Note 6 - Stock-based Compensation (Details) (USD $) | 3 Months Ended | | |
In Millions, except Share data, unless otherwise specified | Mar. 31, 2015 | Mar. 31, 2014 | Dec. 31, 2014 | Dec. 31, 2013 |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | 274,746 | 274,746 | 274,746 | 274,746 |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value (in Dollars) | 3.3 | | | |
Restricted Stock [Member] | Director [Member] | Common Class A [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 58,191 | 41,881 | | |
Restricted Stock [Member] | Common Class A [Member] | Employee [Member] | January 31, 2016 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | 76,442 | | | |
Restricted Stock [Member] | Common Class A [Member] | Employee [Member] | January 31, 2017 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | 76,442 | | | |
Restricted Stock [Member] | Common Class A [Member] | Employee [Member] | January 31, 2018 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | 76,438 | | | |
Restricted Stock [Member] | Common Class A [Member] | Employee [Member] | January 17, 2015 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | | 75,412 | | |
Restricted Stock [Member] | Common Class A [Member] | Employee [Member] | January 17, 2016 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | | 43,590 | | |
Restricted Stock [Member] | Common Class A [Member] | Employee [Member] | January 17, 2017 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | | 43,590 | | |
Restricted Stock [Member] | Common Class A [Member] | Employee [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 229,322 | 194,413 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | | 31,821 | | |
Restricted Stock [Member] | Common Class A [Member] | Director [Member] | January 31, 2016 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | 58,191 | | | |
Restricted Stock [Member] | Common Class A [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 287,513 | 236,294 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | 117,293 | 31,821 | | |
Restricted Stock [Member] | 2007 Incentive Plan [Member] | Employee [Member] | January 31, 2016 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | 50,102 | | | |
Restricted Stock [Member] | 2007 Incentive Plan [Member] | Employee [Member] | January 31, 2017 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | 50,100 | | | |
Restricted Stock [Member] | 2007 Incentive Plan [Member] | Employee [Member] | January 31, 2018 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | 50,106 | | | |
Restricted Stock [Member] | 2007 Incentive Plan [Member] | Employee [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 150,308 | | | |
Restricted Stock [Member] | Directors' Restricted Stock Plan [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 0 | 0 | | |
Restricted Stock [Member] | Employee [Member] | January 17, 2015 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | | 127,316 | | |
Restricted Stock [Member] | Employee [Member] | January 17, 2016 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | | 58,327 | | |
Restricted Stock [Member] | Employee [Member] | January 17, 2017 [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number | | 58,327 | | |
Restricted Stock [Member] | Employee [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | | 312,961 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | | 68,991 | | |
Restricted Stock [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 150,308 | 312,961 | | |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period | 197,858 | 202,743 | | |
Common Class A [Member] | | | | |
Note 6 - Stock-based Compensation (Details) [Line Items] | | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number | 0 | | | |