Other Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017
Other Liabilities Disclosure [Abstract]
Accrued bonus and deferred compensation	$ 27,069		$ 41,508
Accrued interest	23,913		14,401
Customer deposits	19,681		14,903
Accrued warranty expense	12,237	$ 12,585	15,331	$ 15,290	$ 14,583	$ 18,091
Litigation accrual	3,209		3,656
Income tax liabilities	632		710
Other	30,894		35,880
Total	$ 117,635		$ 126,389