Note 8 - Earnings Per Share (Details) - Calculation of Earnings Per Share (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Employee Stock Option [Member] \| Common Class A [Member]
Weighted average effect of dilutive securities:
Weighted average effect of dilutive securities	379	526	369	537
Employee Stock Option [Member] \| Common Class B [Member]
Weighted average effect of dilutive securities:
Weighted average effect of dilutive securities	65	87	62	89
Restricted Stock [Member] \| Common Class A [Member]
Weighted average effect of dilutive securities:
Weighted average effect of dilutive securities	34	49	34	49
Restricted Stock [Member] \| Common Class B [Member]
Weighted average effect of dilutive securities:
Weighted average effect of dilutive securities	6	8	6	8
Common Class A [Member]
Numerator for net income per share - basic:
Allocation of distributed earnings (in Dollars)		$ 882	$ 1,071	$ 1,762
Allocation of undistributed earnings (in Dollars)	1,717	1,088	2,881	2,132
Net income attributable to common shareholders (in Dollars)	1,717	1,970	3,952	3,894
Denominator for net income per share - basic:
Weighted average common shares outstanding - basic	20,672	20,254	20,671	20,206
Weighted average effect of dilutive securities:
Weighted average common shares outstanding - diluted	21,085	20,829	21,074	20,792
Net income per share - diluted (in Dollars per share)	$ 0.08	$ 0.09	$ 0.19	$ 0.19
Net income per share - basic (in Dollars per share)	$ 0.08	$ 0.10	$ 0.19	$ 0.19
Numerator for net income per share - diluted:
Net income attributable to common shareholders for basic computation (in Dollars)	1,717	1,970	3,952	3,894
Common Class B [Member]
Numerator for net income per share - basic:
Allocation of distributed earnings (in Dollars)		882	1,071	1,762
Allocation of undistributed earnings (in Dollars)	1,717	1,088	2,881	2,132
Net income attributable to common shareholders (in Dollars)	1,717	1,970	3,952	3,894
Denominator for net income per share - basic:
Weighted average common shares outstanding - basic	3,445	3,376	3,445	3,368
Weighted average effect of dilutive securities:
Weighted average common shares outstanding - diluted	3,516	3,471	3,513	3,465
Net income per share - diluted (in Dollars per share)	$ 0.49	$ 0.57	$ 1.12	$ 1.12
Net income per share - basic (in Dollars per share)	$ 0.50	$ 0.58	$ 1.15	$ 1.16
Numerator for net income per share - diluted:
Net income attributable to common shareholders for basic computation (in Dollars)	$ 1,717	$ 1,970	$ 3,952	$ 3,894

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The total amount of dividends declared in the period for each class of stock and the contractual amount of dividends (or interest on participating income bonds) that must be paid for the period (for example, unpaid cumulative dividends). Dividends declared in the current period do not include dividends declared in respect of prior-period unpaid cumulative dividends. Preferred dividends that are cumulative only if earned are deducted only to the extent that they are earned.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Earnings allocated (not distributed) to participating securities under the two-class method to the extent that participating securities may share in earnings as if all of the earnings for the period had been distributed.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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This element represents the weighted average total number of shares issued throughout the period including the first (beginning balance outstanding) and last (ending balance outstanding) day of the period before considering any reductions (for instance, shares held in treasury) to arrive at the weighted average number of shares outstanding. Weighted average relates to the portion of time within a reporting period that common shares have been issued and outstanding to the total time in that period. Such concept is used in determining the weighted average number of shares outstanding for purposes of calculating earnings per share (basic).

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