Stockholders' Equity (Schedule Of Option Activity) (Details) - $ / shares	6 Months Ended	12 Months Ended
	Dec. 31, 2017	Jun. 30, 2017
Stockholders' Equity [Abstract]
Options, Outstanding at beginning of period	1,495,573
Options, Granted	238,815
Options, Exercised	(362,522)
Options, Forfeited
Options, Outstanding at end of period	1,371,866	1,495,573
Options, Exercise price of granted options	$ 84.98
Options exercisable at end of period	849,755
Weighted Average Exercise Price, Outstanding at beginning of period	$ 47.09
Weighted Average Exercise Price, Granted	84.98
Weighted Average Exercise Price, Exercised	33.34
Weighted Average Exercise Price, Forfeited
Weighted Average Exercise Price, Outstanding at end of period	57.32	$ 47.09
Weighted Average Exercise Price, Options exercisable at end of period	$ 49.14
Weighted Average Remaining Contractual Term in Years, Outstanding	4 years 6 months	3 years 10 months 24 days