Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Condensed Consolidated Statements of Operations (Unaudited) [Abstract]
Net sales	$ 172,994	$ 200,708
Cost of goods sold	152,280	168,640
Selling, general, and administrative expenses	25,138	37,720
Operating loss	(4,424)	(5,652)
Other income (expense):
Interest income	128	171
Interest expense, net of capitalized interest	(4,878)	(1,516)
Foreign exchange (loss) gain	(381)	545
Other income	21	115
Loss before benefit from income taxes	(9,534)	(6,337)
Benefit from income taxes	(2,709)	(1,269)
Net loss	(6,825)	(5,068)
Income attributable to noncontrolling interest, net of tax	(27)	(637)
Net loss attributable to Globe Specialty Metals, Inc.	$ (6,852)	$ (5,705)
Weighted average shares outstanding:
Basic (in shares)	75,310,143	75,050,560
Diluted (in shares)	75,310,143	75,050,560
Loss per common share:
Basic (in dollars per share)	$ (0.09)	$ (0.08)
Diluted (in dollars per share)	$ (0.09)	$ (0.08)
Cash dividends declared per common share (in dollars per share)	$ 0.07	$ 0.06