Mundipharma Agreements - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended				6 Months Ended		1 Months Ended	3 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Sep. 05, 2012	Jun. 30, 2013 Maximum [Member] Regulatory [Member]	Jun. 30, 2013 Maximum [Member] Commercial progress- and sales-dependent [Member]	May 29, 2013 Mundipharma [Member]	Jun. 30, 2013 Mundipharma [Member]	Jun. 30, 2013 Mundipharma [Member]	May 31, 2013 Mundipharma [Member]	Jun. 30, 2013 Mundipharma [Member] Reimbursed joint development cost [Member]	Jun. 30, 2013 Mundipharma [Member] Reimbursed joint development cost [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments							$ 16,000,000	$ 107,000,000
Deferred development cost						12,300,000
Company determined development payment	43,770,000	46,140,000	87,248,000	82,896,000					7,000,000
Development cost liability										18,700,000	18,700,000
Development cost differential, maximum payment													15,000,000	15,000,000
License and contract revenue	10,501,000	9,583,000	22,482,000	18,474,000									268,000	589,000
Portion of joint development costs incurred by the parties										40.00%
Potential portion of joint development costs incurred by the parties											50.00%
Developmental cost differential amount												12,099
Remaining developmental cost										18,700,000	18,700,000
Fair value of related contingent payment obligation to research and development									0
Difference in related contingent payment					2,287,000				2,400,000
Accounts receivable										$ 24,000	$ 24,000