Merger of Neoleukin Therapeutics, Inc. and Aquinox Pharmaceuticals, Inc. - Additional information (Detail) - shares		3 Months Ended	9 Months Ended
	Aug. 08, 2019	Sep. 30, 2019	Sep. 30, 2019
Common Stock [Member]
Acquisition Of Assets [Line Items]
Stock issued for acquisition		4,589,771	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