Segment Information - Results Footnote (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating income (loss)
Corporate SG & A									$ (477,450)	$ (436,498)	$ (416,640)
Company-wide equity-based compensation									(50,700)	(43,300)	(38,700)
Profit sharing									(61,728)	(78,029)	(155,985)
Asset impairment charges									(19,409)
Operating income (loss)	$ 258,750	$ 155,856	$ 158,850	$ 273,686	$ 181,961	$ 228,045	$ 285,032	$ 291,842	847,142	986,880	1,722,409
Gross profit	442,253	$ 292,815	$ 284,431	$ 415,229	316,409	$ 359,839	$ 421,166	$ 433,570	1,434,728	1,530,984	2,322,814
Assets
Cash and equivalents	1,368,618				1,381,460				1,368,618	1,381,460
Short-term Investments	0				262,174				0	262,174
Inventories	1,843,548				1,689,043				1,843,548	1,689,043
Property, plant and equipment, net	4,105,569				3,135,886				4,105,569	3,135,886
Other assets	119,743				106,038				119,743	106,038
Total assets	9,265,562				8,275,765				9,265,562	8,275,765
Operating Segment | Other
Operating income (loss)
Corporate SG & A									(57,900)	(66,100)	(58,000)
Company-wide equity-based compensation									(48,500)	(40,600)	(36,400)
Profit sharing									(58,300)	(73,600)	(149,800)
Asset impairment charges									(19,400)
Other, net									(4,400)	(5,900)	(9,000)
Operating income (loss)									(188,525)	(186,159)	(253,195)
Assets
Cash and equivalents	1,276,100				1,298,800				1,276,100	1,298,800
Short-term Investments					262,200					262,200
Accounts receivable	17,000				17,100				17,000	17,100
Inventories	84,700				37,000				84,700	37,000
Property, plant and equipment, net	136,000				149,800				136,000	149,800
Intra-company debt	9,100				8,100				9,100	8,100
Other assets	48,300				75,700				48,300	75,700
Total assets	1,571,188				1,848,711				1,571,188	1,848,711
Operating Segment | Metals Recycling Operations
Operating income (loss)
Operating income (loss)									32,991	16,308	75,891
Assets
Total assets	1,116,051				940,250				1,116,051	940,250
Eliminations
Operating income (loss)
Operating income (loss)									(7,379)	7,078	(2,040)
Gross profit									(8,500)	6,200	$ (2,100)
Assets
Accounts receivable	(61,200)				(54,700)				(61,200)	(54,700)
Intra-company debt	(9,100)				(8,100)				(9,100)	(8,100)
Other assets	(16,400)				(7,900)				(16,400)	(7,900)
Total assets	$ (86,697)				$ (70,707)				$ (86,697)	$ (70,707)