CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 95,999	$ 105,517	$ 78,593
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	36,977	38,604	38,506
Non-cash lease expense	11,699	0	0
Share-based compensation	8,957	8,450	7,109
Income taxes-U.S. Tax Cuts and Jobs Act	0	0	10,198
Deferred income taxes	(2,566)	(5,164)	(6,311)
Loss on disposals of plant and equipment	891	311	1,572
Gain on equity investment	0	0	(5,165)
Foreign exchange (income)/expense	1,641	706	(1,025)
Changes in assets and liabilities, net of acquisitions:
Receivables	1,076	(8,194)	9,948
Inventory	17,228	(4,775)	(46,372)
Accounts payable and accrued expenses	6,770	1,677	(11,071)
Operating leases	(11,698)	0	0
Income taxes	6,449	(1,771)	(2,513)
IncreaseDecreaseinTCJATaxPayable	0	(6,510)	0
Employee benefit plans	(1,443)	(2,291)	(2,529)
Other, net	5,696	1,875	(4,186)
Net cash flows from operating activities	177,676	128,435	66,754
Cash flows from investing activities:
Additions to property, plant, and equipment	(21,855)	(22,432)	(33,484)
Proceeds from sale of property, plant, and equipment	866	724	211
Cash paid for acquisitions, net of cash acquired	(20,827)	(44,971)	(51,783)
Other, net	10	387	355
Net cash flows from investing activities	(41,806)	(66,292)	(84,701)
Cash flows from financing activities:
Proceeds from issuance of debt	264,389	232,638	193,358
Repayment of debt	(355,332)	(251,623)	(191,476)
Proceeds from issuance of common stock	3,194	8,999	4,497
Purchases of common stock	(10,741)	(34,188)	(3,621)
Dividends paid	(27,671)	(22,612)	(20,289)
Purchase of redeemable noncontrolling shares	(487)	0	(5,047)
Net cash flows from financing activities	(126,648)	(66,786)	(22,578)
Effect of exchange rate changes on cash	(3,990)	(3,417)	3,427
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	5,232	(8,060)	(37,098)
Cash and equivalents at beginning of period	59,173	67,233	104,331
Cash and equivalents at end of period	64,405	59,173	67,233
Cash paid for income taxes, net of refunds	16,949	27,025	25,810
Cash paid for interest	8,388	10,792	9,373
Non-cash items:
Additions to property, plant, and equipment, not yet paid	1,509	1,158	168
Right-of-Use Assets obtained in exchange for new operating lease liabilities	4,922	0	0
Payable to sellers of acquired entities	$ 845	$ 1,000	$ 0