Fair Value Measurement and Fair Value of Financial Instruments - Schedule of Financial Assets (Liabilities) Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Affordable housing partnership, tax credit and CRA investments, net:
Total affordable housing partnership, tax credit and CRA investments, net	$ 983,976	$ 969,492
Derivative assets:
Gross derivative assets	470,335	409,467
Net derivative assets	188,442	151,942
Gross derivative liabilities	433,751	385,973
Net derivative liabilities	304,366	284,333
Fair value	14,093,483	13,212,220
Government National Mortgage Association (GNMA)
Derivative assets:
Fair value	10,300,000	9,600,000
U.S. Treasury securities
Derivative assets:
Fair value	1,237,787	993,913
U.S. government agency and U.S. government-sponsored enterprise debt securities
Derivative assets:
Fair value	255,863	257,654
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
Derivative assets:
Fair value	250,662	265,338
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
Derivative assets:
Fair value	10,844,437	10,132,653
Municipal securities
Derivative assets:
Fair value	237,959	243,102
Non-agency commercial mortgage-backed securities
Derivative assets:
Fair value	174,870	190,948
Non-agency residential mortgage-backed securities
Derivative assets:
Fair value	373,497	393,787
Corporate debt securities
Derivative assets:
Fair value	447,583	464,981
Foreign government bonds
Derivative assets:
Fair value	240,395	238,455
Asset-backed securities
Derivative assets:
Fair value	30,430	31,389
Fair Value, Measurements, Recurring
AFS debt securities:
Fair Value	14,093,483	13,212,220
Affordable housing partnership, tax credit and CRA investments, net:
Equity securities	26,406	26,396
Total affordable housing partnership, tax credit and CRA investments, net	26,406	26,396
Other assets:
Equity securities	543	630
Total other assets	543	630
Derivative assets:
Gross derivative assets	470,335	409,467
Netting adjustments	(281,893)	(257,525)
Net derivative assets	188,442	151,942
Gross derivative liabilities	433,751	385,973
Netting adjustments	(129,385)	(101,640)
Net derivative liabilities	304,366	284,333
Fair Value, Measurements, Recurring | Interest rate contracts
Derivative assets:
Gross derivative assets	267,748	298,558
Gross derivative liabilities	248,497	256,870
Fair Value, Measurements, Recurring | Foreign exchange contracts
Derivative assets:
Gross derivative assets	55,603	44,340
Gross derivative liabilities	49,991	43,160
Fair Value, Measurements, Recurring | Credit contracts
Derivative assets:
Gross derivative assets	16	25
Gross derivative liabilities	129	51
Fair Value, Measurements, Recurring | Equity contracts
Derivative assets:
Gross derivative assets	583	522
Gross derivative liabilities	13,046	13,734
Fair Value, Measurements, Recurring | Commodity contracts
Derivative assets:
Gross derivative assets	146,385	66,022
Gross derivative liabilities	122,088	72,158
Fair Value, Measurements, Recurring | U.S. Treasury securities
AFS debt securities:
Fair Value	1,237,787	993,913
Fair Value, Measurements, Recurring | U.S. government agency and U.S. government-sponsored enterprise debt securities
AFS debt securities:
Fair Value	255,863	257,654
Fair Value, Measurements, Recurring | U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
AFS debt securities:
Fair Value	250,662	265,338
Fair Value, Measurements, Recurring | U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
AFS debt securities:
Fair Value	10,844,437	10,132,653
Fair Value, Measurements, Recurring | Municipal securities
AFS debt securities:
Fair Value	237,959	243,102
Fair Value, Measurements, Recurring | Non-agency commercial mortgage-backed securities
AFS debt securities:
Fair Value	174,870	190,948
Fair Value, Measurements, Recurring | Non-agency residential mortgage-backed securities
AFS debt securities:
Fair Value	373,497	393,787
Fair Value, Measurements, Recurring | Corporate debt securities
AFS debt securities:
Fair Value	447,583	464,981
Fair Value, Measurements, Recurring | Foreign government bonds
AFS debt securities:
Fair Value	240,395	238,455
Fair Value, Measurements, Recurring | Asset-backed securities
AFS debt securities:
Fair Value	30,430	31,389
Fair Value, Measurements, Recurring | Level 1
AFS debt securities:
Fair Value	1,237,787	993,913
Affordable housing partnership, tax credit and CRA investments, net:
Equity securities	22,112	22,098
Total affordable housing partnership, tax credit and CRA investments, net	22,112	22,098
Other assets:
Equity securities	543	630
Total other assets	543	630
Derivative assets:
Gross derivative assets	0	0
Netting adjustments	0	0
Net derivative assets	0	0
Gross derivative liabilities	0	0
Netting adjustments	0	0
Net derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 1 | Interest rate contracts
Derivative assets:
Gross derivative assets	0	0
Gross derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 1 | Foreign exchange contracts
Derivative assets:
Gross derivative assets	0	0
Gross derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 1 | Credit contracts
Derivative assets:
Gross derivative assets	0	0
Gross derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 1 | Equity contracts
Derivative assets:
Gross derivative assets	0	0
Gross derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 1 | Commodity contracts
Derivative assets:
Gross derivative assets	0	0
Gross derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury securities
AFS debt securities:
Fair Value	1,237,787	993,913
Fair Value, Measurements, Recurring | Level 1 | U.S. government agency and U.S. government-sponsored enterprise debt securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | Municipal securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | Non-agency commercial mortgage-backed securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | Non-agency residential mortgage-backed securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | Corporate debt securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | Foreign government bonds
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 1 | Asset-backed securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 2
AFS debt securities:
Fair Value	12,855,696	12,218,307
Affordable housing partnership, tax credit and CRA investments, net:
Equity securities	4,294	4,298
Total affordable housing partnership, tax credit and CRA investments, net	4,294	4,298
Other assets:
Equity securities	0	0
Total other assets	0	0
Derivative assets:
Gross derivative assets	469,752	408,945
Netting adjustments	(281,893)	(257,525)
Net derivative assets	187,859	151,420
Gross derivative liabilities	420,705	372,239
Netting adjustments	(129,385)	(101,640)
Net derivative liabilities	291,320	270,599
Fair Value, Measurements, Recurring | Level 2 | Interest rate contracts
Derivative assets:
Gross derivative assets	267,748	298,558
Gross derivative liabilities	248,497	256,870
Fair Value, Measurements, Recurring | Level 2 | Foreign exchange contracts
Derivative assets:
Gross derivative assets	55,603	44,340
Gross derivative liabilities	49,991	43,160
Fair Value, Measurements, Recurring | Level 2 | Credit contracts
Derivative assets:
Gross derivative assets	16	25
Gross derivative liabilities	129	51
Fair Value, Measurements, Recurring | Level 2 | Equity contracts
Derivative assets:
Gross derivative assets	0	0
Gross derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 2 | Commodity contracts
Derivative assets:
Gross derivative assets	146,385	66,022
Gross derivative liabilities	122,088	72,158
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasury securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 2 | U.S. government agency and U.S. government-sponsored enterprise debt securities
AFS debt securities:
Fair Value	255,863	257,654
Fair Value, Measurements, Recurring | Level 2 | U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
AFS debt securities:
Fair Value	250,662	265,338
Fair Value, Measurements, Recurring | Level 2 | U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
AFS debt securities:
Fair Value	10,844,437	10,132,653
Fair Value, Measurements, Recurring | Level 2 | Municipal securities
AFS debt securities:
Fair Value	237,959	243,102
Fair Value, Measurements, Recurring | Level 2 | Non-agency commercial mortgage-backed securities
AFS debt securities:
Fair Value	174,870	190,948
Fair Value, Measurements, Recurring | Level 2 | Non-agency residential mortgage-backed securities
AFS debt securities:
Fair Value	373,497	393,787
Fair Value, Measurements, Recurring | Level 2 | Corporate debt securities
AFS debt securities:
Fair Value	447,583	464,981
Fair Value, Measurements, Recurring | Level 2 | Foreign government bonds
AFS debt securities:
Fair Value	240,395	238,455
Fair Value, Measurements, Recurring | Level 2 | Asset-backed securities
AFS debt securities:
Fair Value	30,430	31,389
Fair Value, Measurements, Recurring | Level 3
AFS debt securities:
Fair Value	0	0
Affordable housing partnership, tax credit and CRA investments, net:
Equity securities	0	0
Total affordable housing partnership, tax credit and CRA investments, net	0	0
Other assets:
Equity securities	0	0
Total other assets	0	0
Derivative assets:
Gross derivative assets	583	522
Netting adjustments	0	0
Net derivative assets	583	522
Gross derivative liabilities	13,046	13,734
Netting adjustments	0	0
Net derivative liabilities	13,046	13,734
Fair Value, Measurements, Recurring | Level 3 | Interest rate contracts
Derivative assets:
Gross derivative assets	0	0
Gross derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 3 | Foreign exchange contracts
Derivative assets:
Gross derivative assets	0	0
Gross derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 3 | Credit contracts
Derivative assets:
Gross derivative assets	0	0
Gross derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 3 | Equity contracts
Derivative assets:
Gross derivative assets	583	522
Gross derivative liabilities	13,046	13,734
Fair Value, Measurements, Recurring | Level 3 | Commodity contracts
Derivative assets:
Gross derivative assets	0	0
Gross derivative liabilities	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. Treasury securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. government agency and U.S. government-sponsored enterprise debt securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Municipal securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Non-agency commercial mortgage-backed securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Non-agency residential mortgage-backed securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Corporate debt securities
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Foreign government bonds
AFS debt securities:
Fair Value	0	0
Fair Value, Measurements, Recurring | Level 3 | Asset-backed securities
AFS debt securities:
Fair Value	$ 0	$ 0