Other Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018
Other Liabilities Disclosure [Abstract]
Accrued bonus and deferred compensation	$ 37,515		$ 36,237
Customer deposits	16,293		11,539
Accrued interest	15,748		12,767
Accrued warranty expense	12,292	$ 12,058	13,388	$ 12,237	$ 12,585	$ 15,331
Litigation accrual	3,570		3,420
Income tax liabilities	1,177		648
Other	24,035		31,430
Total	$ 110,630		$ 109,429