Merger of Neoleukin Therapeutics, Inc. and Aquinox Pharmaceuticals, Inc. - Additional information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Aug. 08, 2019	Dec. 31, 2019
Acquisition Of Assets [Line Items]
Finite-lived Intangible assets, fair value disclosure		$ 47,716
In Process Research and Development [Member]
Acquisition Of Assets [Line Items]
Finite-lived Intangible assets, fair value disclosure	$ 47,700
Common Stock [Member]
Acquisition Of Assets [Line Items]
Stock issued for acquisition		4,589,771
Aquinox [Member] | Common Stock [Member]
Acquisition Of Assets [Line Items]
Stock issued for acquisition	4,589,771
Non-voting convertible preferred stock [Member] | Aquinox [Member]
Acquisition Of Assets [Line Items]
Stock issued for acquisition	101,927