Income Taxes (Tables)

12 Months Ended

Jun. 30, 2013

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	Year ended June 30,
	2013		2012		2011
Current:
Federal	$	54,574	$	48,053	$	43,334
State	4,540		6,022		6,180
Deferred:
Federal	19,553		20,649		18,276
State	4,538		1,960		2,251
	$	83,205	$	76,684	$	70,041

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	June 30,
	2013			2012
Deferred tax assets:
Deferred revenue	$	5,846		$	8,575
Expense reserves (bad debts, insurance, franchise tax and vacation)	12,515			9,349
Net operating loss carryforwards	6,363			9,454
Other, net	1,383			1,410
	26,107			28,788
Deferred tax liabilities:
Accelerated tax depreciation	(35,046		)	(34,636		)
Accelerated tax amortization	(106,147		)	(91,379		)
Prepaid expenses	(25,779		)	(23,331		)
Other, net	(9,714		)	(6,280		)
	(176,686		)	(155,626		)
Net deferred tax liability before valuation allowance	(150,579		)	(126,838		)
Valuation allowance	(700		)	(350		)
Net deferred tax liability	$	(151,279	)	$	(127,188	)

	2013			2012
Deferred income taxes (current)	$	(30,845	)	$	(26,256	)
Deferred income taxes (long-term)	(120,434		)	(100,932		)
	$	(151,279	)	$	(127,188	)

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Year Ended June 30,
	2013		2012		2011
Computed "expected" tax expense	35.0	%	35.0	%	35.0	%
Increase (reduction) in taxes resulting from:
State income taxes, net of federal income tax benefits	2.3	%	2.2	%	2.6	%
Research and development credit	(3.3	)%	(1.8	)%	(2.0	)%
Domestic production activities deduction	(2.2	)%	(2.1	)%	(2.5	)%
Other (net)	0.2	%	(0.2	)%	0.7	%
	32.0	%	33.1	%	33.8	%

Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table Text Block]

	Unrecognized Tax Benefits
Balance at July 1, 2011	$	8,897
Additions for current year tax positions	1,673
Reductions for current year tax positions	—
Additions for prior year tax positions	8
Reductions for prior year tax positions	(2,904		)
Settlements	(1,454		)
Reductions related to expirations of statute of limitations	(18		)
Balance at June 30, 2012	6,202
Additions for current year tax positions	1,087
Reductions for current year tax positions	—
Additions for prior year tax positions	510
Reductions for prior year tax positions	(2,720		)
Settlements	—
Reductions related to expirations of statute of limitations	(189		)
Balance at June 30, 2013	$	4,890