Income Taxes Computed at Federal Statutory Rate (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income from continuing operations before taxes	$ (71,227)	$ (14,353)	$ 114,279	$ 20,327	$ (32,629)	$ (15,963)	$ 117,316	$ 52,688	$ 49,026	$ 121,412	$ 76,543
Provision for income taxes:
Tax at Federal statutory rate									10,295	25,496	16,074
State taxes net of federal benefit									3,251	7,927	5,224
Permanent differences									249	196	89
Change in valuation allowance									208	86	(113)
Other									(265)	(30)	(649)
Income tax expense									$ 13,738	$ 33,675	$ 20,625