XML 58 R47.htm IDEA: XBRL DOCUMENT v3.21.2
Investment Securities - Amortized Cost and Estimated Fair Value (Details) - USD ($)
$ in Thousands
Sep. 30, 2021
Jul. 01, 2021
Dec. 31, 2020
Investment securities available-for-sale:      
Amortized  Cost $ 4,705,112   $ 3,846,733
Gross Unrealized Gain 47,186   90,004
Gross Unrealized Loss (42,483)   (5,622)
Estimated Fair Value 4,709,815   3,931,115
Investment securities held-to-maturity:      
Amortized  Cost 170,587   23,732
Allowance for Credit Losses (11)   0
Net Carrying Amount 170,576   23,732
Gross Unrecognized Gain 803   1,281
Gross Unrecognized Loss (2,225)   0
Estimated Fair Value 169,154   25,013
U.S. Treasury      
Investment securities available-for-sale:      
Amortized  Cost 77,803   30,153
Gross Unrealized Gain 1,665   2,380
Gross Unrealized Loss (126)   0
Estimated Fair Value 79,342   32,533
Agency      
Investment securities available-for-sale:      
Amortized  Cost 531,867   666,702
Gross Unrealized Gain 5,252   24,292
Gross Unrealized Loss (7,026)   (608)
Estimated Fair Value 530,093   690,386
Corporate      
Investment securities available-for-sale:      
Amortized  Cost 383,910   412,223
Gross Unrealized Gain 5,381   3,591
Gross Unrealized Loss (2,900)   (506)
Estimated Fair Value 386,391   415,308
Municipal bonds      
Investment securities available-for-sale:      
Amortized  Cost 1,237,923   1,412,012
Gross Unrealized Gain 27,585   37,260
Gross Unrealized Loss (9,642)   (3,253)
Estimated Fair Value 1,255,866   1,446,019
Investment securities held-to-maturity:      
Amortized  Cost 154,399    
Allowance for Credit Losses (11)    
Net Carrying Amount 154,388    
Gross Unrecognized Gain 0    
Gross Unrecognized Loss (2,225) $ (3,200)  
Estimated Fair Value 152,163    
Collateralized mortgage obligations      
Investment securities available-for-sale:      
Amortized  Cost 665,851   513,259
Gross Unrealized Gain 1,109   819
Gross Unrealized Loss (4,729)   (712)
Estimated Fair Value 662,231   513,366
Mortgage-backed securities      
Investment securities available-for-sale:      
Amortized  Cost 1,807,758   812,384
Gross Unrealized Gain 6,194   21,662
Gross Unrealized Loss (18,060)   (543)
Estimated Fair Value 1,795,892   833,503
Investment securities held-to-maturity:      
Amortized  Cost 14,656   22,124
Allowance for Credit Losses 0   0
Net Carrying Amount 14,656   22,124
Gross Unrecognized Gain 803   1,281
Gross Unrecognized Loss 0   0
Estimated Fair Value 15,459   23,405
Other      
Investment securities held-to-maturity:      
Amortized  Cost 1,532   1,608
Allowance for Credit Losses 0   0
Net Carrying Amount 1,532   1,608
Gross Unrecognized Gain 0   0
Gross Unrecognized Loss 0   0
Estimated Fair Value $ 1,532   $ 1,608