Quarterly Financial Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2017
REVENUE
REVENUE	$ 393,509	$ 380,364	$ 386,275	$ 392,543	$ 378,256	$ 374,048	$ 357,209	$ 361,284	$ 1,552,691	$ 1,470,797	$ 1,388,290
EXPENSES
Cost of Revenue	240,040	235,594	227,284	220,112	223,606	218,517	207,100	203,915	923,030	853,138	805,855
Research and Development	24,920	23,442	23,990	24,026	24,406	22,591	22,414	20,929	96,378	90,340	84,753
Selling, General and Administrative	49,131	44,887	46,797	45,183	45,294	42,234	43,094	41,088	185,998	171,710	159,235
Gain on Disposal of Businesses					0	0	(189)	(1,705)	0	(1,894)	(3,270)
Total Expenses	314,091	303,923	298,071	289,321	293,306	283,342	272,419	264,227	1,205,406	1,113,294	1,046,573
OPERATING INCOME	79,418	76,441	88,204	103,222	84,950	90,706	84,790	97,057	347,285	357,503	341,717
INTEREST INCOME (EXPENSE)
Interest Income	178	155	252	291	152	130	146	147	876	575	248
Interest Expense	(407)	(224)	(148)	(147)	(747)	(734)	(250)	(189)	(926)	(1,920)	(996)
Total Interest Income (Expense)	(229)	(69)	104	144	(595)	(604)	(104)	(42)	(50)	(1,345)	(748)
INCOME BEFORE INCOME TAXES	79,189	76,372	88,308	103,366	84,355	90,102	84,686	97,015	347,235	356,158	340,969
PROVISION/ (BENEFIT) FOR INCOME TAXES	18,196	17,120	20,219	19,815	16,519	21,017	(76,557)	30,145	75,350	(8,876)	111,408
NET INCOME	$ 60,993	$ 59,252	$ 68,089	$ 83,551	$ 67,836	$ 69,085	$ 161,243	$ 66,870	$ 271,885	$ 365,034	$ 229,561
Basic earnings per share	$ 0.79	$ 0.77	$ 0.88	$ 1.08	$ 0.88	$ 0.89	$ 2.09	$ 0.87	$ 3.52	$ 4.73	$ 2.95
Basic weighted average shares outstanding	77,060	77,177	77,216	77,188	77,261	77,247	77,218	77,283	77,160	77,252	77,856
Diluted earnings per share	$ 0.79	$ 0.77	$ 0.88	$ 1.08	$ 0.87	$ 0.89	$ 2.08	$ 0.86	$ 3.52	$ 4.70	$ 2.93
Diluted weighted average shares outstanding	77,157	77,286	77,409	77,537	77,585	77,546	77,565	77,646	77,347	77,585	78,255