Fair Value Measurements - Summary of Fair Values of Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands		Jun. 30, 2025	Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value	[1]	$ 9,620,354	$ 9,006,600
Total derivative instruments, after netting		73,050	19,049
Originated loans held for sale		$ 75	$ 297
Derivative Liability Statement Of Financial Position Extensible Enumeration Not Disclosed Flag		true	true
Derivative Liability		$ 168,029	$ 279,600
Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		9,620,354	9,006,600
Alternative investments measured at NAV		50,453	43,360
Total financial assets		9,931,337	9,365,837
Derivative Liability		243,787	311,561
Contingent consideration		182	11,750
Total financial liabilities		243,969	323,311
Fair Value, Recurring | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative instruments, after netting		247,555	302,142
Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Alternative investments measured at NAV		0	0
Total financial assets		13,435	14,701
Derivative Liability		1,515	43
Contingent consideration		0	0
Total financial liabilities		1,515	43
Fair Value, Recurring | Level 1 | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative instruments, after netting		535	1,263
Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		9,620,354	9,006,600
Alternative investments measured at NAV		0	0
Total financial assets		9,867,449	9,307,776
Derivative Liability		242,272	311,518
Contingent consideration		0	0
Total financial liabilities		242,272	311,518
Fair Value, Recurring | Level 2 | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative instruments, after netting		247,020	300,879
Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Alternative investments measured at NAV		0	0
Total financial assets		0	0
Derivative Liability		0	0
Contingent consideration		182	11,750
Total financial liabilities		182	11,750
Fair Value, Recurring | Level 3 | Derivative instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total derivative instruments, after netting		0	0
Originated loans held for sale | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Originated loans held for sale		75	297
Originated loans held for sale | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Originated loans held for sale		0	0
Originated loans held for sale | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Originated loans held for sale		75	297
Originated loans held for sale | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Originated loans held for sale		0	0
Investments held in Rabbi Trusts | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments held in Rabbi Trust		12,900	13,438
Investments held in Rabbi Trusts | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments held in Rabbi Trust		12,900	13,438
Investments held in Rabbi Trusts | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments held in Rabbi Trust		0	0
Investments held in Rabbi Trusts | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments held in Rabbi Trust		0	0
Government agency debentures
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		192,436	186,426
Government agency debentures | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		192,436	186,426
Government agency debentures | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Government agency debentures | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		192,436	186,426
Government agency debentures | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Municipal bonds and notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		103,808	110,876
Municipal bonds and notes | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		103,808	110,876
Municipal bonds and notes | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Municipal bonds and notes | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		103,808	110,876
Municipal bonds and notes | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Agency CMO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		27,113	29,043
Agency CMO | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		27,113	29,043
Agency CMO | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Agency CMO | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		27,113	29,043
Agency CMO | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Agency MBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		4,831,605	4,519,785
Agency MBS | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		4,831,605	4,519,785
Agency MBS | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Agency MBS | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		4,831,605	4,519,785
Agency MBS | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Agency CMBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		3,224,198	3,034,392
Agency CMBS | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		3,224,198	3,034,392
Agency CMBS | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Agency CMBS | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		3,224,198	3,034,392
Agency CMBS | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
CMBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		790,132	625,388
CMBS | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		790,132	625,388
CMBS | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
CMBS | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		790,132	625,388
CMBS | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Corporate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		403,373	452,266
Corporate debt | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		403,373	452,266
Corporate debt | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Corporate debt | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		403,373	452,266
Corporate debt | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Private label MBS
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		38,364	39,219
Private label MBS | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		38,364	39,219
Private label MBS | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Private label MBS | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		38,364	39,219
Private label MBS | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		9,325	9,205
Other | Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		9,325	9,205
Other | Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		0	0
Other | Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		9,325	9,205
Other | Fair Value, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale, at fair value		$ 0	$ 0

[1] Investment securities available-for-sale had an amortized cost basis of $10,189,481 at June 30, 2025, and $9,720,415 at December 31, 2024.