Segment Information - Results Footnote (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Operating income (loss)
Corporate SG & A	$ (109,299)	$ (106,250)	$ (222,197)	$ (217,288)
Profit sharing	(9,092)	(22,871)	(30,546)	(46,548)
Operating income (loss)	158,850	285,032	432,536	576,874
Gross profit	284,431	421,166	699,660	854,736
Assets
Cash and equivalents	1,496,458		1,496,458		$ 1,381,460
Short-term Investments	69,546		69,546		262,174
Accounts receivable	844,100		844,100
Inventories	1,567,017		1,567,017		1,689,043
Property, plant and equipment, net	3,587,450		3,587,450		3,135,886
Other assets	100,031		100,031		106,038
Total assets	8,468,341		8,468,341		$ 8,275,765
Operating Segment | Other
Operating income (loss)
Corporate SG & A	(14,500)	(18,000)	(31,700)	(40,600)
Company-wide equity-based compensation	(9,700)	(8,400)	(17,900)	(17,400)
Profit sharing	(8,200)	(21,300)	(29,500)	(44,300)
Other, net	300	(1,500)	700	(3,800)
Operating income (loss)	(32,089)	(49,153)	(78,444)	(106,073)
Assets
Cash and equivalents	1,418,400		1,418,400
Short-term Investments	69,500		69,500
Accounts receivable	11,400		11,400
Inventories	26,900		26,900
Property, plant and equipment, net	148,200		148,200
Intra-company debt	6,500		6,500
Other assets	38,100		38,100
Total assets	1,718,951		1,718,951
Operating Segment | Metals Recycling Operations
Operating income (loss)
Operating income (loss)	(8,715)	7,619	(3,187)	24,581
Assets
Total assets	867,866		867,866
Eliminations
Operating income (loss)
Operating income (loss)	4,456	4,491	1,412	6,590
Gross profit	4,500	$ 4,500	1,400	$ 6,600
Assets
Accounts receivable	(35,500)		(35,500)
Intra-company debt	(6,500)		(6,500)
Other assets	(6,900)		(6,900)
Total assets	$ (48,911)		$ (48,911)