Consolidated Statements of Shareholders' Equity (Parentheticals) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Common Class A [Member] \| Common Stock [Member]
Shares of treasure stock purchased	65,131	11,445	324,093
Shares of common stock issued for the excercise of stock options	140,595	155,253	786,303
Issuance of restricted shares, net of forfeitures	50,038		10,074
Dividends declared per common share (in Dollars per share)	$ 0.06	$ 0.05	$ 0.42
Common Class A [Member]
Shares of common stock issued for the excercise of stock options	140,595
Common Class B [Member] \| Common Stock [Member]
Shares of treasure stock purchased	4,317	1,908	54,015
Shares of common stock issued for the excercise of stock options	23,432	31,876	131,051
Issuance of restricted shares, net of forfeitures	8,340		1,679
Dividends declared per common share (in Dollars per share)	$ 0.36	$ 0.31	$ 2.54
Common Class B [Member]
Shares of common stock issued for the excercise of stock options	23,432

Aggregate dividends paid during the period for each share of common stock outstanding.

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Number of share options (or share units) exercised during the current period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

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Number of shares that have been repurchased during the period and are being held in treasury.

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