CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating activities:
Net income	$ 104,277	$ 152,608	$ 373,878	$ 554,181
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	81,752	79,470	240,732	240,555
Equity-based compensation	9,486	8,841	36,850	33,229
Deferred income taxes	10,388	11,311	30,949	34,952
Other adjustments	17,237	(1,116)	21,701	(952)
Changes in certain assets and liabilities:
Accounts receivable	(58,271)	85,633	(57,991)	95,195
Inventories	(38,236)	35,479	83,790	139,889
Other assets	(3,894)	39	5,702	7,632
Accounts payable	645	1,111	121,764	(54,167)
Income taxes receivable/payable	(27,127)	6,293	33,251	19,715
Accrued expenses	55,533	64,533	(41,545)	(83,001)
Net cash provided by operating activities	151,790	444,202	849,081	987,228
Investing activities:
Purchases of property, plant and equipment	(327,647)	(154,131)	(854,898)	(293,687)
Purchases of short-term investments		(34,884)	(149,359)	(134,026)
Proceeds from maturities of short-term investments	69,545	79,508	411,533	293,279
Acquisition of business, net of cash and restricted cash acquired	(59,012)	(3,694)	(59,012)	(97,106)
Other investing activities	380	2,746	1,701	4,023
Net cash used in investing activities	(316,734)	(110,455)	(650,035)	(227,517)
Financing activities:
Issuance of current and long-term debt	295,814	128,230	1,611,849	374,686
Repayment of current and long-term debt	(305,911)	(119,988)	(1,645,482)	(369,134)
Dividends paid	(52,592)	(52,751)	(156,657)	(148,493)
Purchases of treasury stock		(114,950)	(106,529)	(292,394)
Other financing activities	(1,587)	(1,527)	(16,502)	(7,259)
Net cash used in financing activities	(64,276)	(160,986)	(313,321)	(442,594)
Increase (decrease) in cash, cash equivalents, and restricted cash	(229,220)	172,761	(114,275)	317,117
Cash, cash equivalents, and restricted cash at beginning of period	1,502,342	978,779	1,387,397	834,423
Cash, cash equivalents, and restricted cash at end of period	1,273,122	1,151,540	1,273,122	1,151,540
Supplemental disclosure information:
Cash paid for interest	8,597	9,115	77,050	71,702
Cash paid for income taxes, net	$ 43,900	$ 29,794	$ 45,848	$ 116,149