Acquisitions (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2015 USD ($) item	Sep. 30, 2014 USD ($) item	Sep. 30, 2013 USD ($) item
Aggregate assets acquired:
Goodwill	$ 24,384	$ 23,622	$ 15,821
Goodwill expected to be deductible for tax purposes	$ 762	$ 7,801	$ 1,069
Trademarks, tradenames, customer relationships and non-compete agreement | Minimum
Aggregate assets acquired:
Amortization period	2 years
Trademarks, tradenames, customer relationships and non-compete agreement | Maximum
Aggregate assets acquired:
Amortization period	15 years
Acquisitions
ACQUISITIONS
Number of business acquisitions | item	2	7	4
Aggregate purchase price in cash	$ 1,266	$ 16,377	$ 3,382
Aggregate assets acquired:
Current assets	111	2,773	794
Goodwill	762	7,801	1,069
Intangible assets	393	5,803	1,519
Aggregate purchase price	1,266	16,377	3,382
Acquired intangible assets expected to be deductible for tax purposes	$ 393	$ 5,803	$ 1,519
Expected period for deduction of acquired intangible assets for tax purposes	15 years
Expected period for deduction of acquired goodwill for tax purposes	15 years