Unaudited Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Common Class A
Common stock, par value	$ 1	$ 1	$ 1
Common stock, shares outstanding	6,046,238	6,290,414	6,454,764
Common Class B
Common stock, par value	$ 1	$ 1	$ 1
Common stock, convertible conversion ratio	1	1	1
Common stock, shares outstanding	1,580,590	1,581,106	1,581,835