Note 2. Cash, Investments, and Restricted Cash (Detail) (USD $)	1 Months Ended		3 Months Ended	12 Months Ended
	Feb. 28, 2011	Jan. 31, 2010	Dec. 31, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Short-term Investments					$ 1,474,000
Cost Basis Of Short Term Investments					800,000
Proceeds from Sale of Short-term Investments	1,400,000
Gain (Loss) on Sale of Investments	600,000	500,000
Long-term Investments			3,923,000	3,923,000	1,194,000
Tax Basis of Investments, Cost for Income Tax Purposes		600,000	3,500,000	3,500,000	200,000
Other than Temporary Impairment Losses, Investments			100,000	140,000	739,000	3,018,000
Proceeds from Sale, Maturity and Collection of Investments		1,100,000
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax			835,000	835,000	1,462,000	744,000	(2,122,000)
Restricted Investments			900,000	900,000	10,300,000
Non-Current Investments Held Having Net Gain Position [Member]
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax			400,000	400,000
Non-Current Investments Held Having Net Loss Position [Member]
Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax			$ 47,000	$ 47,000