Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Jul. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Increased (decreased) in valuation allowance tax		$ (8,600,000)	$ 18,900,000
Net operating loss carryforwards, federal		76,000,000
Net operating loss carryforwards, state		$ 231,400,000
Net tax operating losses, expiration		Begin to expire in 2032 in various amounts if not utilized.
Reduction in expected deductibility of certain executive compensation due to application of new limitations		$ 600,000
Reduction in net federal and state deferred tax assets due to reduction in corporate tax rate		13,500,000
Unrecognized tax benefits		30,051,000	9,285,000	$ 4,314,000	$ 1,643,000
Unrecognized tax benefits if recognized would impact effective tax rate		100,000
Cash tax impact of license of intellectual property rights between consolidated entities	$ 0
Increase in unrecognized tax benefits		800,000	$ 400,000
Licensed Intellectual Property Rights
Income Taxes [Line Items]
Expected uncertain tax benefits during next 12 months		800,000
Federal and State | ASU 2016-09
Income Taxes [Line Items]
Net operating losses		$ 10,500,000