Supporting Financial Information - Goodwill and Intangible Asset Adjustment (Details) $ in Thousands	6 Months Ended
	Mar. 31, 2017 USD ($)
Goodwill [Roll Forward]
Goodwill, Gross Period Start	$ 34,745
Goodwill, Measurement Period Adjustment	(8,756)
Goodwill, Gross Period End	25,989
Goodwill and Finite Lived Intangible Assets Total [Roll Forward]
Goodwill and Finite-Lived Intangible Assets, Gross Period Start	43,362
Goodwill Purchase Accounting Adjustment and Finite-Lived Intangible Asset Measurement Period Adjustment	250
Goodwill and Finite-Lived Intangible Assets, Gross Period End	43,612
Customer Relationships [Member]
Indefinite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Gross, Period Start	7,247
Finite-Lived Intangible Assets, Measurement Period Adjustment	9,379
Finite-Lived Intangible Assets, Gross, Period End	16,626
Noncompete Agreements [Member]
Indefinite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Gross, Period Start	1,370
Finite-Lived Intangible Assets, Measurement Period Adjustment	(890)
Finite-Lived Intangible Assets, Gross, Period End	480
Trade Names [Member]
Indefinite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Gross, Period Start	0
Finite-Lived Intangible Assets, Measurement Period Adjustment	517
Finite-Lived Intangible Assets, Gross, Period End	$ 517