Unaudited Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2011	Dec. 31, 2010
Common Class A [Member]
Common stock, par value	$ 1	$ 1
Common stock, shares outstanding	6,800,615	6,737,199
Common Class B [Member]
Common stock, par value	$ 1	$ 1
Common stock, shares outstanding	1,595,781	1,596,093