v3.21.1
Debt Securities - Available for Sale Securities in Continuous Loss Position (Details)
$ in Thousands
Mar. 31, 2021
USD ($)
security
Dec. 31, 2020
USD ($)
security
Schedule of Available-for-sale Securities    
Number of Securities | security 203 57
Less than 12 months, fair value $ 830,852 $ 200,831
Less than 12 months, unrealized losses 17,376 895
12 Months or more, fair value 10,328 7,376
12 Months or more, unrealized loss 450 419
Fair Value 841,180 208,207
Unrealized Losses $ 17,826 $ 1,314
State and political subdivisions    
Schedule of Available-for-sale Securities    
Number of Securities | security 145 27
Less than 12 months, fair value $ 274,770 $ 31,489
Less than 12 months, unrealized losses 7,413 157
12 Months or more, fair value 9,468 4,065
12 Months or more, unrealized loss 294 326
Fair Value 284,238 35,554
Unrealized Losses $ 7,707 $ 483
Mortgage-backed securities    
Schedule of Available-for-sale Securities    
Number of Securities | security 8 7
Less than 12 months, fair value $ 20,218 $ 315
Less than 12 months, unrealized losses 743 1
12 Months or more, fair value 110 0
12 Months or more, unrealized loss 1 0
Fair Value 20,328 315
Unrealized Losses $ 744 $ 1
Collateralized mortgage obligations    
Schedule of Available-for-sale Securities    
Number of Securities | security 22 8
Less than 12 months, fair value $ 392,272 $ 133,032
Less than 12 months, unrealized losses 5,677 214
12 Months or more, fair value 0 0
12 Months or more, unrealized loss 0 0
Fair Value 392,272 133,032
Unrealized Losses $ 5,677 $ 214
Corporate debt securities    
Schedule of Available-for-sale Securities    
Number of Securities | security 28 15
Less than 12 months, fair value $ 143,592 $ 35,995
Less than 12 months, unrealized losses 3,543 523
12 Months or more, fair value 750 3,311
12 Months or more, unrealized loss 155 93
Fair Value 144,342 39,306
Unrealized Losses $ 3,698 $ 616