Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Public Offering Of Common Stock And Warrants 2019	Common Stock	Common Stock Public Offering Of Common Stock And Warrants 2019	Treasury Stock	Additional Paid-in Capital	Additional Paid-in Capital Public Offering Of Common Stock And Warrants 2019	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Noncontrolling Interest	SmartPharm	SmartPharm Common Stock	SmartPharm Additional Paid-in Capital	Semnur	Semnur Additional Paid-in Capital	Semnur Noncontrolling Interest
Balance, shares (in shares) at Dec. 31, 2018			122,280,092		7,568,182
Balance at Dec. 31, 2018	$ 207,500		$ 13		$ (49,464)	$ 626,658		$ 15	$ (367,750)	$ (1,972)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)			158,699
Exercise of stock options, net	289					289
Issuance of common stock for equity offerings (in shares)			229,168	8,333,334
Issuance of common stock for equity offerings	947	$ 23,322				947	$ 23,322
Issuance of common stock, conversion of notes payable														$ 54,591	$ 27,991	$ 26,600
Stock-based compensation	8,978					8,978
Issuance of 2019 Warrants	4,288					4,288
Adjustment to noncontrolling interest	484									484
Foreign currency translation adjustment	(144)							(144)
Net loss	(293,586)								(229,248)	(64,338)
Balance, shares (in shares) at Sep. 30, 2019			131,001,293		7,568,182
Balance at Sep. 30, 2019	6,669		$ 13		$ (49,464)	692,473		(129)	(596,998)	(39,226)
Balance, shares (in shares) at Jun. 30, 2019			122,645,334		7,568,182
Balance at Jun. 30, 2019	54,616		$ 13		$ (49,464)	665,515		48	(532,583)	(28,913)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)			22,625
Exercise of stock options, net	30					30
Issuance of common stock for equity offerings (in shares)				8,333,334
Issuance of common stock for equity offerings		$ 23,322					$ 23,322
Issuance of common stock, conversion of notes payable														$ (409)	$ (409)
Stock-based compensation	4,015					4,015
Adjustment to noncontrolling interest	484									484
Foreign currency translation adjustment	(177)							(177)
Net loss	(75,212)								(64,415)	(10,797)
Balance, shares (in shares) at Sep. 30, 2019			131,001,293		7,568,182
Balance at Sep. 30, 2019	6,669		$ 13		$ (49,464)	692,473		(129)	(596,998)	(39,226)
Balance, shares (in shares) at Dec. 31, 2019			167,798,120		7,568,182
Balance at Dec. 31, 2019	$ 32,756		$ 18		$ (49,464)	788,122		(270)	(659,818)	(45,832)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	1,213,924		1,213,924
Exercise of stock options, net	$ 5,074					5,074
Issuance of common stock upon issuance of warrants (in shares)			33,080,916
Issuance of common stock upon exercise of warrants	92,736		$ 3			92,733
Issuance of common stock for equity offerings (in shares)			55,815,693
Issuance of common stock for equity offerings	213,009		$ 7			213,002
Issuance of common stock, conversion of notes payable (in shares)												1,832,166
Issuance of common stock, conversion of notes payable											$ 19,421		$ 19,421
Other acquisitions, license agreements and investments paid in equity (in shares)			1,996,803
Other acquisitions, license agreements and investments paid in equity	9,544					9,544
Stock-based compensation	13,312					13,312
Foreign currency translation adjustment	714							714
Net loss	(241,283)								(226,959)	(14,324)
Balance, shares (in shares) at Sep. 30, 2020			261,737,622		7,568,182
Balance at Sep. 30, 2020	145,284		$ 28		$ (49,464)	1,141,208		444	(886,776)	(60,156)
Balance, shares (in shares) at Jun. 30, 2020			231,846,901		7,568,182
Balance at Jun. 30, 2020	80,215		$ 25		$ (49,464)	989,702		(225)	(802,753)	(57,070)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)			287,979
Exercise of stock options, net	1,177					1,177
Issuance of common stock upon issuance of warrants (in shares)			19,956,874
Issuance of common stock upon exercise of warrants	53,876		$ 2			53,874
Issuance of common stock for equity offerings (in shares)			6,816,899
Issuance of common stock for equity offerings	63,765		$ 1			63,764
Issuance of common stock, conversion of notes payable (in shares)												1,832,166
Issuance of common stock, conversion of notes payable											$ 19,421		$ 19,421
Other acquisitions, license agreements and investments paid in equity (in shares)			996,803
Other acquisitions, license agreements and investments paid in equity	6,975					6,975
Stock-based compensation	6,295					6,295
Foreign currency translation adjustment	669							669
Net loss	(87,109)								(84,023)	(3,086)
Balance, shares (in shares) at Sep. 30, 2020			261,737,622		7,568,182
Balance at Sep. 30, 2020	$ 145,284		$ 28		$ (49,464)	$ 1,141,208		$ 444	$ (886,776)	$ (60,156)