Investment Securities - Summary of Amortized Cost of Held-to-Maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	$ 8,192,822	$ 8,444,362
Agency CMO
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	18,246	19,847
Agency MBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	2,954,301	3,109,411
Agency CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	4,315,250	4,357,505
Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	839,766	891,909
CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	65,259	65,690
Aaa
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	366,566	406,877
Aaa | Agency CMO
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aaa | Agency MBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aaa | Agency CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aaa | Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	301,307	341,187
Aaa | CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	65,259	65,690
Aa1
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	7,441,517	7,645,090
Aa1 | Agency CMO
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	18,246	19,847
Aa1 | Agency MBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	2,954,301	3,109,411
Aa1 | Agency CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	4,315,250	4,357,505
Aa1 | Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	153,720	158,327
Aa1 | CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aa2
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	244,918	230,986
Aa2 | Agency CMO
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aa2 | Agency MBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aa2 | Agency CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aa2 | Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	244,918	230,986
Aa2 | CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aa3
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	112,768	128,692
Aa3 | Agency CMO
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aa3 | Agency MBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aa3 | Agency CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Aa3 | Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	112,768	128,692
Aa3 | CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A1
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	10,444	13,761
A1 | Agency CMO
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A1 | Agency MBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A1 | Agency CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A1 | Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	10,444	13,761
A1 | CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A2
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	4,165	0
A2 | Agency CMO
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A2 | Agency MBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A2 | Agency CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A2 | Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	4,165	0
A2 | CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A3
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	4,165
A3 | Agency CMO
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A3 | Agency MBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A3 | Agency CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
A3 | Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	4,165
A3 | CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Not Rated
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	12,444	14,791
Not Rated | Agency CMO
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Not Rated | Agency MBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Not Rated | Agency CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	0	0
Not Rated | Municipal bonds and notes
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	12,444	14,791
Not Rated | CMBS
Debt Securities, Held-to-maturity, Allowance for Credit Loss [Line Items]
Total held-to-maturity	$ 0	$ 0