NONCONTROLLING INTERESTS - Effect of Changes (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Effects of changes in noncontrolling interests on equity
Net income (loss) attributable to Select Energy Services, Inc.	$ (245,862)	$ 1,135
Transfers (to) from noncontrolling interests:
Increase in additional paid-in capital as a result of restricted stock issuance, net of forfeitures	1,831	3,021
Increase in additional paid-in capital as a result of issuance of common stock due to vesting of restricted stock units	1	2
(Decrease) increase in additional paid-in capital as a result of the repurchase of SES Holdings LLC Units	(603)	(29)
Increase in additional paid-in capital as a result of the Employee Stock Purchase Plan shares issued	3	2
Change to equity from net income attributable to Select Energy Services, Inc. and transfers from noncontrolling interests	$ (244,630)	$ 4,131

This element represents the total net income attributable to the parent for the period and the effect of net changes during the period impacting the parent's ownership interest in a subsidiary as it relates to the total (consolidated) equity attributable to the parent. The changes to the parent's ownership interest in a subsidiary represented by this element did not result in a deconsolidation of the subsidiary from the consolidated financial statements.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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