Nature of Business and Summary of Significant Accounting Policies - Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jun. 30, 2018
Intangible Assets by Major Class [Line Items]
Finite-lived intangible assets, Cost	$ 15,700	$ 15,700
Finite-lived intangible assets, Accumulated amortization	(8,468)	(8,155)
Finite-lived intangible assets, Net book value	7,232	7,545
Customer relationships [Member]
Intangible Assets by Major Class [Line Items]
Finite-lived intangible assets, Cost	9,800	9,800
Finite-lived intangible assets, Accumulated amortization	(8,468)	(8,155)
Finite-lived intangible assets, Net book value	1,332	1,645
Trade name [Member]
Intangible Assets by Major Class [Line Items]
Finite-lived intangible assets, Cost	5,900	5,900
Finite-lived intangible assets, Net book value	$ 5,900	$ 5,900