Components of Deferred Tax Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Net operating losses	$ 246,500	$ 236,500
Research and development credits	27,700	25,600
Capitalized research and development	34,500	21,000
Share-based compensation expense	5,200	4,900
Deferred revenue	800	2,000
Deferred gain on sales leaseback	8,500	9,800
Intangibles	13,200	15,800
Cease-use expense	1,300	1,500
Fixed assets	300	200
Other	3,700	3,900
Total deferred tax assets	341,700	321,200
Valuation allowance	(341,700)	(321,200)
Net deferred tax assets	$ 0	$ 0