Merger with Nuvelo, Inc. on January 27, 2009 (Details) (USD $)	1 Months Ended	135 Months Ended
	Jan. 27, 2009	Mar. 31, 2013
Merger with Nuvelo, Inc. On January 27, 2009 (Textual) [Abstract]
Estimated total acquisition consideration	$ 11,900,000
Net assets acquired in the Merger	37,200,000
Net assets acquired, including cash, cash equivalents and marketable securities	45,500,000
Gain on bargain purchase	$ 25,300,000	$ 25,282,000