Investments (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012	Dec. 31, 2008	Aug. 31, 2007
Unrealized gain (loss) on investment under fair value method	$ 1,100,000	$ 3,600,000
Percentage of discount on cash flows due to high degree of risk	55.00%
Intelliject [Member]
Total cash invested in private company				7,500,000	7,500,000
Ownership interest percentage	20.00%
Carrying value	34,800,000		33,700,000
Unrealized gain (loss) on investment under fair value method	1,100,000	3,600,000
Weighted average cost of capital	55.00%		55.00%
Basis point decrease of weighted average cost of capital assumption	500
Basis point increase of weighted average cost of capital assumption	500
Increase in fair value from five hundred point decrease in weighted average cost of capital assumption	6,000,000
Decrease in fair value from five hundred point increase in weighted average cost of capital assumption	5,000,000
Harbinger Fund [Member]
Carrying value of investment	3,400,000		3,600,000
Cost-method investment, OTTI		1,100,000
Cost-method investment, OTTI net of tax		700,000
Total withdrawal proceeds received	$ 200,000	$ 0