Other Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Other Liabilities Disclosure [Abstract]
Accrued interest	$ 24,653	$ 11,024
Accrued bonus and deferred compensation	16,638	36,753
Accrued warranty expense	15,816	18,091	$ 32,309	$ 39,131
Customer deposits	13,837	11,704
Litigation accrual	3,970	3,899
Income tax liabilities	1,033	811
Other	27,210	25,377
Total other liabilities	$ 103,157	$ 107,659