Derivative Instruments and Hedging Activities - Balance Sheet Disclosures (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025	Dec. 31, 2024
Derivative [Line Items]
Other Assets	$ 265,370	$ 182,673
Other Liabilities	264,214	184,162
Notional Amount	23,589,104	22,489,009
Derivatives designated as hedging instruments: \| Fair value hedge interest rate swaps \| Interest rate swaps
Derivative [Line Items]
Other Assets	932	1,319
Other Liabilities	263	4,088
Notional Amount	415,088	780,322
Derivatives not designated as hedging instruments:
Derivative [Line Items]
Other Assets	264,438	181,354
Other Liabilities	263,951	180,074
Notional Amount	23,174,016	21,708,687
Derivatives not designated as hedging instruments: \| Interest rate swaps
Derivative [Line Items]
Other Assets	238,836	162,191
Other Liabilities	238,692	161,911
Notional Amount	19,540,317	18,685,777
Derivatives not designated as hedging instruments: \| Foreign currency derivatives
Derivative [Line Items]
Other Assets	25,575	19,140
Other Liabilities	25,082	18,031
Notional Amount	3,133,435	2,343,733
Derivatives not designated as hedging instruments: \| Mortgage banking derivatives
Derivative [Line Items]
Other Assets	27	23
Other Liabilities	125	78
Notional Amount	28,350	25,718
Derivatives not designated as hedging instruments: \| Credit default swap
Derivative [Line Items]
Other Assets	0	0
Other Liabilities	52	54
Notional Amount	471,914	$ 653,459	$ 1,500,000
Derivatives not designated as hedging instruments: \| Fair value hedge interest rate swaps \| Interest rate swaps
Derivative [Line Items]
Notional Amount	$ 10,400