Consolidated Balance Sheets (Parentheticals) (USD $)	Dec. 31, 2012	Dec. 31, 2011
Class A [Member]
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	180,000,000	180,000,000
Common Stock, Shares, Issued	57,882,442	52,717,553
Common Stock, Shares, Outstanding	45,359,083	40,257,656
Treasury Stock, Shares	12,523,359	12,459,897
Class B [Member]
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	30,000,000	30,000,000
Common Stock, Shares, Issued	1,728,952	2,192,473
Common Stock, Shares, Outstanding	1,728,952	2,192,473