EARNINGS PER SHARE - Discontinuing Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Basic net income per share:
Net income									$ 20,885	$ 191,175	$ 22,156
Less: Net income attributable to non-controlling interests									$ 6,639	$ 66,980	$ 6,351
Weighted average shares of Class A common stock outstanding - basic (in shares)									23,911,250	23,419,421	23,137,586
Basic net income per share (in USD per share)	$ 0.08	$ 0.55	$ (0.05)	$ 0.01	$ 4.71	$ 0.18	$ 0.17	$ 0.20	$ 0.60	$ 5.30	$ 0.68
Dilutive net income per share:
Reallocation of net income assuming conversion of common units									$ 6,586	$ 46,978	$ (1,391)
Weighted average shares of Class A common stock outstanding - basic (in shares)									23,911,250	23,419,421	23,137,586
Weighted average effect of dilutive securities (in shares)									10,274,434	10,459,742	10,109,247
Diluted for continuing and discontinued operations (in shares) diluted (in shares)									34,185,684	33,879,163	33,246,833
Diluted net income per share (in USD per share)	$ 0.07	$ 0.55	$ (0.05)	$ 0.01	$ 4.61	$ 0.18	$ 0.17	$ 0.20	$ 0.56	$ 5.30	$ 0.68
Discontinued Operations
Dilutive net income per share:
Diluted for continuing and discontinued operations (in shares) diluted (in shares)										23,419,421	23,137,586
Class A Common Stock | Discontinued Operations
Basic net income per share:
Net income									$ 20,885	$ 191,175	$ 22,156
Less: Net income attributable to non-controlling interests									6,639	66,980	6,351
Net income attributable to Class A common stockholders									$ 14,246	$ 124,195	$ 15,805
Weighted average shares of Class A common stock outstanding - basic (in shares)									23,911,250	23,419,421	23,137,586
Basic net income per share (in USD per share)									$ 0.60	$ 5.30	$ 0.68
Dilutive net income per share:
Net income attributable to Class A common stockholders									$ 14,246	$ 124,195	$ 15,805
Reallocation of net income assuming conversion of common units									5,066
Net income attributable to Class A common stockholders - diluted									$ 19,312
Weighted average shares of Class A common stock outstanding - basic (in shares)									23,911,250	23,419,421	23,137,586
Weighted average effect of dilutive securities (in shares)									10,274,434
Diluted for continuing and discontinued operations (in shares) diluted (in shares)									34,185,684
Diluted net income per share (in USD per share)									$ 0.56