Income Taxes - Variation Between Expected and Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Statutory federal income tax (benefit) rate (percent)	(35.00%)	35.00%	35.00%
State income taxes (net of federal benefit) (percent)	(1.30%)	0.90%	2.00%
Qualified domestic production activities (percent)	0.50%	(2.30%)	(8.90%)
Research and development tax credits (percent)	(2.90%)	(11.30%)	(48.90%)
Goodwill impairment (percent)	6.70%	0.00%	0.00%
Increase in valuation allowance (percent)	0.60%	8.50%	0.90%
Non deductible book expenses (percent)	0.20%	0.90%	1.80%
Changes in deferred tax assets (percent)	0.10%	(5.00%)	(1.50%)
Remeasurement of deferred taxes for changes in state tax law (percent)	0.00%	(1.90%)	0.00%
Changes in tax reserves (percent)	0.10%	(0.70%)	(0.50%)
Other (percent)	(0.20%)	0.20%	(1.10%)
Effective income tax (benefit) rate (percent)	(31.20%)	24.30%	(21.20%)