Investments Summary of Investments (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013	Dec. 31, 2013
Investments [Abstract]
“Available-for-sale” marketable equity securities, cost basis	$ 15,119,000			$ 15,119,000			$ 2,879,000
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax	17,150,000	[1]		17,150,000	[1]		2,177,000
Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax	(1,452,000)			(1,452,000)			(587,000)
“Available-for-sale” marketable equity securities, at fair value	30,817,000			30,817,000			4,469,000
Investments accounted for under cost method	146,760,000			146,760,000			135,819,000
Marketable Securities	177,577,000			177,577,000			140,288,000
Unrealized holding (losses) gains arising during the period	(2,454,000)		(37,000)	13,591,000		323,000
Unrealized Loss in Investment in Privately Held Entities	$ 0			$ 0			$ 0

[1] The increase in our investments during the nine months ended September 30, 2014, includes an increase in unrealized gains of approximately $13.6 million related to our investments in publicly traded life science companies. These unrealized gains are a component of our comprehensive income, within our stockholders’ equity, and have not been recognized in the accompanying consolidated statement of income for the nine months ended September 30, 2014.