Common and Preferred Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended						3 Months Ended	12 Months Ended
	Oct. 09, 2020	Jun. 24, 2020	Mar. 31, 2021	Feb. 28, 2021	Jan. 31, 2021	Dec. 31, 2020	Jun. 30, 2020	Feb. 28, 2018	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Oct. 31, 2021	Aug. 31, 2019
Class of Stock [Line Items]
Common stock, shares authorized						400,000,000			400,000,000	400,000,000	400,000,000
Common stock, par value						$ 0.01			$ 0.01	$ 0.01	$ 0.01
Undesignated preferred stock, shares authorized						10,000,000			10,000,000	10,000,000	10,000,000
Undesignated preferred stock, par value						$ 0.01			$ 0.01	$ 0.01	$ 0.01
Common stock, shares issued						242,117,089			242,117,089	251,477,562	242,117,089
Common stock, shares outstanding						242,117,089			242,117,089	251,477,562	242,117,089
Undesignated preferred stock, shares outstanding						0			0	0	0
Debt issuance amount			$ 230,000
Proceeds from market price stock purchase plan										$ 106	$ 215
Market price stock purchase plan										25,000
MidCap Credit Facility
Class of Stock [Line Items]
Common stock, shares issued												964,113
Class of Warrant or Right, Number of Securities Called by Warrants or Rights												1,283,467
QrumPharma
Class of Stock [Line Items]
Number of common stock issued						3,067,179
MidCap Credit Facility
Class of Stock [Line Items]
Warrants to purchase of common stock						111,853			111,853		111,853
Warrants expiration date						Dec. 01, 2027			Dec. 01, 2027		Dec. 01, 2027
Underwriting Agreement
Class of Stock [Line Items]
Number of shares sold during the period							26,666,667
Class of Warrant or Right, Number of Securities Called by Warrants or Rights							7,250,000
Exercise price of warrants							$ 1.60
Issuance of common stock in at-the-market offering/placement (in shares)							26,666,667
Class of Warrant or Right, Outstanding							26,666,667
Remaining Warrants Available for Purchase							0
Convertible Promissory Note | The Mann Group L L C
Class of Stock [Line Items]
Conversion of debt shares issued					4,000,000.0				2,800,000	4,000,000,000,000	2,800,000
Conversion of notes accrued interest to common shares, value					$ 400				$ 3,000
Conversion of notes accrued interest to common shares									1,200,000
Debt issuance amount					$ 9,600				$ 7,000	$ 9,600	$ 7,000
2024 Convertible Notes
Class of Stock [Line Items]
Conversion of debt shares issued				1,666,667
Debt issuance amount				$ 5,000
Tranche 1 | MidCap Credit Facility
Class of Stock [Line Items]
Exercise price of warrants													$ 1.11
Warrants to purchase of common stock												1,171,614	1,171,614
Tranche 2 | MidCap Credit Facility
Class of Stock [Line Items]
Exercise price of warrants						$ 2.91			$ 2.91		$ 2.91
Warrants to purchase of common stock						111,853			111,853		111,853	111,853
Common Stock | June 2020 Note
Class of Stock [Line Items]
Conversion of debt shares issued		1,235,094
Common Stock | December 2020 Note
Class of Stock [Line Items]
Conversion of debt shares issued	1,377,356
Contolled Equity Offering Sales Agreement | Cantor Fitzgerald
Class of Stock [Line Items]
Stock purchase agreements date								Feb. 28, 2018
Contolled Equity Offering Sales Agreement | Cantor Fitzgerald | Common Stock | Maximum
Class of Stock [Line Items]
Amount of net proceeds from issuance of securities								$ 50,000
At Market Issuance Sales Agreement | Cantor Fitzgerald | Common Stock
Class of Stock [Line Items]
Amount of net proceeds from issuance of securities										$ 1,900	$ 23,500
Number of shares sold during the period										578,063	11,851,566
Exchange price per share						$ 1.99			$ 1.99	$ 3.26	$ 1.99
Issuance of common stock in at-the-market offering/placement (in shares)										578,063	11,851,566