Deferred Tax Liability (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Contract and service revenues and costs	$ 54,908	$ 69,597
Expense reserves (bad debts, insurance, franchise tax and vacation)	14,648	14,770
Net operating loss carryforwards	3,547	3,543
Other, net	2,119	2,090
Total gross deferred tax assets	75,222	90,000
Valuation allowance	(357)	(608)
Net deferred tax assets	74,865	89,392
Accelerated tax depreciation	(36,994)	(40,857)
Accelerated tax amortization	(178,999)	(160,719)
Contract and service revenues and costs	(78,413)	(76,417)
Total gross deferred liabilities	294,406	277,993
Net deferred tax liability	$ (219,541)	$ (188,601)