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Organization and Basis of Presentation - Additional Information (Details) |  |  | 9 Months Ended |  |
--- | --- | --- | --- | --- | ---
Jan. 15, 2021 $ / shares | Jan. 08, 2021 | Sep. 30, 2021 | Jan. 07, 2021 $ / shares | Dec. 31, 2020
Common Stock |  |  |  |  |
Organization |  |  |  |  |
Share price (in dollars per share) |  |  |  | $ 58.15 |
Reverse stock split conversion ratio |  | 1.02918 |  |  |
Common Stock | Cash Dividend |  |  |  |  |
Organization |  |  |  |  |
Common stock, dividends, per share, cash paid (in dollars per share) | $ 0.3735 |  |  |  |
Common stock, dividends, per share, stock paid (in dollars per share) | 0.0279 |  |  |  |
Common Stock | Stock Dividend |  |  |  |  |
Organization |  |  |  |  |
Common stock, dividends, per share, stock paid (in dollars per share) | $ 0.0343 |  |  |  |
Service Corporation |  |  |  |  |
Organization |  |  |  |  |
Percentage of ownership in SL Green Management LLC owned by operating partnership (percent) |  |  | 95.00% |  |
Operating Partnership | SL Green Operating Partnership |  |  |  |  |
Organization |  |  |  |  |
Noncontrolling interest in the operating partnership (as a percent) |  |  | 5.50% |  | 5.44%
SL Green Management | SL Green Management LLC |  |  |  |  |
Organization |  |  |  |  |
Percentage of ownership in SL Green Management LLC owned by operating partnership (percent) |  |  | 100.00% |  |

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