| Summary of Provision for Income Taxes | A summary of the provision for income taxes was as follows:   
|   |   | Year Ended December 31, |   |  
|   |   | 2021 |   |   | 2020 |   |   | 2019 |   |  
|   |   | (in thousands) |   |  
| Current expense: |   |   |   |   |   |   |   |   |   |   |   |   |  
| Federal |   | $ | 21,805 |   |   | $ | 10,565 |   |   | $ | 18,737 |   |  
| State |   |   | 10,901 |   |   |   | 6,310 |   |   |   | 9,377 |   |  
| Total current expense |   |   | 32,706 |   |   |   | 16,875 |   |   |   | 28,114 |   |  
| Deferred expense (benefit): |   |   |   |   |   |   |   |   |   |   |   |   |  
| Federal |   | $ | 4,914 |   |   |   | 663 |   |   |   | (10,515 | ) |  
| State |   |   | (803 | ) |   |   | (239 | ) |   |   | (3,039 | ) |  
| Total deferred expense |   |   | 4,111 |   |   |   | 424 |   |   |   | (13,554 | ) |  
| Income tax expense |   | $ | 36,817 |   |   | $ | 17,299 |   |   | $ | 14,560 |   |  | 
| Summary of Deferred Tax Assets and Liabilities | Deferred tax assets and liabilities were as follows:   
|   |   | Year Ended December 31, |   |  
|   |   | 2021 |   |   | 2020 |   |   | 2019 |   |  
|   |   | (in thousands) |   |  
| Deferred tax assets: |   |   |   |   |   |   |   |   |   |   |   |   |  
| Provision for credit losses |   | $ | 21,671 |   |   | $ | 26,883 |   |   | $ | 18,401 |   |  
| Purchase accounting |   |   | 3,360 |   |   |   | 3,902 |   |   |   | 3,912 |   |  
| Net operating loss carryforward |   |   | 15,316 |   |   |   | 15,342 |   |   |   | 15,453 |   |  
| Unrealized loss on securities available for sale |   |   | 3,421 |   |   |   | — |   |   |   | — |   |  
| Mark to market |   |   | — |   |   |   | — |   |   |   | 261 |   |  
| Lease liability |   |   | 14,712 |   |   |   | 15,562 |   |   |   | 10,716 |   |  
| Tax credits |   |   | — |   |   |   | — |   |   |   | 198 |   |  
| State taxes |   |   | 2,318 |   |   |   | 1,223 |   |   |   | 1,739 |   |  
| Other |   |   | 4,032 |   |   |   | 3,669 |   |   |   | 3,766 |   |  
| Total deferred tax assets |   |   | 64,830 |   |   |   | 66,581 |   |   |   | 54,446 |   |  
| Deferred tax liabilities: |   |   |   |   |   |   |   |   |   |   |   |   |  
| Mark to market |   |   | (3,531 | ) |   |   | (1,660 | ) |   |   | — |   |  
| Depreciation |   |   | (1,292 | ) |   |   | (631 | ) |   |   | (388 | ) |  
| Unrealized gain loss on securities available for sale |   |   | — |   |   |   | (1,247 | ) |   |   | (1,370 | ) |  
| Leases - right of use assets |   |   | (13,738 | ) |   |   | (15,044 | ) |   |   | (10,517 | ) |  
| Other |   |   | (2,650 | ) |   |   | (2,228 | ) |   |   | (532 | ) |  
| Total deferred tax liabilities |   |   | (21,211 | ) |   |   | (20,810 | ) |   |   | (12,807 | ) |  
| Valuation allowance |   |   | (1,644 | ) |   |   | (4,352 | ) |   |   | (4,852 | ) |  
| Net deferred tax assets |   | $ | 41,975 |   |   | $ | 41,418 |   |   | $ | 36,787 |   |  |