Consolidated Statements of Changes in Equity (Parentheticals) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Treasury Stock repurchased, shares	34,759	44,077	12,666
Class A Common Stock [Member]
Stock issued for stock compensation, shares	266,542	472,982	600,949
Common Stock [Member] | Class A Common Stock [Member]
Settlement of deferred stock awards, shares			4,859
Common Stock [Member] | Class A Common Stock [Member] | Conversion of Class B Common Stock to Class A Common Stock [Member]
Conversion of shares to Class A Common Stock, shares	227,347	588,504	119,963
Common Stock [Member] | Class A Common Stock [Member] | Series A-1 Preferred Stock to Class A Common Stock [Member]
Conversion of shares to Class A Common Stock, shares			5,984,232
Common Stock [Member] | Class A Common Stock [Member] | Common stock and TEUs [Member]
Conversion of shares to Class A Common Stock, shares	3,539,240