Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 22, 2019	Jun. 30, 2018
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Trading Symbol	OMP
Entity Registrant Name	Oasis Midstream Partners LP
Entity Central Index Key	0001652133
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Public Float			$ 151,962,333
Common Units
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		20,045,196
Subordinated Units
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		13,750,000