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SUBSEQUENT EVENTS (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands |  |  |  | 3 Months Ended | 9 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Oct. 24, 2024 | Oct. 21, 2024 | Jun. 09, 2020 | Sep. 30, 2024 | Jun. 30, 2024 | Mar. 31, 2024 | Sep. 30, 2023 | Jun. 30, 2023 | Mar. 31, 2023 | Sep. 30, 2024 | Sep. 30, 2023 | Dec. 31, 2023
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Dividends on common stock (in dollars per share) |  |  |  | $ 0.32 | $ 0.32 | $ 0.32 | $ 0.30 | $ 0.30 | $ 0.30 | $ 0.96 | $ 0.90 |
Dividends on preferred stock (in dollars per share) |  |  |  | 171.88 | $ 171.88 | $ 171.88 | $ 171.88 | $ 171.88 | $ 171.88 |  |  |
Common stock, par value (in dollars per share) |  |  |  | $ 1.33 |  |  |  |  |  | $ 1.33 |  | $ 1.33
Proceeds from issuance of common stock |  |  |  |  |  |  |  |  |  | $ 227 | $ 563 |
Subsequent Event [Member] | Sandy Spring [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Common stock, par value (in dollars per share) |  | $ 1.00 |  |  |  |  |  |  |  |  |  |
Stock conversion, par value (in dollars per share) |  | $ 1.33 |  |  |  |  |  |  |  |  |  |
Conversion ratio |  | 0.90% |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] | Sandy Spring [Member] | Morgan Stanley & Co. LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Shares issued and sold |  | 9,859,155 |  |  |  |  |  |  |  |  |  |
Proceeds from sale of common stock, settlement period |  | 18 months |  |  |  |  |  |  |  |  |  |
Proceeds from issuance of common stock |  | $ 386,400 |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] | Sandy Spring [Member] | Underwriter |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Shares issued and sold |  | 1,478,873 |  |  |  |  |  |  |  |  |  |
Underwriter granted option period |  | 30 days |  |  |  |  |  |  |  |  |  |
Number of stocks option, granted |  | 1,478,873 |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] | Maximum [Member] | Sandy Spring [Member] | Morgan Stanley & Co. LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Sale of price per share |  | $ 35.50 |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] | Minimum [Member] | Sandy Spring [Member] | Morgan Stanley & Co. LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Sale of price per share |  | $ 34.08 |  |  |  |  |  |  |  |  |  |
O 2024 Q4 Preferred Dividends [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Dividends payable, date declared | Oct. 24, 2024 |  |  |  |  |  |  |  |  |  |  |
Common Class A [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Dividends on common stock (in dollars per share) | $ 0.34 |  |  |  |  |  |  |  |  |  |  |
Common Class A [Member] | O 2024 Q4 Common Dividends [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Dividends payable, date to be paid | Nov. 22, 2024 |  |  |  |  |  |  |  |  |  |  |
Dividends payable, date of record | Nov. 08, 2024 |  |  |  |  |  |  |  |  |  |  |
Depositary Shares |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Shares issued and sold |  |  | 6,900,000 |  |  |  |  |  |  |  |  |
Depositary Shares | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Dividends on preferred stock (in dollars per share) | $ 0.43 |  |  |  |  |  |  |  |  |  |  |
Series A Preferred Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of preferred stock represented by each depositary share |  |  | each representing a 1/400th ownership interest in a share of its Series A preferred stock |  |  |  |  |  |  |  |  |
Series A Preferred Stock [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of preferred stock represented by each depositary share | each representing a 1/400th ownership interest in a share of Series A preferred stock |  |  |  |  |  |  |  |  |  |  |
Dividends on preferred stock (in dollars per share) | $ 171.88 |  |  |  |  |  |  |  |  |  |  |
Series A Preferred Stock [Member] | O 2024 Q4 Preferred Dividends [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Dividends payable, date to be paid | Dec. 02, 2024 |  |  |  |  |  |  |  |  |  |  |
Dividends payable, date of record | Nov. 15, 2024 |  |  |  |  |  |  |  |  |  |  |

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