SEGMENT AND GEOGRAPHIC INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Segment Reporting Information
Net sales	$ 459,019	$ 351,190	$ 1,229,345	$ 926,225
Operating income/(loss)	56,594	48,384	141,986	96,138
Total assets	1,545,981		1,545,981		$ 1,272,307
Corporate And Eliminations
Segment Reporting Information
Net sales	(22,900)	(18,100)	(66,900)	(49,300)
Operating income/(loss)	(16,400)	(13,500)	(48,300)	(43,400)
Total assets	60,200		60,200		108,500
Water Systems | Operating Segments
Segment Reporting Information
Net sales	260,700	202,900	705,500	545,400
Operating income/(loss)	36,800	36,600	102,700	84,100
Total assets	909,700		909,700		645,900
Water Systems | United States & Canada
Segment Reporting Information
Net sales	134,800	93,400	333,100	245,100
Water Systems | United States & Canada | Intersegment Sales
Segment Reporting Information
Net sales	22,900	18,100	66,900	49,300
Water Systems | Latin America
Segment Reporting Information
Net sales	36,500	30,100	102,900	82,500
Water Systems | EMEA
Segment Reporting Information
Net sales	46,900	41,800	142,700	115,500
Water Systems | Asia Pacific
Segment Reporting Information
Net sales	19,600	19,500	59,900	53,000
Distribution | Operating Segments
Segment Reporting Information
Net sales	140,200	98,000	380,700	250,500
Operating income/(loss)	12,300	6,400	30,300	10,900
Total assets	293,600		293,600		249,000
Distribution | United States & Canada
Segment Reporting Information
Net sales	140,200	98,000	380,700	250,500
Distribution | United States & Canada | Intersegment Sales
Segment Reporting Information
Net sales	0	0	0	0
Fueling Systems | Operating Segments
Segment Reporting Information
Net sales	81,000	68,400	210,000	179,600
Operating income/(loss)	23,900	18,900	57,300	44,500
Total assets	282,500		282,500		$ 268,900
Fueling Systems | Intersegment Sales
Segment Reporting Information
Net sales	0	0	0	0
Fueling Systems | United States & Canada
Segment Reporting Information
Net sales	58,900	46,400	146,600	119,000
Fueling Systems | All Other
Segment Reporting Information
Net sales	$ 22,100	$ 22,000	$ 63,400	$ 60,600