Intangible Assets by Major Class Subject to Amortization (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Jun. 30, 2014	Sep. 30, 2013
Finite-Lived Intangible Assets [Line Items]
Original Cost	$ 20,523	$ 20,523
Accumulated Amortization	8,507	6,872
Net Book Value	12,016	13,651
Trade name
Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)	10 years	10 years
Original Cost	2,000	2,000
Accumulated Amortization	596	446
Net Book Value	1,404	1,554
Non-compete agreement
Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)	5 years	5 years
Original Cost	1,600	1,600
Accumulated Amortization	908	668
Net Book Value	692	932
Below market lease
Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)	5 years	5 years
Original Cost	900	900
Accumulated Amortization	640	505
Net Book Value	260	395
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)	10 years	10 years
Original Cost	13,800	13,800
Accumulated Amortization	4,146	3,111
Net Book Value	9,654	10,689
Order backlog
Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)	1 year	1 year
Original Cost	2,200	2,200
Accumulated Amortization	2,194	2,119
Net Book Value	6	81
Transition services
Finite-Lived Intangible Assets [Line Items]
Original Cost	23	23
Accumulated Amortization	23	23
Net Book Value	$ 0	$ 0
Maximum | Transition services
Finite-Lived Intangible Assets [Line Items]
Estimated useful life (in years)	1 year	1 year