Income Taxes - Income Tax Provision Related to Continuing Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
U.S. federal provision (benefit)
At statutory rate	$ (55,919)	$ (60,007)	$ (46,536)
State taxes	50	(48)	1
Change in valuation allowance	55,042	47,349	48,959
Foreign tax inclusion		6,510
Non-cash interest expense on liability related to sale of future royalties	7,808	6,320
Foreign tax differential	(20)	(227)	(129)
Research credits	(6,273)	(591)	(893)
Other	1,557	1,100	(384)
Provision for income taxes	$ 2,245	$ 406	$ 1,018