Condensed consolidated statements of stockholders' equity - USD ($) $ in Thousands	Total	Underwritten Public Offering [Member]	Non-voting convertible preferred stock [Member]	Common Stock [Member]	Common Stock [Member] Underwritten Public Offering [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Underwritten Public Offering [Member]	Accumulated Deficit [Member]
Balances at Dec. 31, 2018	$ 72,672					$ 302,759		$ (230,087)
Balances, shares at Dec. 31, 2018				23,537,368
Stock-based compensation	1,078					1,078
Net loss	(2,208)							(2,208)
Balances at Mar. 31, 2019	71,542					303,837		(232,295)
Balances, shares at Mar. 31, 2019				23,537,368
Balances at Dec. 31, 2018	72,672					302,759		(230,087)
Balances, shares at Dec. 31, 2018				23,537,368
Net loss	(61,341)
Balances at Sep. 30, 2019	66,875					358,303		(291,428)
Balances, shares at Sep. 30, 2019			101,927	28,140,243
Balances at Mar. 31, 2019	71,542					303,837		(232,295)
Balances, shares at Mar. 31, 2019				23,537,368
Stock-based compensation	788					788
Net loss	(1)							(1)
Balances at Jun. 30, 2019	72,329					304,625		(232,296)
Balances, shares at Jun. 30, 2019				23,537,368
Options exercised	40					40
Options exercised, shares				13,104
Stock-based compensation	5,151					5,151
Net loss	(59,132)							(59,132)
Balances at Sep. 30, 2019	66,875					358,303		(291,428)
Balances, shares at Sep. 30, 2019			101,927	28,140,243
Issuance of common stock for Former Neoleukin common stock	15,055					15,055
Issuance of common stock for Former Neoleukin common stock, shares				4,589,771
Issuance of convertible preferred stock for Former Neoleukin common stock	33,432					33,432
Issuance of convertible preferred stock for Former Neoleukin common stock, shares			101,927
Issuance of convertible preferred stock for Former Neoleukin common stock, shares			101,927
Balances at Dec. 31, 2019	141,687					441,216		(299,529)
Balances, shares at Dec. 31, 2019				37,996,849
Options exercised	3,392					3,392
Options exercised, shares				376,311
Restricted stock units vested, shares				13,000
Stock-based compensation	683					683
Net loss	(8,642)							(8,642)
Balances at Mar. 31, 2020	137,120					445,291		(308,171)
Balances, shares at Mar. 31, 2020				38,386,160
Balances at Dec. 31, 2019	$ 141,687					441,216		(299,529)
Balances, shares at Dec. 31, 2019				37,996,849
Options exercised, shares	581,270
Net loss	$ (20,637)
Balances at Sep. 30, 2020	200,340					520,506		(320,166)
Balances, shares at Sep. 30, 2020				41,876,590
Balances at Mar. 31, 2020	137,120					445,291		(308,171)
Balances, shares at Mar. 31, 2020				38,386,160
Options exercised	303					303
Options exercised, shares				98,882
Restricted stock units vested, shares				1,500
Stock-based compensation	1,022					1,022
Net loss	(9,746)							(9,746)
Balances at Jun. 30, 2020	128,699					446,616		(317,917)
Balances, shares at Jun. 30, 2020				38,486,542
Issuance of common stock and pre-fundedwarrants, net of commissions andoffering expenses		$ 71,320					$ 71,320
Issuance of common stock and pre-funded warrants, net of commisions and offering expenses, shares					3,262,471
Options exercised	882					882
Options exercised, shares				106,077
Restricted stock units vested, shares				21,500
Stock-based compensation	1,688					1,688
Net loss	(2,249)							(2,249)
Balances at Sep. 30, 2020	$ 200,340					$ 520,506		$ (320,166)
Balances, shares at Sep. 30, 2020				41,876,590