Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	BSQR
Entity Registrant Name	BSQUARE CORP /WA
Entity Central Index Key	0001054721
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		12,982,252
Entity Current Reporting Status	Yes
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity File Number	000-27687
Entity Tax Identification Number	91-1650880
Entity Address, Address Line One	110 110th Avenue NE
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Bellevue
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98004
City Area Code	425
Local Phone Number	519-5900
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common stock, no par value
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	WA
Document Quarterly Report	true
Document Transition Report	false