CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash Flows from Operating Activities:
Net income	$ 408,375	$ 430,158	$ 189,580
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation expense from property, plant and equipment and financing leases	153,472	147,962	157,320
Amortization of intangible assets and deferred proceeds, net	23,494	23,628	23,245
Fair value adjustment of acquisition related contingent consideration	159,354	32,301	146,308
Pension plan settlement expense	112,796	0	0
Deferred income taxes	(49,021)	8,977	(9,183)
Loss on sale of property, plant and equipment	7,181	5,642	5,921
Amortization of debt costs	991	1,012	1,256
Deferred payroll taxes under CARES Act	0	(18,739)	(18,739)
Impairment and abandonment of property, plant and equipment	0	0	3,200
Change in current assets less current liabilities	29,138	(74,784)	30,595
Change in other noncurrent assets	12,708	31,779	16,003
Change in other noncurrent liabilities	(47,798)	(33,430)	(23,751)
Total adjustments	402,315	124,348	332,175
Net cash provided by operating activities	810,690	554,506	521,755
Cash Flows from Investing Activities:
Additions to property, plant and equipment	(282,304)	(298,611)	(155,693)
Investment in equity method investees	(13,741)	(3,094)	(2,531)
Proceeds from the sale of property, plant and equipment	695	7,369	5,274
Acquisition of distribution rights	0	(30,649)	(8,993)
Net cash used in investing activities	(295,350)	(324,985)	(161,943)
Cash Flows from Financing Activities:
Cash dividends paid	(46,868)	(9,374)	(9,374)
Payments of acquisition related contingent consideration	(28,208)	(36,515)	(39,097)
Payments on financing lease obligations	(2,303)	(2,988)	(4,778)
Debt issuance fees	(340)	(310)	(1,542)
Payments on term loan facility and senior notes	0	(125,000)	(287,500)
Borrowings under term loan facility	0	0	70,000
Payments on revolving credit facility	0	0	(55,000)
Borrowings under revolving credit facility	0	0	55,000
Net cash used in financing activities	(77,719)	(174,187)	(272,291)
Net increase in cash	437,621	55,334	87,521
Cash at beginning of year	197,648	142,314	54,793
Cash at end of year	$ 635,269	$ 197,648	$ 142,314