CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating activities:
Net income	$ 78,765	$ 196,746	$ 269,601	$ 401,573
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	78,721	80,911	158,980	161,085
Equity-based compensation	9,520	9,080	27,364	24,388
Deferred income taxes	14,634	11,550	20,561	23,641
Other adjustments	4,728	(564)	4,464	164
Changes in certain assets and liabilities:
Accounts receivable	154,352	70,624	280	9,562
Inventories	77,521	64,941	122,026	104,410
Other assets	11,137	7,292	9,596	7,593
Accounts payable	69,523	(58,484)	121,119	(55,278)
Income taxes receivable/payable	7,993	(36,428)	60,378	13,422
Accrued expenses	(20,884)	15,805	(97,078)	(147,534)
Net cash provided by operating activities	486,010	361,473	697,291	543,026
Investing activities:
Purchases of property, plant and equipment	(309,716)	(85,120)	(527,251)	(139,556)
Purchases of short-term investments		(49,465)	(149,359)	(99,142)
Proceeds from maturities of short-term investments	149,648	109,034	341,988	213,771
Acquisition of business, net of cash and restricted cash acquired				(93,412)
Other investing activities	803	913	1,321	1,277
Net cash used in investing activities	(159,265)	(24,638)	(333,301)	(117,062)
Financing activities:
Issuance of current and long-term debt	1,099,774	125,222	1,316,035	246,456
Repayment of current and long-term debt	(1,103,814)	(133,875)	(1,339,571)	(249,146)
Dividends paid	(52,584)	(53,503)	(104,065)	(95,742)
Purchases of treasury stock		(93,136)	(106,529)	(177,444)
Other financing activities	(8,763)	(12)	(14,915)	(5,732)
Net cash used in financing activities	(65,387)	(155,304)	(249,045)	(281,608)
Increase in cash, cash equivalents, and restricted cash	261,358	181,531	114,945	144,356
Cash, cash equivalents, and restricted cash at beginning of period	1,240,984	797,248	1,387,397	834,423
Cash, cash equivalents, and restricted cash at end of period	1,502,342	978,779	1,502,342	978,779
Supplemental disclosure information:
Cash paid for interest	59,668	53,981	68,453	62,587
Cash paid for income taxes, net	$ 1,430	$ 84,516	$ 1,948	$ 86,355