Acquisition (Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Jan. 09, 2017	Nov. 01, 2016	Mar. 31, 2017	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015
Business Acquisition [Line Items]
Goodwill			$ 129,921	$ 109,448	$ 110,707	$ 100,183
SMART Temps
Business Acquisition [Line Items]
Cash	$ 28,754
Fair value of contingent consideration on acquired business	10
Total purchase price consideration	28,764
Fair value of net tangible assets acquired	897
Goodwill	18,556
Total assets acquired and liabilities assumed	28,764
FreshTemp
Business Acquisition [Line Items]
Cash		$ 1,697
Purchase price payable upon completion of diligence matters		303
Fair value of contingent consideration on acquired business		1,300
Working capital adjustment		(37)
Total purchase price consideration		3,263
Fair value of net tangible assets acquired		(37)
Goodwill		2,650
Total assets acquired and liabilities assumed		3,263
Purchased and Core Technology | SMART Temps
Business Acquisition [Line Items]
Fair value of identifiable intangible assets acquired	4,000
Purchased and Core Technology | FreshTemp
Business Acquisition [Line Items]
Fair value of identifiable intangible assets acquired		400
Customer Relationships | SMART Temps
Business Acquisition [Line Items]
Fair value of identifiable intangible assets acquired	4,000
Customer Relationships | FreshTemp
Business Acquisition [Line Items]
Fair value of identifiable intangible assets acquired		$ 250
Trademarks and Trade Names | SMART Temps
Business Acquisition [Line Items]
Fair value of identifiable intangible assets acquired	711
Noncompete Agreements | SMART Temps
Business Acquisition [Line Items]
Fair value of identifiable intangible assets acquired	$ 600