CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income	$ 105,517	$ 78,593	$ 79,315
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	38,604	38,506	35,534
Share-based compensation	8,450	7,109	6,889
Income taxes-U.S. Tax Cuts and Jobs Act	0	10,198	0
Deferred income taxes	(5,164)	(6,311)	2,978
Loss on disposals of plant and equipment	311	1,572	751
Gain on equity investment	0	(5,165)	0
Foreign exchange (income)/expense	706	(1,025)	(1,057)
Changes in assets and liabilities, net of acquisitions:
Receivables	(8,194)	9,948	(21,334)
Inventory	(4,775)	(46,372)	(7,636)
Accounts payable and accrued expenses	1,677	(11,071)	11,782
Income taxes	(1,771)	(2,513)	4,709
IncreaseDecreaseinTCJATaxPayable	(6,510)	0	0
Employee benefit plans	(2,291)	(2,529)	(1,049)
Other, net	1,875	(4,186)	4,492
Net cash flows from operating activities	128,435	66,754	115,374
Cash flows from investing activities:
Additions to property, plant, and equipment	(22,432)	(33,484)	(39,136)
Proceeds from sale of property, plant, and equipment	724	211	6,028
Cash paid for acquisitions, net of cash acquired	(44,971)	(51,783)	(1,007)
Other, net	387	355	346
Net cash flows from investing activities	(66,292)	(84,701)	(33,769)
Cash flows from financing activities:
Proceeds from issuance of debt	232,638	193,358	64,681
Repayment of debt	(251,623)	(191,476)	(95,066)
Proceeds from issuance of common stock	8,999	4,497	5,243
Purchases of common stock	(34,188)	(3,621)	(7,422)
Dividends paid	(22,612)	(20,289)	(19,137)
Purchase of redeemable noncontrolling shares	0	(5,047)	0
Net cash flows from financing activities	(66,786)	(22,578)	(51,701)
Effect of exchange rate changes on cash	(3,417)	3,427	(7,134)
Net change in cash and equivalents	(8,060)	(37,098)	22,770
Cash and equivalents at beginning of period	67,233	104,331	81,561
Cash and equivalents at end of period	59,173	67,233	104,331
Cash paid for income taxes, net of refunds	27,025	25,810	22,296
Cash paid for interest	10,792	9,373	8,965
Non-cash items:
Additions to property, plant, and equipment, not yet paid	1,158	168	366
Bombas Leao S.A.
Noncash or Part Noncash Acquisitions [Line Items]
Noncash or Part Noncash Acquisition, Payables Assumed	0	0	24
Industrias Rotor Pump S.A.
Noncash or Part Noncash Acquisitions [Line Items]
Noncash or Part Noncash Acquisition, Payables Assumed	$ 1,000	$ 0	$ 0