Significant Accounting Policies - Additional Information (Detail)			1 Months Ended			3 Months Ended			6 Months Ended	12 Months Ended
	Jul. 16, 2018 $ / shares shares	Dec. 26, 2017 $ / shares	Jul. 31, 2018 USD ($)	Feb. 28, 2018 USD ($)	Dec. 31, 2017 USD ($) $ / shares shares	Mar. 31, 2019 USD ($) Segment shares	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018 shares	May 31, 2016 shares	Dec. 31, 2015 USD ($)
Significant Accounting Policies [Line Items]
License payment term for product goods and service						1 year
Payment by licensees and transfer of promised goods or services to licensees will be one year or less						true
Common stock, shares issued | shares						139,000,000						126,485,000
Increase (decrease) in the fair value of warrant liability						$ (8,815,000)		$ 1,465,000
Reserve for settlement of fines					$ 17,100,000									$ 4,000,000
Estimated insurance recoveries					15,000,000
Restricted cash balances						0
Transfers of financial assets from Level 1 to Level 2						0
Transfers of financial assets from Level 2 to Level 1						0
Tax benefits of the stock based compensation expenses recognized						0		0
Short-term operating lease obligations recognized						$ 200,000
United States
Significant Accounting Policies [Line Items]
Number of operating segments | Segment						1
Non-US
Significant Accounting Policies [Line Items]
Net assets located outside of the United States						$ 0
Scenario Forecast
Significant Accounting Policies [Line Items]
Effective tax rate										0.00%
Minimum
Significant Accounting Policies [Line Items]
Marketable securities maturity term						3 months
Maximum
Significant Accounting Policies [Line Items]
Marketable securities maturity term						24 months
Term of lease obligations											12 months
PIPE Warrants
Significant Accounting Policies [Line Items]
Warrant liability						$ 9,300,000
Increase (decrease) in the fair value of warrant liability						$ (8,800,000)		1,500,000
Reduction in warrant liability in connection with warrant exercises								1,100,000
PIPE Warrants | Private Placement
Significant Accounting Policies [Line Items]
Common stock, shares issued | shares													17,642,482
Warrants exercisable shares of common stock exercised | shares						803,108
Cash proceeds						$ 800,000
Warrants exercisable shares of common stock outstanding | shares						16,839,375
Settlement Warrants
Significant Accounting Policies [Line Items]
Increase (decrease) in the fair value of warrant liability							$ (700,000)	$ 42,000	$ (700,000)
Reserve for settlement of fines					17,100,000
Estimated insurance recoveries					15,000,000	$ 15,000,000
Estimated fair value of warrants			$ 1,400,000		$ 2,100,000
Warrants to purchase of common stock shares | shares	2,000,000				2,000,000
Warrants exercisable expiration period	1 year	1 year			1 year
Warrants exercise price | $ / shares	$ 3.00	$ 3.00			$ 3.00
Cash settlement from insurance carriers				$ 15,000,000
Reclassified of settlement warrants from a liability to stockholders equity			$ 1,400,000