Collaborative Arrangements (Details 2) (USD $)	3 Months Ended					3 Months Ended		1 Months Ended	3 Months Ended					3 Months Ended					3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 GSK	Mar. 31, 2013 GSK	Mar. 31, 2014 GSK MABA	Mar. 31, 2014 Long-acting beta agonist (LABA) collaboration GSK Item	Mar. 31, 2013 Long-acting beta agonist (LABA) collaboration GSK	Apr. 30, 2014 Long-acting beta agonist (LABA) collaboration GSK Subsequent events	Mar. 31, 2014 Long-acting beta agonist (LABA) collaboration GSK Minimum	Mar. 31, 2014 Long-acting beta agonist (LABA) collaboration GSK Maximum	Mar. 31, 2014 2004 Strategic alliance GSK MABA Item	Mar. 31, 2013 2004 Strategic alliance GSK MABA	Mar. 31, 2014 2004 Strategic alliance GSK MABA containing '081 Maximum	Mar. 31, 2014 2004 Strategic alliance GSK MABA containing '081 - single-agent	Mar. 31, 2014 2004 Strategic alliance GSK MABA containing '081 - single-agent Minimum	Mar. 31, 2014 2004 Strategic alliance GSK MABA containing '081 - single-agent Maximum	Mar. 31, 2014 2004 Strategic alliance GSK MABA containing '081 - combination product	Mar. 31, 2014 2004 Strategic alliance GSK MABA containing additional MABA Maximum	Mar. 31, 2014 2004 Strategic alliance GSK MABA containing additional MABA - single-agent	Mar. 31, 2014 2004 Strategic alliance GSK MABA containing additional MABA - single-agent Minimum	Mar. 31, 2014 2004 Strategic alliance GSK MABA containing additional MABA - single-agent Maximum	Mar. 31, 2014 Governance agreement GSK Common Stock
Information related to collaborative arrangements
Obligation for milestone payments						$ 220,000,000
Number of combination products						2
Registrational and launch-related milestone fees paid						140,000,000
Registrational and launch-related milestone fees owed								30,000,000
Portion of potential milestone payments that could be payable by the end of 2014						50,000,000
Royalty rate for first level of annual global net sales (as a percent)						15.00%									10.00%	20.00%				10.00%	15.00%
Annual global sales level used to determine royalty rate						3,000,000,000								3,500,000,000					3,500,000,000
Number of products which Company is obligated to use diligent efforts to discover after license of a program											1
Number of preclinical MABA compounds discovered											6
Royalty rate for sales above first level of annual global net sales (as a percent)						5.00%								7.50%					10.00%
Royalty rate for combination products (as a percent)									6.50%	10.00%
Royalty rate for combination products as a percentage of the rate applied to single products																	70.00%		50.00%
Potential contingent payments that the Company could receive																125,000,000
Potential contingent payments that the Company could receive in respect to single-agent and combination medicines													250,000,000
Potential future contingent payments receivable					363,000,000													129,000,000
Company's stock purchased by related party (in shares)																						342,229
Company's stock purchased by related party																						12,900,000
Royalty revenue			730,000	0
Amortization of intangible asset	(1,780,000)	0	(1,780,000)	0
Net royalty revenue	(1,050,000)	0	(1,050,000)	0
Revenues	$ 270,000	$ 1,344,000	$ (780,000)	$ 1,322,000		$ 0	$ 907,000				$ 270,000	$ 415,000