis by origination, two years before current fiscal year	80		80		14
Term loans amortized cost basis by origination, three years before current fiscal year	54		54		18
Term loans amortized cost basis by origination, four years before current fiscal year	79		79		26
Term loans amortized cost basis by origination, prior	205		205		13
Amortized Cost Basis	751		751		345
Total	1,754		1,754		619
Gross charge-offs
Year One			0		0
Year Two			6		0
Year Three			4		0
Year Four			4		0
Year Five			1		4
Prior			6		1
Amortized Cost Basis			3		3
Total			24		8
Total consumer \| Other consumer loans \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Term loans amortized cost basis by origination, current fiscal year	373		373		187

Loans and Allowance for Loan Losses - Schedule of Loan Portfolio Class by Risk Grade and Origination Year (Details) - USD ($)
$ in Millions

3 Months Ended

9 Months Ended

12 Months Ended

Sep. 30, 2026

Sep. 30, 2025

Sep. 30, 2026

Sep. 30, 2025

Dec. 31, 2025

Financing Receivable, Credit Quality Indicator [Line Items]

Term loans amortized cost basis by origination, current fiscal year

$ 18,394