Note 9 - Equity-based Compensation (Details Textual) - USD ($) | Aug. 04, 2015 | Jun. 30, 2016 | Jun. 30, 2015 | Jun. 30, 2016 | Jun. 30, 2015 | Jun. 30, 2106 | Dec. 31, 2015 | Jun. 05, 2015 |
Maximum [Member] | The 2015 Plan [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | | | | | | | | 600,000 |
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Authorized for Incentive Stock Options | | | | | | | | 400,000 |
The 2015 Plan [Member] | Restricted Stock Units (RSUs) [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | | | | 3 years | | | | |
Restricted Stock Units (RSUs) [Member] | Non-employee Directors [Member | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Vested and Deferred, Number | | 2,192 | | 2,192 | | | | |
Restricted Stock Units (RSUs) [Member] | | | | | | | | |
Annual Retainer | | $ 150,000 | | $ 150,000 | | | | |
Additional Annual Retainer | | $ 15,000 | | $ 15,000 | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | 2,379 | | | | | | |
Stock Granted, Value, Share-based Compensation, Gross | | $ 1,100,000 | | | | | | |
Restricted Stock [Member] | Graham Holding Company [Member] | Spinoff [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number | | | 10,830 | | 10,830 | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Accelerated Vesting, Number | | | 6,324 | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Forfeitures | | | 4,506 | | | | | |
Restricted Stock [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | 726 | | | | | | |
Stock Granted, Value, Share-based Compensation, Gross | | $ 300,000 | | | | | | |
Restricted Stock and Restricted Stock Units [Member] | Employees and Non-employee Directors [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | | 9,350 | | | | |
Stock Granted, Value, Share-based Compensation, Gross | | | | $ 4,100,000 | | | | |
Restricted Stock and Restricted Stock Units [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | | 9,350 | | | | |
Allocated Share-based Compensation Expense | | 2,700,000 | | $ 5,000,000 | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options | | 12,800,000 | | $ 12,800,000 | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | | | | 1 year 109 days | | | | |
Stock Appreciation Rights (SARs) [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period | 4 years | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | | | 2,500 | | | | |
Allocated Share-based Compensation Expense | | 800,000 | | $ 1,500,000 | | | | |
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options | | $ 9,600,000 | | $ 9,600,000 | | | | |
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, Non-Option Equity Instruments, Outstanding, Number | | 138,100 | | 138,100 | | | 135,600 | |
Specific Employees [Member] | Graham Holding Company [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | | 0 | 750 | 0 | 750 | | | |
Selling, General and Administrative Expenses [Member] | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost | | | $ 3,700,000 | | $ 3,700,000 | | | |
Allocated Share-based Compensation Expense | | $ 3,400,000 | $ 4,000,000 | $ 6,500,000 | $ 4,300,000 | | | |
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense | | | | $ 1,300,000 | | | | |
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost | | | | | | $ 4,200,000 | | |