Investments in Non-Publicly Traded Companies (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Additional Investments	$ 0.1	$ 0.1
Neurone II [Member]
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest	3.00%
Munich Venture Partners Fund [Member]
Subsidiary of Limited Liability Company or Limited Partnership, Ownership Interest	0.42%