Financing Arrangements (Senior Notes Payable) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Debt Instrument [Line Items]
Total borrowings under Senior Secured Credit Facility	$ 215,389	$ 255,551
Less: current portion	(29,764)	(58,676)
Total long-term portion of borrowings under Senior Secured Credit Facility	185,625	196,875
Total borrowings under Equipment Financing Facilities	246,355
Less current portion	(35,116)
Total long-term portion of borrowings under Equipment Financing Facilities	211,239
Canadian Revolver
Debt Instrument [Line Items]
Total borrowings under Senior Secured Credit Facility	10,714	2,426
US Revolver
Debt Instrument [Line Items]
Total borrowings under Senior Secured Credit Facility	7,800	45,000
Term Loan
Debt Instrument [Line Items]
Total borrowings under Senior Secured Credit Facility	196,875	208,125
Equipment Financing Facilities
Debt Instrument [Line Items]
Total borrowings under Equipment Financing Facilities	30,966	10,597
Less current portion	(5,352)	(3,848)
Total long-term portion of borrowings under Equipment Financing Facilities	$ 25,614	$ 6,749