Note 13 - Employee Stock Option and Retirement Plans (Details Textual) - USD ($) | Aug. 31, 2014 | Dec. 23, 2013 | Jul. 31, 2012 | Nov. 30, 2015 | Aug. 31, 2015 | Feb. 28, 2015 | Nov. 30, 2014 | Aug. 31, 2013 | Aug. 31, 2017 |
Employee Stock Option [Member] | The 2004 Stock Option and Award Plan [Member] | Minimum [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period | | | | 7 years | | | | | |
Employee Stock Option [Member] | The 2004 Stock Option and Award Plan [Member] | Maximum [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period | | | | 10 years | | | | | |
Employee Stock Option [Member] | The 2004 Stock Option and Award Plan [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | | | | 5 years | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | | | | 1,044,203 | | | | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | | | | $ 170.21 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | | | | 3,875,703 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price | | | | $ 122.06 | | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | | | | $ 57,900,000 | | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | | | | 3 years 328 days | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number | | | | 1,200,000 | 1,400,000 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price | | | | $ 83.59 | $ 78.70 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value | | | | $ 102,300,000 | $ 107,100,000 | | | | |
Employee Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | | | | $ 170.21 | | | $ 131.31 | | |
Performance Shares [Member] | Share-based Compensation Award, Tranche One [Member] | Code Red, Inc. [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | | | | | | 2 years | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | | | | | | 68,761 | | | |
Performance Shares [Member] | Share-based Compensation Award, Tranche One [Member] | Portware LLC [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | 40.00% | | | | | |
Performance Shares [Member] | Share-based Compensation Award, Tranche One [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | | | | 20.00% | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares | | | | | | | | 48,314 | |
Performance Shares [Member] | Share-based Compensation Award, Tranche Two [Member] | Code Red, Inc. [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | | | | | | 4 years | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | | | | | | 68,761 | | | |
Performance Shares [Member] | Share-based Compensation Award, Tranche Two [Member] | Portware LLC [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | 20.00% | | | | | |
Performance Shares [Member] | Share-based Compensation Award, Tranche Two [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | 20.00% | | | | | | | | |
Performance Shares [Member] | Share-based Compensation Award, Tranche Three [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | 20.00% | | | | |
Performance Shares [Member] | Share-based Compensation Award, Tranche Four [Member] | Scenario, Forecast [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | | | | | | 20.00% |
Performance Shares [Member] | Code Red, Inc. [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | | | | | | 4 years | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | | | | | | 137,522 | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | | | | $ 1,900,000 | | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | | | | 3 years 73 days | | | | | |
Performance Shares [Member] | Portware LLC [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | | | | 530,418 | | | | | |
Performance Shares [Member] | Matrix Data Limited [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | | 165,949 | | | | | | | |
Stock Granted, Value, Share-based Compensation, Gross | | $ 5,000,000 | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Measurement Period | | 5 years | | | | | | | |
Performance Shares [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross | | | 241,546 | 530,418 | | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | | | | $ 500,000 | | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | | | | 1 year 255 days | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | 20.00% | | | | | | |
Restricted Stock [Member] | The 2004 Stock Option and Award Plan [Member] | Share-based Compensation Award, Tranche One [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | | | | 40.00% | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Measurement Period | | | | 5 years | | | | | |
Restricted Stock [Member] | The 2004 Stock Option and Award Plan [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | | | | 4 years 328 days | | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | | | | $ 33,100,000 | | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | | | | 3 years 292 days | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | | 93,120 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | | | | $ 159.46 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | | | | 368,486 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | | | | 37,079 | | | | | |
Restricted Stock [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | | 93,120 | | | 10,225 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value | | | | $ 159.46 | | | $ 127.58 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number | | | | 368,000 | 313,000 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | | | | 37,079 | | | 53,495 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Share Equivalent | | | | 2.5 | | | | | |
The 2004 Stock Option and Award Plan [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value | | | | $ 27,700,000 | | | $ 6,000,000 | | |
The 2008 Employee Stock Purchase Plan [Member] | | | | | | | | | |
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price | | | | $ 130.36 | | | $ 108.68 | | |
Stock Issued During Period, Shares, Employee Stock Purchase Plans | | | | 15,835 | | | 15,397 | | |
Treasury Stock Acquired, Average Cost Per Share | | | | $ 130.36 | | | $ 108.68 | | |
Common Stock, Capital Shares Reserved for Future Issuance | | | | 465,781 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | | | | 3,876,000 | 3,117,000 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price | | | | $ 122.06 | $ 100.71 | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized | | | | $ 91,000,000 | | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | | | | 3 years 328 days | | | | | |
Share Price | | | | $ 169.53 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent | | | | 85.00% | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Rate | | | | 10.00% | | | | | |
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent | | | | 60.00% | | | | | |
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay | | | | 4.00% | | | | | |
Defined Contribution Plan, Employer Matching Contribution, Vesting Period | | | | 5 years | | | | | |
Defined Contribution Plan, Employer Discretionary Contribution Amount | | | | $ 2,000,000 | | | $ 1,800,000 | | |