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	Jun. 30, 2026	Dec. 31, 2025
Affordable housing partnership, tax credit and CRA investments, net:
Total affordable housing partnership, tax credit and CRA investments, net	$ 919,230	$ 969,492
Derivative assets:
Gross derivative assets	387,420	409,467
Net derivative assets	80,070	151,942
Gross derivative liabilities	407,529	385,973
Net derivative liabilities	300,865	284,333
Fair value	14,581,546	13,212,220
Government National Mortgage Association (GNMA)
Derivative assets:
Fair value	9,900,000	9,600,000
U.S. Treasury securities
Derivative assets:
Fair value	1,431,341	993,913
U.S. government agency and U.S. government-sponsored enterprise debt securities
Derivative assets:
Fair value	254,400	257,654
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities
Derivative assets:
Fair value	224,397	265,338
U.S. government agency and U.S. government-sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities
Derivative assets:
Fair value	11,230,828	10,132,653
Municipal securities
Derivative assets:
Fair value	240,688	243,102
Non-agency commercial mortgage-backed securities
Derivative assets:
Fair value	174,606	190,948
Non-agency residential mortgage-backed securities
Derivative assets:
Fair value	361,635	393,787
Corporate debt securities
Derivative assets:
Fair value	421,302	464,981
Foreign government bonds
Derivative assets:
Fair value	242,349	238,455
Asset-backed securities
Derivative assets:
Fair value		31,389
Fair Value, Measurements, Recurring
AFS debt securities:
Fair Value	14,581,546	13,212,220
Affordable housing partnership, tax credit and CRA investments, net:
Equity securities	26,436	26,396
Total affordable housing partnership, tax credit and CRA investments, net	26,436	26,396
Other assets:
Equity securities	195	630
Total other assets	195	630
Derivative assets:
Gross derivative assets	387,420	409,467
Netting adjustments	(307,350)	(257,525)
Net derivative assets	80,070	151,942
Gross derivative liabilities	407,529	385,973
Netting adjustments	(106,664)	(101,640)
Net derivative liabilities	300,865	284,333
Fair Value, Measurements, Recurring | Interest rate contracts
Derivative assets:
Gross derivative assets	261,527	298,558
Gross derivative liabilities	268,367	256,870
Fair Value, Measurements, Recurring | Foreign exchange contracts
Derivative assets:
Gross derivative assets	60,269	44,340
Gross derivative liabilities	56,384	43,160
Fair Value, Measurements, Recurring | Credit contracts
Derivative assets:
Gross derivative assets	6	25
Gross derivative liabilities	130	51
Fair Value, Measurements, Recurring | Equity contracts
Derivative assets:
Gross derivative assets	524	522
Gross derivative liabilities	15,775	13,734
Fair Value, Measurements, Recurring | Commodity contracts
Derivative assets:
Gross derivative assets	65,094	66,022
Gross derivative liabilities	66,873	72,158
Fair Value, Measurements, Recurring | U.S. Treasury securities
AFS debt securities:
Fair Value	1,431,341	993,913
Fair Value, Measurements, Recurring | U.S. government agency and U.S. government-sponsored enterprise debt securities
AFS debt securities:
Fair Value	254,400	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	224,397	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	11,230,828	10,132,653
Fair Value, Measurements, Recurring | Municipal securities
AFS debt securities:
Fair Value	240,688	243,102
Fair Value, Measurements, Recurring | Non-agency commercial mortgage-backed securities
AFS debt securities:
Fair Value	174,606	190,948
Fair Value, Measurements, Recurring | Non-agency residential mortgage-backed securities
AFS debt securities:
Fair Value	361,635	393,787
Fair Value, Measurements, Recurring | Corporate debt securities
AFS debt securities:
Fair Value	421,302	464,981
Fair Value, Measurements, Recurring | Foreign government bonds
AFS debt securities:
Fair Value	242,349	238,455
Fair Value, Measurements, Recurring | Asset-backed securities
AFS debt securities:
Fair Value		31,389
Fair Value, Measurements, Recurring | Level 1
AFS debt securities:
Fair Value	1,431,341	993,913
Affordable housing partnership, tax credit and CRA investments, net:
Equity securities	22,174	22,098
Total affordable housing partnership, tax credit and CRA investments, net	22,174	22,098
Other assets:
Equity securities	195	630
Total other assets	195	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	1,431,341	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
Fair Value, Measurements, Recurring | Level 2
AFS debt securities:
Fair Value	13,150,205	12,218,307
Affordable housing partnership, tax credit and CRA investments, net:
Equity securities	4,262	4,298
Total affordable housing partnership, tax credit and CRA investments, net	4,262	4,298
Other assets:
Equity securities	0	0
Total other assets	0	0
Derivative assets:
Gross derivative assets	386,896	408,945
Netting adjustments	(307,350)	(257,525)
Net derivative assets	79,546	151,420
Gross derivative liabilities	391,754	372,239
Netting adjustments	(106,664)	(101,640)
Net derivative liabilities	285,090	270,599
Fair Value, Measurements, Recurring | Level 2 | Interest rate contracts
Derivative assets:
Gross derivative assets	261,527	298,558
Gross derivative liabilities	268,367	256,870
Fair Value, Measurements, Recurring | Level 2 | Foreign exchange contracts
Derivative assets:
Gross derivative assets	60,269	44,340
Gross derivative liabilities	56,384	43,160
Fair Value, Measurements, Recurring | Level 2 | Credit contracts
Derivative assets:
Gross derivative assets	6	25
Gross derivative liabilities	130	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	65,094	66,022
Gross derivative liabilities	66,873	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	254,400	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	224,397	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	11,230,828	10,132,653
Fair Value, Measurements, Recurring | Level 2 | Municipal securities
AFS debt securities:
Fair Value	240,688	243,102
Fair Value, Measurements, Recurring | Level 2 | Non-agency commercial mortgage-backed securities
AFS debt securities:
Fair Value	174,606	190,948
Fair Value, Measurements, Recurring | Level 2 | Non-agency residential mortgage-backed securities
AFS debt securities:
Fair Value	361,635	393,787
Fair Value, Measurements, Recurring | Level 2 | Corporate debt securities
AFS debt securities:
Fair Value	421,302	464,981
Fair Value, Measurements, Recurring | Level 2 | Foreign government bonds
AFS debt securities:
Fair Value	242,349	238,455
Fair Value, Measurements, Recurring | Level 2 | Asset-backed securities
AFS debt securities:
Fair Value		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	524	522
Netting adjustments	0	0
Net derivative assets	524	522
Gross derivative liabilities	15,775	13,734
Netting adjustments	0	0
Net derivative liabilities	15,775	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	524	522
Gross derivative liabilities	15,775	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