Earnings (Loss) Per Limited Partner Unit (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019		Sep. 30, 2020	Sep. 30, 2019
Net income attributable to Oasis Midstream Partners LP
Distribution declared	$ 19,285	$ 18,149		$ 57,855	$ 51,322
Undistributed loss attributable to Oasis Midstream Partners LP	7,976	13,287		(90,119)	27,855
Net income (loss) attributable to Oasis Midstream Partners LP	27,261	31,436		(32,264)	79,177
General Partner
Net income attributable to Oasis Midstream Partners LP
Distribution declared	1,027	745		3,081	1,474
Undistributed loss attributable to Oasis Midstream Partners LP	0	0		0	0
Net income (loss) attributable to Oasis Midstream Partners LP	$ 1,027	$ 745		$ 3,081	$ 1,474
Common Units
Weighted average units outstanding:
Basic weighted average common units outstanding (shares)	20,045	20,027	[1]	20,044	20,022	[1]
Diluted weighted average common units outstanding (in shares)	20,048	20,038	[1]	20,044	20,039	[1]
Common Units | Limited Partner
Weighted average units outstanding:
Basic weighted average common units outstanding (shares)	20,045	20,027		20,044	20,022
Dilutive effect of restricted awards (shares)	3	11		0	17
Diluted weighted average common units outstanding (in shares)	20,048	20,038		20,044	20,039
Net income attributable to Oasis Midstream Partners LP
Distribution declared	$ 10,833	$ 10,323		$ 32,499	$ 29,567
Undistributed loss attributable to Oasis Midstream Partners LP	4,730	7,878		(53,452)	16,514
Net income (loss) attributable to Oasis Midstream Partners LP	$ 15,563	$ 18,201		$ (20,953)	$ 46,081
Net income attributable to Oasis Midstream Partners LP per limited partner unit
Common units - Basic (in usd per share)	$ 0.78	$ 0.91		$ (1.05)	$ 2.30
Common units - Diluted (in usd per share)	$ 0.78			$ (1.05)	$ 2.30
Anti-dilutive restricted units (shares)	13	7		16	5
Subordinated Units | Limited Partner
Net income attributable to Oasis Midstream Partners LP
Distribution declared	$ 7,425	$ 7,081		$ 22,275	$ 20,281
Undistributed loss attributable to Oasis Midstream Partners LP	3,246	5,409		(36,667)	11,341
Net income (loss) attributable to Oasis Midstream Partners LP	$ 10,671	$ 12,490		$ (14,392)	$ 31,622

[1] Retrospectively adjusted for the transfer of net assets between entities under common control. See Note 2 to our unaudited condensed consolidated financial statements.