Interim Financial Statements (Details) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Relistor [Abstract]
Number of countries approved sale of Relistor	50
Receipt of upfront cash under license agreement	$ 60,000,000
Receipt of upfront ex-U.S. sublicensee revenue	200,000
Eligible to receive
License fee receivable on U.S. Marketing approval for subcutaneous Relistor, maximum	40,000,000
License fee receivable on U.S. Marketing approval for oral formulation of Relistor, maximum	50,000,000
Payment receivable on achievement of specified U.S. sales targets	200,000,000
Percentage of royalties, minimum (in hundredths)	15.00%
Percentage of royalties, maximum (in hundredths)	19.00%
Percentage of upfront, milestone, reimbursement or other revenue (in hundredths)	60.00%
Annual U.S. sales, minimum	100,000,000
Funding and Financial Matters [Abstract]
Cash and cash equivalents at end of period	47,820,000	82,405,000
Decrease in cash and cash equivalents	(22,285,000)	34,487,000
Cash and cash equivalents at beginning of period	70,105,000	47,918,000
Minimum number of years cash will fund operations (in years)	1 year
Authorized amount of common shares under stock repurchase program, maximum	15,000,000
Remaining authorized amount of common shares under stock repurchase program	12,300,000
Stock repurchased during the period, value	$ 0