Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 segment	Mar. 31, 2013	Dec. 31, 2013
Segment Information
Number of reporting segments	3
Segment Reporting Information
Total net sales	$ 1,830,082	$ 1,795,696
Operating income (loss)	80,932	96,232
Income (loss) before income taxes	50,994	62,649
Depreciation and amortization	57,568	57,061
Capital expenditures	24,841	45,346
Assets	5,913,857	5,956,574	5,933,006
Liabilities	3,279,527	3,450,570
U.S.
Segment Reporting Information
Total net sales	1,715,518	1,681,974
Non-U.S.
Segment Reporting Information
Total net sales	114,564	113,722
Steel Operations | U.S.
Segment Reporting Information
Total net sales	1,061,079	1,011,195
Steel Operations | Non-U.S.
Segment Reporting Information
Total net sales	56,519	50,117
Metals Recycling/Ferrous Resources | U.S.
Segment Reporting Information
Total net sales	517,957	557,611
Metals Recycling/Ferrous Resources | Non-U.S.
Segment Reporting Information
Total net sales	57,817	63,517
Steel Fabrication Operations | U.S.
Segment Reporting Information
Total net sales	115,861	93,797
Other | U.S.
Segment Reporting Information
Total net sales	20,621	19,371
Other | Non-U.S.
Segment Reporting Information
Total net sales	228	88
Operating segment
Segment Reporting Information
Total net sales	1,830,082	1,795,696
Operating segment | Steel Operations
Segment Reporting Information
Total net sales	1,161,330	1,122,360
Operating income (loss)	105,643	119,301
Income (loss) before income taxes	91,998	105,007
Depreciation and amortization	27,377	26,387
Capital expenditures	18,606	24,726
Assets	2,731,246	2,566,642
Liabilities	576,643	557,404
Operating segment | Metals Recycling/Ferrous Resources
Segment Reporting Information
Total net sales	919,702	897,492
Operating income (loss)	(15,519)	(9,824)
Income (loss) before income taxes	(22,696)	(17,854)
Depreciation and amortization	26,621	27,136
Capital expenditures	5,779	19,069
Assets	2,537,892	2,529,951
Liabilities	613,611	526,457
Operating segment | Steel Fabrication Operations
Segment Reporting Information
Total net sales	115,861	94,375
Operating income (loss)	3,126	1,530
Income (loss) before income taxes	1,652	(76)
Depreciation and amortization	2,222	2,057
Capital expenditures	311	881
Assets	263,688	254,176
Liabilities	17,022	15,646
Operating segment | Other
Segment Reporting Information
Total net sales	27,522	24,854
Operating income (loss)	(16,545)	(16,439)
Income (loss) before income taxes	(24,187)	(26,092)
Depreciation and amortization	1,399	1,532
Capital expenditures	145	670
Assets	609,206	822,064
Liabilities	2,290,332	2,556,590
Eliminations
Segment Reporting Information
Total net sales	(394,333)	(343,385)
Operating income (loss)	4,227	1,664
Income (loss) before income taxes	4,277	1,664
Depreciation and amortization	(51)	(51)
Assets	(228,175)	(216,259)
Liabilities	(218,081)	(205,527)
Eliminations | Steel Operations
Segment Reporting Information
Total net sales	43,732	61,048
Eliminations | Metals Recycling/Ferrous Resources
Segment Reporting Information
Total net sales	343,928	276,364
Eliminations | Steel Fabrication Operations
Segment Reporting Information
Total net sales		578
Eliminations | Other
Segment Reporting Information
Total net sales	$ 6,673	$ 5,395