Components of Deferred Income Taxes (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Deferred tax liabilities:
Intangibles	$ 388	$ 398
Unrealized currency gain	10,892	7,330
Total deferred tax liabilities	11,280	7,728
Deferred tax assets:
Net operating loss carryforwards	166,951	96,997
Federal and state tax credit carryovers	28,645	19,654
Depreciation	3,607	4,785
Stock-based compensation	7,780	5,491
Other	7,977	3,703
Total deferred tax assets	214,960	130,630
Deferred tax assets, net	203,680	122,902
Valuation allowance	(203,680)	(122,902)
Total deferred taxes