Deferred Tax Liability (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Contract and service revenues	$ 13,450	$ 0
Expense reserves (bad debts, insurance, franchise tax and vacation)	14,325	11,164
Net operating loss carryforwards	2,713	2,759
Other, net	851	2,711
Total gross deferred tax assets	31,339	16,634
Valuation allowance	(415)	(515)
Net deferred tax assets	30,924	16,119
Accelerated tax depreciation	(31,846)	(32,026)
Accelerated tax amortization	(154,633)	(141,274)
Contract and service revenues	0	(5,067)
Contract and service costs	(61,455)	(46,055)
Total gross deferred liabilities	247,934	224,422
Net deferred tax liability	$ (217,010)	$ (208,303)