Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended
	Feb. 01, 2022	Jun. 01, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			3,283,750		3,483,750
Carrying value			$ 32,838		$ 34,838
Liquidation value and redemption price per share (in dollars per share)			$ 10,000
Aggregate liquidation value			$ 33,200
Series AA
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			0		0
Carrying value			$ 0		$ 0
Issue date			Jun. 04, 2015
Contractual rate in effect		6.10%	0.00%
Dividend declared per share (in dollars per share)			$ 0	$ 152.50
Preferred stock redeemed		$ 1,430
Series AA | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Sep. 01, 2020
Series BB
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			0		0
Carrying value			$ 0		$ 0
Issue date			Jul. 29, 2015
Contractual rate in effect		6.15%	0.00%
Dividend declared per share (in dollars per share)			$ 0	153.75
Preferred stock redeemed		$ 1,150
Series BB | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Sep. 01, 2020
Series DD
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			169,625		169,625
Carrying value			$ 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
Series DD | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Dec. 01, 2023
Series EE
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			185,000		185,000
Carrying value			$ 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
Series EE | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Mar. 01, 2024
Series GG
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			90,000		90,000
Carrying value			$ 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
Series GG | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Dec. 01, 2024
Series JJ
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			150,000		150,000
Carrying value			$ 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
Series JJ | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Jun. 01, 2026
Series LL
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			185,000		185,000
Carrying value			$ 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
Series LL | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Jun. 01, 2026
Series MM
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			200,000		200,000
Carrying value			$ 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
Series MM | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Sep. 01, 2026
Series I
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			293,375		293,375
Carrying value			$ 2,934		$ 2,934
Issue date			Apr. 23, 2008
Dividend declared per share (in dollars per share)			$ 92.13	93.06
Series I | Three-month LIBOR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			3.47%
Series I | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Apr. 30, 2018
Series Q
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			150,000		150,000
Carrying value			$ 1,500		$ 1,500
Issue date			Apr. 23, 2013
Contractual rate in effect			5.15%
Dividend declared per share (in dollars per share)			$ 128.75	128.75
Series Q | Three-month LIBOR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			3.25%
Series Q | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			May 01, 2023
Series R
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			150,000		150,000
Carrying value			$ 1,500		$ 1,500
Issue date			Jul. 29, 2013
Contractual rate in effect			6.00%
Dividend declared per share (in dollars per share)			$ 150.00	150.00
Series R | Three-month LIBOR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			3.30%
Series R | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Aug. 01, 2023
Series S
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			200,000		200,000
Carrying value			$ 2,000		$ 2,000
Issue date			Jan. 22, 2014
Contractual rate in effect			6.75%
Dividend declared per share (in dollars per share)			$ 168.75	168.75
Series S | Three-month LIBOR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			3.78%
Series S | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Feb. 01, 2024
Series U
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			100,000		100,000
Carrying value			$ 1,000		$ 1,000
Issue date			Mar. 10, 2014
Contractual rate in effect			6.125%
Dividend declared per share (in dollars per share)			$ 153.13	153.13
Series U | Three-month LIBOR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			3.33%
Series U | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Apr. 30, 2024
Series V
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			250,000		250,000
Carrying value			$ 2,500		$ 2,500
Issue date			Jun. 09, 2014
Dividend declared per share (in dollars per share)			$ 86.40	85.97
Series V | Three-month LIBOR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			3.32%
Series V | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Jul. 01, 2019
Series X
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			160,000		160,000
Carrying value			$ 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
Series X | Three-month LIBOR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			3.33%
Series X | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Oct. 01, 2024
Series Z
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			0		200,000
Carrying value			$ 0		$ 2,000
Issue date			Apr. 21, 2015
Contractual rate in effect			0.00%
Dividend declared per share (in dollars per share)			$ 0	101.24
Preferred stock redeemed	$ 2,000
Series Z | Three-month LIBOR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			3.80%
Series Z | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			May 01, 2020
Series CC
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			125,750		125,750
Carrying value			$ 1,258		$ 1,258
Issue date			Oct. 20, 2017
Contractual rate in effect			4.625%
Dividend declared per share (in dollars per share)			$ 115.63	115.63
Series CC | Three-month LIBOR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			2.58%
Series CC | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Nov. 01, 2022
Series FF
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			225,000		225,000
Carrying value			$ 2,250		$ 2,250
Issue date			Jul. 31, 2019
Contractual rate in effect			5.00%
Dividend declared per share (in dollars per share)			$ 125.00	125.00
Series FF | Three-month term SOFR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			3.38%
Series FF | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Aug. 01, 2024
Series HH
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			300,000		300,000
Carrying value			$ 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
Series HH | Three-month term SOFR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			3.125%
Series HH | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Feb. 01, 2025
Series II
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			150,000		150,000
Carrying value			$ 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
Series II | Three-month term SOFR
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			2.745%
Series II | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Apr. 01, 2025
Series KK
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shares (in shares)			200,000		200,000
Carrying value			$ 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
Series KK | Five-year CMT
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock dividend rate, variable, basis spread			2.85%
Series KK | Minimum
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Earliest redemption date			Jun. 01, 2026