SEGMENT AND GEOGRAPHIC INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Segment Reporting Information
Net sales	$ (455,247)	$ (460,900)
Operating income/(loss)	44,101	47,936
Total assets	1,928,872	1,773,100	$ 1,820,606
Cost of sales	291,344	297,320
Selling, general, and administrative expenses	119,643	115,644
Interest Expense	(1,799)	(1,448)
Other income, net	843	706
Foreign Currency Transaction Gain (Loss), before Tax	(1,293)	(4,880)
Restructuring expense	159	0
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	41,852	42,314
Depreciation and amortization	14,433	13,792
Capital Expenditures Incurred In Year, Paid and Not Paid	6,100	7,700
Operating Segments
Segment Reporting Information
Net sales	(496,000)	(495,700)
Intersegment Sales
Segment Reporting Information
Net sales	(40,800)	(34,800)
Operating income/(loss)	(4,100)	(2,700)
Corporate And Eliminations
Segment Reporting Information
Net sales	40,800	34,800
Total assets	61,200	62,700
Depreciation and amortization	800	800
Capital Expenditures Incurred In Year, Paid and Not Paid	400	800
Operating Segments Excluding Intercompany
Segment Reporting Information
Net sales	(455,200)	(460,900)
Segment Reporting, Reconciling Item, Corporate Nonsegment
Segment Reporting Information
Operating income/(loss)	67,400	67,700
Selling, general, and administrative expenses	(19,200)	(17,100)
Segment Reporting, Reconciling Item, Excluding Corporate Nonsegment
Segment Reporting Information
Total assets	1,867,700	1,710,400
Depreciation and amortization	13,600	13,000
Capital Expenditures Incurred In Year, Paid and Not Paid	5,700	6,900
Water Systems | Operating Segments
Segment Reporting Information
Net sales	(287,300)	(286,600)
Operating income/(loss)	43,400	47,100
Total assets	1,228,500	1,053,700
Cost of sales	191,300	189,300
Selling, general, and administrative expenses	52,600	50,200
Restructuring expense	0	0
Depreciation and amortization	10,200	9,600
Capital Expenditures Incurred In Year, Paid and Not Paid	3,200	3,800
Water Systems | Intersegment Sales
Segment Reporting Information
Net sales	(40,800)	(34,800)
Water Systems | Operating Segments Excluding Intercompany
Segment Reporting Information
Net sales	(246,500)	(251,800)
Water Systems | United States & Canada
Segment Reporting Information
Net sales	(134,900)	(137,900)
Water Systems | United States & Canada | Intersegment Sales
Segment Reporting Information
Net sales	(40,800)	(34,800)
Water Systems | Latin America
Segment Reporting Information
Net sales	(39,500)	(41,300)
Water Systems | EMEA
Segment Reporting Information
Net sales	(51,500)	(52,300)
Water Systems | Asia Pacific
Segment Reporting Information
Net sales	(20,600)	(20,300)
Distribution | Operating Segments
Segment Reporting Information
Net sales	(141,900)	(147,000)
Operating income/(loss)	2,100	1,800
Total assets	383,600	402,200
Cost of sales	102,400	107,400
Selling, general, and administrative expenses	37,200	37,800
Restructuring expense	200	0
Depreciation and amortization	2,300	2,300
Capital Expenditures Incurred In Year, Paid and Not Paid	1,700	2,600
Distribution | Intersegment Sales
Segment Reporting Information
Net sales	0	0
Distribution | Operating Segments Excluding Intercompany
Segment Reporting Information
Net sales	(141,900)	(147,000)
Distribution | United States & Canada
Segment Reporting Information
Net sales	(141,900)	(147,000)
Distribution | United States & Canada | Intersegment Sales
Segment Reporting Information
Net sales	0	0
Energy Systems | Operating Segments
Segment Reporting Information
Net sales	(66,800)	(62,100)
Operating income/(loss)	21,900	18,800
Total assets	255,600	254,500
Cost of sales	34,300	32,700
Selling, general, and administrative expenses	10,600	10,600
Restructuring expense	0	0
Depreciation and amortization	1,100	1,100
Capital Expenditures Incurred In Year, Paid and Not Paid	800	500
Energy Systems | Intersegment Sales
Segment Reporting Information
Net sales	0	0
Energy Systems | Operating Segments Excluding Intercompany
Segment Reporting Information
Net sales	(66,800)	(62,100)
Energy Systems | United States & Canada
Segment Reporting Information
Net sales	(52,200)	(46,800)
Energy Systems | All Other
Segment Reporting Information
Net sales	(14,600)	(15,300)
Consolidated
Segment Reporting Information
Net sales	(455,200)	(460,900)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	$ 41,800	$ 42,300