Short-term Investments (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 8,427,000
Unrealized Gain (Loss) on Investments	1,830,000
Short-term Investments	$ 6,597,000	$ 0