Intangible Assets by Major Class Subject to Amortization (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Mar. 31, 2013	Sep. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Original Cost	$ 19,400	$ 19,400
Accumulated Amortization	5,825	4,773
Net Book Value	13,575	14,627
Trade name
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	10 years	10 years
Original Cost	1,900	1,900
Accumulated Amortization	349	254
Net Book Value	1,551	1,646
Non-compete agreement
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	5 years	5 years
Original Cost	1,500	1,500
Accumulated Amortization	514	364
Net Book Value	986	1,136
Below market lease
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	5 years	5 years
Original Cost	900	900
Accumulated Amortization	415	325
Net Book Value	485	575
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	10 years	10 years
Original Cost	13,000	13,000
Accumulated Amortization	2,447	1,796
Net Book Value	10,553	11,204
Order backlog
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	1 year	1 year
Original Cost	2,100	2,100
Accumulated Amortization	2,100	2,034
Net Book Value	$ 0	$ 66