QUARTERLY FINANCIAL INFORMATION (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	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, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Total revenue	$ 295,500	$ 327,200	$ 333,300	$ 311,200	$ 311,000	$ 308,000	$ 311,200	$ 285,900	$ 265,700	$ 251,900	$ 250,700	$ 238,500	$ 1,267,189	$ 1,216,197	$ 1,006,782
Gross profit	78,300	92,700	92,000	84,200	86,600	84,100	85,100	76,400	71,200	67,000	68,900	64,500	347,224	332,208	271,581
Net income	2,100	13,200	13,400	7,300	11,100	8,400	11,600	4,500	6,600	3,000	4,100	3,100	35,775	35,521	16,529
Net income attributable to DXP Enterprises, Inc.	$ 2,200	$ 13,100	$ 13,400	$ 7,300	$ 11,100	$ 8,400	$ 11,600	$ 4,600	$ 6,600	$ 2,900	$ 4,000	$ 3,000	$ 36,035	$ 35,632	$ 16,888
Basic (in dollars per share)	$ 0.12	$ 0.74	$ 0.76	$ 0.41	$ 0.63	$ 0.48	$ 0.66	$ 0.26	$ 0.38	$ 0.17	$ 0.24	$ 0.18	$ 2.04	$ 2.02	$ 0.97
Diluted (in dollars per share)	$ 0.12	$ 0.71	$ 0.73	$ 0.40	$ 0.60	$ 0.46	$ 0.63	$ 0.25	$ 0.37	$ 0.16	$ 0.23	$ 0.17	$ 1.96	$ 1.94	$ 0.93