Consolidated Statements Of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Consolidated Statements Of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$ 36,435	$ 9,746	$ (9,330)
Other comprehensive income (loss):
Unrealized loss on marketable securities			242
Effect of income taxes			(85)
Accumulated income (loss)	(1,756)	(1,001)	1,569
Effect of income taxes	644	350	(548)
Prior service cost	60	60	60
Effect of income taxes	(22)	(21)	(21)
Other comprehensive income (loss)	(1,074)	(612)	1,217
Comprehensive income (loss)	$ 35,361	$ 9,134	$ (8,113)