SEGMENT REPORTING - Financial Information of Company's Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information, Profit (Loss) [Abstract]
Total Sales	$ 419,249	$ 387,314	$ 1,271,556	$ 1,074,537
Total Segments Operating Income	58,189	48,377	178,434	132,870
Service Centers
Segment Reporting Information, Profit (Loss) [Abstract]
Total Sales	294,458	260,083	888,116	729,977
Total Segments Operating Income	41,441	35,718	130,274	95,437
Innovative Pumping Solutions
Segment Reporting Information, Profit (Loss) [Abstract]
Total Sales	58,963	59,044	184,402	169,890
Total Segments Operating Income	11,155	7,327	31,638	23,122
Supply Chain Services
Segment Reporting Information, Profit (Loss) [Abstract]
Total Sales	65,828	68,187	199,038	174,670
Total Segments Operating Income	$ 5,593	$ 5,332	$ 16,522	$ 14,311