Consolidated Balance Sheets Parenthetical (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Allowance for doubtful accounts	$ 7,764	$ 7,299
Common, stated value $20.00 per share	$ 20.00	$ 20.00
Authorized	20,000,000	20,000,000
Issued to voting trustees	10,611,982	9,498,347
Issued to shareholders	2,285,255	2,148,384
In treasury, at cost	(15,725)	(26,755)
Outstanding Common Stock	12,881,512	11,619,976
Common shares subscribed	610,949	565,844
Less subscriptons receivable	(610,949)	(565,844)