Note 2. Investments and Restricted Cash (Detail) (USD $)	1 Months Ended			6 Months Ended
	Feb. 28, 2011	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011 Unrealized Gains [Member]	Jun. 30, 2011 Unrealized Losses [Member]	Dec. 31, 2010 Short Term Cost Basis [Member]	Jun. 30, 2011 Long Term Cost Basis [Member]
Short-term Investments			$ 1,474,000			$ 800,000
Proceeds from Sale of Short-term Investments	1,400,000
Gain (Loss) on Sale of Investments	600,000
Long-term Investments		4,200,000	1,200,000
Tax Basis of Investments, Cost for Income Tax Purposes		200,000					3,800,000
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax				600,000	200,000
Restricted Cash and Cash Equivalents, Noncurrent		$ 926,000	$ 10,314,000