Detail of Certain Balance Sheet Accounts - AP (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016
Accounts Payable and Accrued Liabilities [Abstract]
Accounts Payable, Trade	$ 63,246	$ 64,963
Accrued Employee Benefits	33,561	26,827
Accrued Insurance	6,204	5,464
Other Accrued Liabilities	17,699	11,568
Accounts Payable and Accrued Liabilities, Current, Total	$ 120,710	$ 108,822