SEGMENT AND GEOGRAPHIC INFORMATION (Details) - USD ($) $ 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, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information
Net sales	$ 320,100	$ 348,400	$ 355,400	$ 290,700	$ 316,600	$ 341,900	$ 344,000	$ 295,600	$ 1,314,578	$ 1,298,129	$ 1,124,909
Operating income (loss)									127,133	131,994	107,228
Total assets	1,194,743				1,182,365				1,194,743	1,182,365	1,185,400
Depreciation									27,600	29,700	29,900
Long-lived assets	618,100				593,800				618,100	593,800	587,300
Amortization									9,400	8,900	8,600
Capital Expenditures Incurred In Year, Paid And Not Paid									22,100	23,400	33,400
United States
Segment Reporting Information
Net sales									776,600	752,500	609,100
Long-lived assets	394,700				372,600				394,700	372,600	326,100
Foreign
Segment Reporting Information
Net sales									538,000	545,600	515,800
Long-lived assets	223,400				221,200				223,400	221,200	261,200
Operating Segments | Water Systems
Segment Reporting Information
Net sales									781,500	800,100	744,200
Operating income (loss)									103,000	112,700	102,000
Total assets	658,300				679,700				658,300	679,700	695,400
Depreciation									19,000	20,400	20,900
Amortization									6,900	6,500	6,200
Capital Expenditures Incurred In Year, Paid And Not Paid									15,100	18,200	19,100
Operating Segments | Distribution
Segment Reporting Information
Net sales									291,800	269,600	176,700
Operating income (loss)									3,600	3,400	3,700
Total assets	180,200				165,100				180,200	165,100	153,100
Depreciation									2,800	2,200	1,300
Amortization									500	500	400
Capital Expenditures Incurred In Year, Paid And Not Paid									3,900	2,000	1,100
Operating Segments | Fueling Systems
Segment Reporting Information
Net sales									293,600	284,600	244,800
Operating income (loss)									75,800	70,600	60,000
Total assets	283,800				275,700				283,800	275,700	265,700
Depreciation									2,100	2,200	2,200
Amortization									1,900	1,800	1,900
Capital Expenditures Incurred In Year, Paid And Not Paid									1,900	2,200	11,000
Operating Segments | Latin America | Water Systems
Segment Reporting Information
Net sales									124,200	120,200	129,400
Operating Segments | United States & Canada | Water Systems
Segment Reporting Information
Net sales									367,600	372,000	321,900
Operating Segments | United States & Canada | Distribution
Segment Reporting Information
Net sales									291,800	269,600	176,700
Operating Segments | United States & Canada | Fueling Systems
Segment Reporting Information
Net sales									173,500	156,900	144,500
Operating Segments | EMEA | Water Systems
Segment Reporting Information
Net sales									155,600	170,900	165,800
Operating Segments | Asia Pacific | Water Systems
Segment Reporting Information
Net sales									81,800	80,800	86,300
Operating Segments | AllOther | Fueling Systems
Segment Reporting Information
Net sales									120,100	127,700	100,300
Intersegment Sales | Water Systems
Segment Reporting Information
Net sales									52,300	56,200	40,800
Intersegment Sales | Distribution
Segment Reporting Information
Net sales									0	0	0
Intersegment Sales | Fueling Systems
Segment Reporting Information
Net sales									0	0	0
Intersegment Eliminations/Other
Segment Reporting Information
Net sales									(52,300)	(56,200)	(40,800)
Operating income (loss)									(55,300)	(54,700)	(58,500)
Intersegment Eliminations/Other | Intersegment Eliminations/Other
Segment Reporting Information
Total assets	$ 72,400				$ 61,900				72,400	61,900	71,200
Depreciation									3,700	4,900	5,500
Amortization									100	100	100
Capital Expenditures Incurred In Year, Paid And Not Paid									$ 1,200	$ 1,000	$ 2,200