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Equity Based Compensation - Compensation Expense (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Equity based compensation |  |  |
Equity based compensation expense | $ 31,606 | $ 19,654 | $ 13,529
AM LTIP RSUs |  |  |
Equity based compensation |  |  |
Equity based compensation expense | 24,409 | 16,039 | 11,461
ROIC PSUs |  |  |
Equity based compensation |  |  |
Equity based compensation expense | 6,266 | 2,770 | 1,158
Equity awards issued to directors |  |  |
Equity based compensation |  |  |
Equity based compensation expense | $ 931 | $ 845 | $ 910

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