Net Earnings (Loss) Per Common Share Computation of Basic and Diluted Net Earnings (Loss) Per Common Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Basic
Average common shares outstanding	31,877	31,873	31,838	31,999
Net earnings (loss)	$ 2,864	$ 12,800	$ 9,120	$ 30,915
Net earnings (loss) per common share	$ 0.09	$ 0.40	$ 0.29	$ 0.97
Diluted
Average common shares outstanding	31,877	31,873	31,838	31,999
Shares related to convertible debt	0	251	0	382
Stock options and awards	24	67	9	330
Average common shares assuming dilution	31,901	32,191	31,847	32,711
Net Earnings (loss)	$ 2,864	$ 12,800	$ 9,120	$ 30,915
Net Earnings (loss) per Share - Assuming Dilution	$ 0.09	$ 0.40	$ 0.29	$ 0.95