Segment Information (Details 3) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Operating income (loss)
Gross profit increase (decrease) from intra-company sales	$ 288,512,000	$ 197,192,000	$ 674,587,000	$ 521,148,000
Assets elimination
Elimination of intra-company receivables	1,058,668,000		1,058,668,000		720,600,000
Other	94,047,000		94,047,000		115,083,000
Total assets	7,578,283,000	5,874,305,000	7,578,283,000	5,874,305,000	5,933,006,000
Liabilities elimination
Elimination of intra-company payables	640,121,000		640,121,000		414,932,000
Liabilities	4,540,294,000	3,316,517,000	4,540,294,000	3,316,517,000
Eliminations
Operating income (loss)
Gross profit increase (decrease) from intra-company sales	1,100,000	(2,100,000)	3,900,000	2,500,000
Assets elimination
Elimination of intra-company receivables	(80,700,000)	(46,900,000)	(80,700,000)	(46,900,000)
Elimination of intra-company debt	(160,200,000)	(153,600,000)	(160,200,000)	(153,600,000)
Other	(9,600,000)	(10,000,000)	(9,600,000)	(10,000,000)
Total assets	(250,497,000)	(210,502,000)	(250,497,000)	(210,502,000)
Liabilities elimination
Elimination of intra-company payables	(81,200,000)	(47,300,000)	(81,200,000)	(47,300,000)
Elimination of intra-company debt	(160,200,000)	(153,600,000)	(160,200,000)	(153,600,000)
Other	1,200,000	600,000	1,200,000	600,000
Liabilities	(240,214,000)	(200,304,000)	(240,214,000)	(200,304,000)
Severstal Columbus LLC
Acquisition
Acquisition and related costs	$ 25,000,000		$ 25,000,000