Financial Information for Subsidiary and Guarantor Parent (I.S.) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
CONSOLIDATED STATEMENTS OF OPERATIONS
Sales	$ 1,179.4	$ 1,352.5
Cost of sales	1,065.1	1,145.5
Selling and administrative expenses	85.7	103.4
Income (loss) before interest, other income and income taxes	28.6	103.6
Interest expense, net	14.4	19.9
Other income including equity in income of unconsolidated subsidiaries	1.1	0.4
Income (loss) before income taxes	15.3	84.1
Income tax expense	3.7	25.8
Net income (loss)	11.6	58.3
Less: Net income (loss) attributable to noncontrolling interests	1.6	2.1
Net income (loss) attributable to ATI	10.0	56.2
[ParentCompanyMember]
CONSOLIDATED STATEMENTS OF OPERATIONS
Sales	0	0
Cost of sales	17.5	13.3
Selling and administrative expenses	29.1	43.1
Income (loss) before interest, other income and income taxes	(46.6)	(56.4)
Interest expense, net	11.7	17.0
Other income including equity in income of unconsolidated subsidiaries	73.6	157.5
Income (loss) before income taxes	15.3	84.1
Income tax expense	3.7	25.8
Net income (loss)	11.6	58.3
Less: Net income (loss) attributable to noncontrolling interests	0	0
Net income (loss) attributable to ATI	11.6	58.3
[SubsidiariesMember]
CONSOLIDATED STATEMENTS OF OPERATIONS
Sales	477.1	557.0
Cost of sales	466.7	508.5
Selling and administrative expenses	10.4	10.5
Income (loss) before interest, other income and income taxes	0	38.0
Interest expense, net	2.6	2.6
Other income including equity in income of unconsolidated subsidiaries	(5.4)	1.6
Income (loss) before income taxes	(8.0)	37.0
Income tax expense	(2.5)	14.0
Net income (loss)	(5.5)	23.0
Less: Net income (loss) attributable to noncontrolling interests	0	0
Net income (loss) attributable to ATI	(5.5)	23.0
[NonGuarantorSubsidiariesMember]
CONSOLIDATED STATEMENTS OF OPERATIONS
Sales	702.3	795.5
Cost of sales	580.9	623.7
Selling and administrative expenses	46.2	49.8
Income (loss) before interest, other income and income taxes	75.2	122.0
Interest expense, net	0.1	0.3
Other income including equity in income of unconsolidated subsidiaries	9.2	1.5
Income (loss) before income taxes	84.3	123.2
Income tax expense	29.8	40.8
Net income (loss)	54.5	82.4
Less: Net income (loss) attributable to noncontrolling interests	1.6	2.1
Net income (loss) attributable to ATI	52.9	80.3
[ConsolidationEliminationsMember]
CONSOLIDATED STATEMENTS OF OPERATIONS
Sales	0	0
Cost of sales	0	0
Selling and administrative expenses	0	0
Income (loss) before interest, other income and income taxes	0	0
Interest expense, net	0	0
Other income including equity in income of unconsolidated subsidiaries	(76.3)	(160.2)
Income (loss) before income taxes	(76.3)	(160.2)
Income tax expense	(27.3)	(54.8)
Net income (loss)	(49.0)	(105.4)
Less: Net income (loss) attributable to noncontrolling interests	0	0
Net income (loss) attributable to ATI	$ (49.0)	$ (105.4)