| SECURITIES (Gross Realized Gains and Losses on the Sale of Securities) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
| Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020 | |
| Securities [Abstract] | ||||
| Gross realized gains | $ 0 | $ 10,339 | $ 138 | $ 12,503 | 
| Gross realized losses | 0 | 0 | (60) | (228) | 
| Gains on securities transactions, net | 0 | 10,339 | 78 | 12,275 | 
| Proceeds from sales of securities | $ 0 | $ 107,570 | $ 45,436 | $ 228,271 | 
| X | ||||||||||
| 
- Definition Amount of realized gain (loss) on investment in debt and equity securities. No definition available. 
 | 
| X | ||||||||||
| 
- Definition Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
 | 
| X | ||||||||||
| 
- Definition Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
 | 
| X | ||||||||||
| 
- References No definition available. 
 | 
| X | ||||||||||
| 
- Definition Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
 |