Preferred Stock - Summary (Details) - USD ($) $ / shares in Units, $ in Millions						3 Months Ended		9 Months Ended
	Feb. 01, 2024	Jan. 31, 2024	Aug. 01, 2023	Jul. 31, 2023	Apr. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Class of Stock [Line Items]
Shares (in shares)						2,165,375		2,165,375		2,740,375
Carrying value						$ 21,650		$ 21,650		$ 27,404
Series DD
Class of Stock [Line Items]
Shares (in shares)						169,625		169,625		169,625
Carrying value						$ 1,696		$ 1,696		$ 1,696
Issue date								Sep. 21, 2018
Contractual rate in effect								5.75%
Dividend declared per share (in dollars per share)						$ 143.75	$ 143.75	$ 431.25	$ 431.25
Series DD | Minimum
Class of Stock [Line Items]
Earliest redemption date								Dec. 01, 2023
Series EE
Class of Stock [Line Items]
Shares (in shares)						185,000		185,000		185,000
Carrying value						$ 1,850		$ 1,850		$ 1,850
Issue date								Jan. 24, 2019
Contractual rate in effect								6.00%
Dividend declared per share (in dollars per share)						$ 150.00	150.00	$ 450.00	450.00
Series EE | Minimum
Class of Stock [Line Items]
Earliest redemption date								Mar. 01, 2024
Series GG
Class of Stock [Line Items]
Shares (in shares)						90,000		90,000		90,000
Carrying value						$ 900		$ 900		$ 900
Issue date								Nov. 07, 2019
Contractual rate in effect								4.75%
Dividend declared per share (in dollars per share)						$ 118.75	118.75	$ 356.25	356.25
Series GG | Minimum
Class of Stock [Line Items]
Earliest redemption date								Dec. 01, 2024
Series JJ
Class of Stock [Line Items]
Shares (in shares)						150,000		150,000		150,000
Carrying value						$ 1,500		$ 1,500		$ 1,500
Issue date								Mar. 17, 2021
Contractual rate in effect								4.55%
Dividend declared per share (in dollars per share)						$ 113.75	113.75	$ 341.25	341.25
Series JJ | Minimum
Class of Stock [Line Items]
Earliest redemption date								Jun. 01, 2026
Series LL
Class of Stock [Line Items]
Shares (in shares)						185,000		185,000		185,000
Carrying value						$ 1,850		$ 1,850		$ 1,850
Issue date								May 20, 2021
Contractual rate in effect								4.625%
Dividend declared per share (in dollars per share)						$ 115.63	115.63	$ 346.89	346.89
Series LL | Minimum
Class of Stock [Line Items]
Earliest redemption date								Jun. 01, 2026
Series MM
Class of Stock [Line Items]
Shares (in shares)						200,000		200,000		200,000
Carrying value						$ 2,000		$ 2,000		$ 2,000
Issue date								Jul. 29, 2021
Contractual rate in effect								4.20%
Dividend declared per share (in dollars per share)						$ 105.00	105.00	$ 315.00	315.00
Series MM | Minimum
Class of Stock [Line Items]
Earliest redemption date								Sep. 01, 2026
Series Q
Class of Stock [Line Items]
Shares (in shares)						0		0		150,000
Carrying value						$ 0		$ 0		$ 1,500
Issue date								Apr. 23, 2013
Contractual rate in effect					5.15%
Dividend declared per share (in dollars per share)						$ 0	227.02	$ 220.45	574.25
Dividend rate (in dollars per share)					$ 257.50
Series Q | SOFR
Class of Stock [Line Items]
Floating annualized rate			3.25%					3.25%
Series Q | Minimum
Class of Stock [Line Items]
Earliest redemption date								May 01, 2023
Series R
Class of Stock [Line Items]
Shares (in shares)						0		0		150,000
Carrying value						$ 0		$ 0		$ 1,500
Issue date								Jul. 29, 2013
Contractual rate in effect				6.00%
Dividend declared per share (in dollars per share)						$ 0	228.30	$ 221.70	528.30
Dividend rate (in dollars per share)				$ 300.00
Series R | SOFR
Class of Stock [Line Items]
Floating annualized rate			3.30%					3.30%
Series R | Minimum
Class of Stock [Line Items]
Earliest redemption date								Aug. 01, 2023
Series S
Class of Stock [Line Items]
Shares (in shares)						0		0		200,000
Carrying value						$ 0		$ 0		$ 2,000
Issue date								Jan. 22, 2014
Contractual rate in effect		6.75%
Dividend declared per share (in dollars per share)						$ 0	168.75	$ 233.70	506.25
Dividend rate (in dollars per share)		$ 337.50
Series S | SOFR
Class of Stock [Line Items]
Floating annualized rate	3.78%							3.78%
Series S | Minimum
Class of Stock [Line Items]
Earliest redemption date								Feb. 01, 2024
Series U
Class of Stock [Line Items]
Shares (in shares)						0		0		100,000
Carrying value						$ 0		$ 0		$ 1,000
Issue date								Mar. 10, 2014
Dividend declared per share (in dollars per share)						$ 0	153.13	$ 153.13	459.38
Series U | SOFR
Class of Stock [Line Items]
Floating annualized rate								3.33%
Series U | Minimum
Class of Stock [Line Items]
Earliest redemption date								Apr. 30, 2024
Series X
Class of Stock [Line Items]
Shares (in shares)						160,000		160,000		160,000
Carrying value						$ 1,600		$ 1,600		$ 1,600
Issue date								Sep. 23, 2014
Contractual rate in effect								6.10%
Dividend declared per share (in dollars per share)						$ 152.50	152.50	$ 457.50	457.50
Series X | SOFR
Class of Stock [Line Items]
Floating annualized rate								3.33%
Series X | Minimum
Class of Stock [Line Items]
Earliest redemption date								Oct. 01, 2024
Series CC
Class of Stock [Line Items]
Shares (in shares)						125,750		125,750		125,750
Carrying value						$ 1,258		$ 1,258		$ 1,258
Issue date								Oct. 20, 2017
Dividend declared per share (in dollars per share)						$ 206.73	209.90	$ 619.18	594.05
Series CC | SOFR
Class of Stock [Line Items]
Floating annualized rate								2.58%
Series CC | Minimum
Class of Stock [Line Items]
Earliest redemption date								Nov. 01, 2022
Series FF
Class of Stock [Line Items]
Shares (in shares)						0		0		225,000
Carrying value						$ 0		$ 0		$ 2,250
Issue date								Jul. 31, 2019
Dividend declared per share (in dollars per share)						$ 0	125.00	$ 250.00	375.00
Series FF | SOFR
Class of Stock [Line Items]
Floating annualized rate								3.38%
Series FF | Minimum
Class of Stock [Line Items]
Earliest redemption date								Aug. 01, 2024
Series HH
Class of Stock [Line Items]
Shares (in shares)						300,000		300,000		300,000
Carrying value						$ 3,000		$ 3,000		$ 3,000
Issue date								Jan. 23, 2020
Contractual rate in effect								4.60%
Dividend declared per share (in dollars per share)						$ 115.00	115.00	$ 345.00	345.00
Series HH | SOFR
Class of Stock [Line Items]
Floating annualized rate								3.125%
Series HH | Minimum
Class of Stock [Line Items]
Earliest redemption date								Feb. 01, 2025
Series II
Class of Stock [Line Items]
Shares (in shares)						150,000		150,000		150,000
Carrying value						$ 1,500		$ 1,500		$ 1,500
Issue date								Feb. 24, 2020
Contractual rate in effect								4.00%
Dividend declared per share (in dollars per share)						$ 100.00	100.00	$ 300.00	300.00
Series II | SOFR
Class of Stock [Line Items]
Floating annualized rate								2.745%
Series II | Minimum
Class of Stock [Line Items]
Earliest redemption date								Apr. 01, 2025
Series KK
Class of Stock [Line Items]
Shares (in shares)						200,000		200,000		200,000
Carrying value						$ 2,000		$ 2,000		$ 2,000
Issue date								May 12, 2021
Contractual rate in effect								3.65%
Dividend declared per share (in dollars per share)						$ 91.25	$ 91.25	$ 273.75	$ 273.75
Series KK | CMT
Class of Stock [Line Items]
Floating annualized rate								2.85%
Series KK | Minimum
Class of Stock [Line Items]
Earliest redemption date								Jun. 01, 2026
Series NN
Class of Stock [Line Items]
Shares (in shares)						250,000		250,000
Carrying value						$ 2,496		$ 2,496
Issue date								Mar. 12, 2024
Contractual rate in effect								6.875%
Dividend declared per share (in dollars per share)						$ 171.88		$ 322.75
Series NN | CMT
Class of Stock [Line Items]
Floating annualized rate								2.737%
Series NN | Minimum
Class of Stock [Line Items]
Earliest redemption date								Jun. 01, 2029