Cash And Cash Equivalents, Short-Term Investments, Long-Term Investments And Other Investments (The Company's Capital Commitments) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2011
Remaining Commitment	$ 800
Bay City Capital Fund IV, L.P. [Member]
Ownership	2.90%
Total Capital Commitment	10,000
Remaining Commitment	705
Commitment Expiration	September  2010	[1]
Bay City Capital Fund V, L.P. [Member]
Ownership	2.00%
Total Capital Commitment	10,000
Remaining Commitment	5,552
Commitment Expiration	October 2012
A.M. Pappas Life Science Ventures III, L.P. [Member]
Ownership	4.70%
Total Capital Commitment	4,750
Remaining Commitment	594
Commitment Expiration	December  2009	[1]
A.M. Pappas Life Science Ventures IV, L.P. [Member]
Ownership	3.00%
Total Capital Commitment	2,935
Remaining Commitment	1,702
Commitment Expiration	February 2014
Accelerator III And Incubator Companies [Member]
Ownership	19.90%	[2]
Total Capital Commitment	4,802	[2]
Remaining Commitment	$ 819	[2]
Commitment Expiration	None	[2]
Accelerator III And Incubator Companies [Member] | Maximum [Member]
Maximum ownership percentage	19.90%

[1] The funding commitments to Bay City Capital Fund IV, L.P. and A.M. Pappas Life Science Ventures III, L.P. have expired for new investments. The Company may still be required to fund additional investments in existing fund portfolio companies and the ongoing operations of these funds up to the amount of the remaining capital commitment.

[2] The Company's percentage ownership of Accelerator III and incubator companies might vary but will not exceed 19.9%.