Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheets
Accounts receivable - trade, allowance (in dollars)	$ 1,138	$ 865
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	41,977,725	41,576,869
Common stock, shares outstanding	41,977,725	41,576,869