Consolidated Statements of Changes in Equity (Parentheticals) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Treasury Stock repurchased, shares	71,506	34,759	44,077
Class A Common Stock [Member]
Stock issued for stock compensation, shares	458,565	266,452	472,982
Common Stock [Member] | Class A Common Stock [Member]
Stock issued during period, shares	4,000,000
Settlement of deferred stock awards, shares	78,088
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	35,000	227,347	588,504
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