Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities:
Net income	$ 63,375	$ 158,350	$ 166,186
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	87,656	99,059	94,238
(Gain) loss on disposition of property, plant and equipment	(94)	236	71
Stock compensation expense	10,300	13,306	12,158
Loss on sale	6,677	0	0
Non-cash impairment charge related to divestiture	0	5,600	0
Changes in assets and liabilities, net of the effects of acquisitions and divestitures:
Accounts receivable	107,381	29,212	(10,960)
Inventories	2,147	11,482	(12,369)
Prepaid expenses and other current assets	(5,721)	(10,640)	(2,890)
Accounts payable	(9,968)	(22,546)	12,489
Accrued liabilities	(37,430)	2,336	(580)
Deferred income taxes	(5,867)	(12,025)	(18,876)
Long-term retirement benefits	(1,418)	(16,233)	1,632
Long-term tax liability	(6,949)	(6,949)	(6,809)
Other	5,373	(2,887)	2,909
Net cash provided by operating activities	215,462	248,301	237,199
Investing activities:
Proceeds from disposition of property, plant and equipment	449	577	1,374
Proceeds from the sale of businesses, net of cash sold		0
Capital expenditures	(40,698)	(53,286)	(57,273)
Business acquisitions, net of cash acquired	0	(6,061)	(430,487)
Revenue Sharing Program payments	0	0	(5,800)
Other	0	(3,450)	(1,000)
Net cash used in investing activities	(4,187)	(62,220)	(493,186)
Financing activities:
Net change in other borrowings	(5,855)	5,490	(5,145)
Payments on long-term debt	(266,424)	(341,419)	(433,904)
Proceeds from the issuance of long-term debt	98,107	236,552	841,036
Proceeds from the issuance of common stock	1,989	5,492	1,131
Common stock repurchases	(15,550)	(50,347)	(138,275)
Dividends paid	(32,402)	(32,544)	(32,206)
Withholding taxes paid on stock issuances	(3,368)	(6,059)	(5,395)
Other	3,837	(9,158)	(11,678)
Net cash (used) provided by financing activities	(219,666)	(191,993)	215,564
Effect of exchange rate changes on cash flows	6,054	(1,002)	(4,148)
Decrease in cash, cash equivalents and restricted cash	(2,337)	(6,914)	(44,571)
Cash, cash equivalents and restricted cash at beginning of year	93,805	100,719	145,290
Cash, cash equivalents and restricted cash at end of year	91,468	93,805	100,719
Cash and cash equivalents	79,145	93,805	100,719
Prepaid expenses and other current assets
Financing activities:
Restricted cash	(4,944)	0	0
Other assets
Financing activities:
Restricted cash	$ (7,379)	$ 0	$ 0