Shareholders' Equity - Schedule of Earnings per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended					9 Months Ended
	Apr. 16, 2019	Jun. 30, 2019	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Basic net (loss) income attributable to Brigham Minerals, Inc. shareholders	$ 314	$ (2,170)	$ (9,465)	$ (4,050)	$ 4,706	$ 3,146	$ 534	$ (8,809)	$ 1,824
Less: net income attributable to Brigham Minerals, Inc. shareholders pre-IPO			0			0		0	(848)
Basic net (loss) income attributable to Brigham Minerals, Inc. shareholders post-IPO			$ (9,465)			$ 3,146		$ (8,809)	$ 976
Denominator:
Basic weighted average shares outstanding (in shares)			40,124			21,838		36,475	13,299
Basic EPS attributable to Brigham Minerals, Inc. shareholders (in dollars per share)			$ (0.24)			$ 0.14		$ (0.24)	$ 0.07
Numerator:
Effect of time-based restricted stock awards			$ 0			$ 0		$ 0	$ 0
Diluted net (loss) income attributable to Brigham Minerals, Inc. shareholders			$ (9,465)			$ 3,146		$ (8,809)	$ 976
Denominator:
Basic weighted average shares outstanding (in shares)			40,124			21,838		36,475	13,299
Effects of dilutive securities:
Time-based restricted stock awards (in shares)			0			88		0	47
Diluted weighted average shares outstanding (in shares)			40,124			21,926		36,475	13,346
Diluted EPS attributable to Brigham Minerals, Inc. shareholders (in dollars per share)			$ (0.24)			$ 0.14		$ (0.24)	$ 0.07