Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Contingencies And Commitments [Line Items]
Royalty expense	$ 4,100,000	$ 2,900,000	$ 1,800,000
Purchase commitments related to contract manufacturing, clinical development and certain other items	12,600,000
Litigation settlement payment description	August 1, 2007, between us (and our subsidiaries) and Bayer Healthcare LLC, as amended, related to the inhaled amikacin program in exchange for (i) a $5.0 million payment due on April 1, 2014; (ii) a $5.0 million payment due on January 1, 2015, (iii) a series of four $500,000 payments each due on April 1, 2014, January 1, 2015, January 1, 2016, and January 1, 2017, respectively; and (iv) certain other terms and conditions.
Total litigation settlement payments	12,000,000
Discount rate	8.00%
Securities Related Claims [Member]
Contingencies And Commitments [Line Items]
Obligations under Director and Officer Indemnifications per incident	1,000,000
Non-securities Related Claims [Member]
Contingencies And Commitments [Line Items]
Obligations under Director and Officer Indemnifications per incident	500,000
Indemnification Agreement [Member]
Contingencies And Commitments [Line Items]
Indemnification Obligations, liabilities	0	0
Research and development expense [Member]
Contingencies And Commitments [Line Items]
Present value of settlement payments	11,300,000
Other Current Liabilities [Member]
Contingencies And Commitments [Line Items]
Current portion of settlement liability	5,500,000
April 1, 2014 [Member]
Contingencies And Commitments [Line Items]
Settlement installment payment due	5,000,000
Settlement installment series payment due	500,000
January 1, 2015 [Member]
Contingencies And Commitments [Line Items]
Settlement installment payment due	5,000,000
Settlement installment series payment due	500,000
January 1, 2016 [Member]
Contingencies And Commitments [Line Items]
Settlement installment series payment due	500,000
January 1, 2017 [Member]
Contingencies And Commitments [Line Items]
Settlement installment series payment due	$ 500,000