EARNINGS PER SHARE DATA - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Basic:
Weighted average shares outstanding (in shares)													17,748	17,592	17,553
Net income (loss) attributable to DXP Enterprises, Inc.	$ (1,900)	$ (34,700)	$ 2,100	$ 5,700	$ 2,200	$ 13,100	$ 13,400	$ 7,300	$ 11,100	$ 8,400	$ 11,600	$ 4,600	$ (28,726)	$ 36,035	$ 35,632
Convertible preferred stock dividend													(90)	(90)	(90)
Net income (loss) attributable to common shareholders													$ (28,816)	$ 35,945	$ 35,542
Per share amount (in dollars per share)	$ (0.11)	$ (1.95)	$ 0.12	$ 0.31	$ 0.12	$ 0.74	$ 0.76	$ 0.41	$ 0.63	$ 0.48	$ 0.66	$ 0.26	$ (1.62)	$ 2.04	$ 2.02
Diluted:
Weighted average shares outstanding (in shares)													17,748	17,592	17,553
Assumed conversion of convertible preferred stock (in shares)													0	840	840
Total dilutive shares (in shares)													17,748	18,432	18,393
Net income (loss) attributable to common shareholders													$ (28,816)	$ 35,945	$ 35,542
Convertible preferred stock dividend													0	90	90
Net income (loss) attributable to DXP Enterprises, Inc.													$ (28,816)	$ 36,035	$ 35,632
Per share amount (in dollars per share)	$ (0.11)	$ (1.95)	$ 0.12	$ 0.31	$ 0.12	$ 0.71	$ 0.73	$ 0.40	$ 0.60	$ 0.46	$ 0.63	$ 0.25	$ (1.62)	$ 1.96	$ 1.94