XML 43 R36.htm IDEA: XBRL DOCUMENT v3.24.3
Investment Securities - Summary of Amortized Cost and Estimated Fair Value of Investment Securities (Detail) - USD ($)
$ in Thousands
Sep. 30, 2024
Dec. 31, 2023
Sep. 30, 2023
Dec. 31, 2022
Schedule of Investments [Line Items]        
Amortized Cost, Available-for-sale $ 2,818,313 $ 3,398,942 $ 2,818,313 $ 3,398,942
Gross Unrealized Holding Gain, Available-for-sale 15,256 7,050    
Gross Unrealized Holding Loss, Available-for-sale (367,984) (449,867)    
Investment securities available-for-sale $ 2,465,585 $ 2,956,125    
Total Percent, Available-for-sale 100.00% 100.00%    
Amortized Cost, Held-to-maturity $ 2,405,254 $ 2,464,610    
Gross Unrealized Holding Gain, Held-to-maturity 2,999 3,438    
Gross Unrealized Holding Loss, Held-to-maturity (344,559) (385,167)    
Fair Value, Held-to-maturity $ 2,063,694 $ 2,082,881 $ 2,063,694 $ 2,082,881
Total Percent, Held-to-maturity 100.00% 100.00%    
Government Agency/GSE [Member]        
Schedule of Investments [Line Items]        
Amortized Cost, Available-for-sale $ 33,921 $ 32,229    
Gross Unrealized Holding Gain, Available-for-sale 208 24    
Gross Unrealized Holding Loss, Available-for-sale 0 0    
Investment securities available-for-sale $ 34,129 $ 32,253    
Total Percent, Available-for-sale 1.38% 1.09%    
Amortized Cost, Held-to-maturity $ 518,446 $ 530,656    
Gross Unrealized Holding Gain, Held-to-maturity 0    
Gross Unrealized Holding Loss, Held-to-maturity (84,898) (97,972)    
Fair Value, Held-to-maturity $ 433,548 $ 432,684    
Total Percent, Held-to-maturity 21.55% 21.53%    
Mortgage-backed Securities [Member]        
Schedule of Investments [Line Items]        
Amortized Cost, Available-for-sale $ 2,295,381 $ 2,843,744    
Gross Unrealized Holding Gain, Available-for-sale 43 42    
Gross Unrealized Holding Loss, Available-for-sale (261,825) (336,107)    
Investment securities available-for-sale $ 2,033,599 $ 2,507,679    
Total Percent, Available-for-sale 82.48% 84.83%    
Amortized Cost, Held-to-maturity $ 626,474 $ 663,090    
Gross Unrealized Holding Gain, Held-to-maturity 5 0    
Gross Unrealized Holding Loss, Held-to-maturity (85,320) (97,436)    
Fair Value, Held-to-maturity $ 541,159 $ 565,654    
Total Percent, Held-to-maturity 26.05% 26.90%    
CMO/REMIC        
Schedule of Investments [Line Items]        
Amortized Cost, Available-for-sale $ 476,051 $ 502,234    
Gross Unrealized Holding Gain, Available-for-sale 0 0    
Gross Unrealized Holding Loss, Available-for-sale (105,044) (112,872)    
Investment securities available-for-sale $ 371,007 $ 389,362    
Total Percent, Available-for-sale 15.05% 13.17%    
Amortized Cost, Held-to-maturity $ 788,622 $ 802,892    
Gross Unrealized Holding Gain, Held-to-maturity 0    
Gross Unrealized Holding Loss, Held-to-maturity (144,801) (156,155)    
Fair Value, Held-to-maturity $ 643,821 $ 646,737    
Total Percent, Held-to-maturity 32.79% 32.58%    
Municipal Bonds [Member]        
Schedule of Investments [Line Items]        
Amortized Cost, Available-for-sale $ 26,489 $ 26,477    
Gross Unrealized Holding Gain, Available-for-sale 46 46    
Gross Unrealized Holding Loss, Available-for-sale (1,115) (888)    
Investment securities available-for-sale $ 25,420 $ 25,635    
Total Percent, Available-for-sale 1.03% 0.87%    
Amortized Cost, Held-to-maturity $ 460,257 $ 467,972    
Gross Unrealized Holding Gain, Held-to-maturity 2,994 3,438    
Gross Unrealized Holding Loss, Held-to-maturity (29,540) (33,604)    
Fair Value, Held-to-maturity $ 433,711 $ 437,806    
Total Percent, Held-to-maturity 19.14% 18.99%    
Other Securities [Member]        
Schedule of Investments [Line Items]        
Amortized Cost, Available-for-sale $ 1,430 $ 1,196    
Gross Unrealized Holding Gain, Available-for-sale 0 0    
Gross Unrealized Holding Loss, Available-for-sale 0 0    
Investment securities available-for-sale $ 1,430 $ 1,196    
Total Percent, Available-for-sale 0.06% 0.04%    
Amortized Cost, Held-to-maturity [1] $ 11,455      
Gross Unrealized Holding Gain, Held-to-maturity 0      
Gross Unrealized Holding Loss, Held-to-maturity 0      
Fair Value, Held-to-maturity [1] $ 11,455      
Total Percent, Held-to-maturity [1] 0.47%      
Unallocated Portfolio Layer Fair Value [Member]        
Schedule of Investments [Line Items]        
Amortized Cost, Available-for-sale $ (14,959) [2] $ (6,938)    
Gross Unrealized Holding Gain, Available-for-sale 14,959 [2] 6,938    
Gross Unrealized Holding Loss, Available-for-sale 0 0    
Investment securities available-for-sale $ 0 $ 0    
Total Percent, Available-for-sale 0.00% 0.00%    
[1] Represents Commercial Property Assessed Clean Energy ("C-PACE") bonds.
[2] Represents the amount of portfolio layer method basis adjustments related to AFS MBS securities hedged in a closed portfolio. Under U.S. GAAP, portfolio layer method basis adjustments are not allocated to individual securities, however the amounts impact the unrealized gains or losses for the individual securities being hedged. Refer to Note 3 and Note 10 for additional information.