Goodwill and Other Intangible Assets - Schedule of Change in Net Carrying Amount of Goodwill by Segment (Detail) $ in Thousands	6 Months Ended
	Jul. 02, 2016 USD ($)
Goodwill [Line Items]
Balance, beginning of period	$ 2,011,278
Translation	19,273
Balance, end of period	2,030,551
Steel Mills [Member]
Goodwill [Line Items]
Balance, beginning of period	590,634
Balance, end of period	590,634
Steel Products [Member]
Goodwill [Line Items]
Balance, beginning of period	691,067
Translation	19,273
Balance, end of period	710,340
Raw Materials [Member]
Goodwill [Line Items]
Balance, beginning of period	729,577
Balance, end of period	$ 729,577