Income Taxes - Schedule of Reconciliation of Statutory Federal Income Taxes to Effective Taxes (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Tax at statutory federal rate	$ (25,001)	$ (134,702)	$ (86,333)
State tax, net of federal benefit	178	(12,580)	(8,118)
Nondeductible expenses	733	9,897	10,742
Foreign income rate differential	(253)	262	(56)
U.S. tax credits	(6,682)	(2,785)	(5,049)
Other reconciling items	1,317	525	1,589
Change in valuation allowance	32,296	139,519	87,714
Provision for income taxes	$ 2,588	$ 136	$ 489