Note 4 - Share-based Compensation (Details Textual) - USD ($)
$ / shares in Units, $ in Millions |
3 Months Ended |
Sep. 30, 2016 |
Sep. 30, 2015 |
| Restricted Stock Units (RSUs) [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period |
65,000
|
35,000
|
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |
$ 109.36
|
$ 105.01
|
| Restricted Stock [Member] |
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period |
17,000
|
12,000
|
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |
$ 106.59
|
$ 108.49
|
| Selling, General and Administrative Expenses [Member] |
|
|
| Allocated Share-based Compensation Expense |
$ 3.2
|
$ 2.0
|
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross |
1,000,000
|
736,000
|
| Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price |
$ 107.60
|
$ 106.66
|
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value |
$ 17.98
|
$ 18.48
|
| Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized |
$ 35.2
|
|
| Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition |
2 years 328 days
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period |
22,000
|
12,500
|
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value |
$ 0.9
|
$ 0.5
|