Supplemental Disclosure of Cash Flow Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Cash paid during the period for:
Income taxes, net	$ 2,238	$ 11,116
Interest	1,566	6,233
Non-cash investing activities:
Acquisition of NYC heating oil customer list		886
Non-cash operating activities:
Increase in interest expense-amortization of debt discount on 8.875% Senior Notes and amortization of deferred charges on senior secured term loan	$ 71	$ 30