QUARTERLY FINANCIAL INFORMATION (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information [Line Items]
Sales	$ 265,700	$ 251,900	$ 250,700	$ 238,500	$ 222,300	$ 230,000	$ 256,200	$ 253,600	$ 278,600	$ 303,100	$ 323,700	$ 341,600	$ 1,006,782	$ 962,092	$ 1,247,043
Gross profit	71,200	67,000	68,900	64,500	60,600	63,800	71,600	68,800	76,900	85,700	91,300	98,100	271,581	264,802	351,986
Impairment expense									9,800	58,900	0	0
Net income (loss)	6,600	3,000	4,100	3,100	7,100	100	5,100	(5,200)	(3,200)	(52,700)	7,200	9,700	16,529	7,151	(39,070)
Net income (loss) attributable to DXP Enterprises, Inc.	$ 6,600	$ 2,900	$ 4,000	$ 3,000	$ 7,400	$ 200	$ 5,100	$ (5,100)	$ (3,000)	$ (52,400)	$ 7,200	$ 9,700	$ 16,888	$ 7,702	$ (38,536)
Earnings (loss) per share - basic (in dollars per share)	$ 0.38	$ 0.17	$ 0.24	$ 0.18	$ 0.44	$ 0.02	$ 0.36	$ (0.36)	$ (0.20)	$ (3.64)	$ 0.50	$ 0.67	$ 0.97	$ 0.51	$ (2.68)
Earnings (loss) per share - diluted (in dollars per share)	$ 0.37	$ 0.16	$ 0.23	$ 0.17	$ 0.42	$ 0.02	$ 0.34	$ (0.36)					$ 0.93	$ 0.49	$ (2.68)