Income Tax - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Valuation allowance increase	$ 22,500	$ 21,500
Deferred tax assets	62,277	$ 39,757
State Administration of Taxation, China [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	1,300
Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	133,000
Federal [Member] | Research and development Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carry forward	3,300
State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	132,600
State [Member] | Research and development Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carry forward	2,300
Federal and State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards related to excess tax deductions for stock compensation	2,300
Change in ownership, as defined in Section 382 [Member]
Operating Loss Carryforwards [Line Items]
Deferred tax assets	23,500
Change in ownership, as defined in Section 382 [Member] | Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	58,700
Change in ownership, as defined in Section 382 [Member] | Federal [Member] | Research and development Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carry forward	2,200
Change in ownership, as defined in Section 382 [Member] | State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	51,100
Change in ownership, as defined in Section 382 [Member] | State [Member] | Research and development Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carry forward	$ 1,600