Investment in Regulus Therapeutics Inc. (Details 2) (USD $)			1 Months Ended			1 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Oct. 31, 2010 Regulus	Dec. 31, 2011 Regulus	Dec. 31, 2011 Regulus Convertible notes guarantee obligation	Oct. 31, 2010 Regulus Sanofi	Oct. 31, 2010 Regulus Sanofi Less than
Equity method of accounting
Equity investments						$ 10,000,000
Equity ownership (as a percent)							10.00%
Gain on equity method accounting			4,700,000
Principal plus accrued interest					5,500,000
Carrying value of investment	$ (4,424,000)	$ (870,000)		$ (4,400,000)