Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid‑in Capital	Retained Deficit	Accumulated Other Comprehensive (Loss) Income	Noncontrolling Interest	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjustment Retained Deficit
Common stock issued at the beginning of the period (shares) at Sep. 30, 2018		115,016,000
Stockholders' equity, balance at the beginning of the period at Sep. 30, 2018	$ 362,016	$ 1,145	$ (2,837)	$ 533,435	$ (163,871)	$ (9,017)	$ 3,161	$ (1,582)	$ (1,582)
Treasury stock, balance at the beginning of the period (shares) at Sep. 30, 2018			1,087,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity based compensation expense	19,903			19,903
Issuance of common stock (shares)		108,000
Shares withheld related to net share settlement (including tax withholdings)		$ 0
Shares of common stock issued in initial public offering, net of offering costs	363			363
Dividends paid to non‑controlling interest	(1,150)						(1,150)
Net income (loss)	(8,471)				(9,523)		1,052
Shares withheld related to net share settlement (including tax withholdings) (shares)		884,000	577,000
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net	(1,270)	$ 9		(1,279)
Common stock issued at the end of the period (shares) at Sep. 30, 2019		116,008,000
Stockholders' equity, balance at the end of the period at Sep. 30, 2019	365,822	$ 1,154	$ (2,837)	552,422	(174,976)	(13,004)	3,063		$ (1,337)
Treasury stock, balance at the end of the period (shares) at Sep. 30, 2019			1,664,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	(3,987)
Equity based compensation expense	10,509			10,509
Issuance of common stock (shares)		3,478,000	531,000
Shares withheld related to net share settlement (including tax withholdings)	18,927	$ 35		18,892
Dividends paid to non‑controlling interest	(1,890)						(1,890)
Net income (loss)	$ 114,395				113,649		746
Common stock issued at the end of the period (shares) at Sep. 30, 2020	119,486,000	119,486,000
Stockholders' equity, balance at the end of the period at Sep. 30, 2020	$ 482,063	$ 1,189	$ (2,837)	564,928	(62,664)	(20,472)	1,919
Treasury stock, balance at the end of the period (shares) at Sep. 30, 2020	2,195,000		2,195,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	$ (7,468)
Divestiture of Lange product line	(16,895)
Equity based compensation expense	15,524			15,524
Issuance of common stock (shares)		2,687,000	(531,000)
Shares withheld related to net share settlement (including tax withholdings)	1,634	$ 34		1,600
Dividends paid to non‑controlling interest	(551)						(551)
Net income (loss)	$ 51,662				51,482
Common stock issued at the end of the period (shares) at Sep. 30, 2021	122,173,000	122,173,000
Stockholders' equity, balance at the end of the period at Sep. 30, 2021	$ 582,219	$ 1,223	$ (2,837)	$ 582,052	$ (11,182)	$ 11,415	$ 1,548
Treasury stock, balance at the end of the period (shares) at Sep. 30, 2021	1,664,000		1,664,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax	$ 31,887