Financial Information for Subsidiary and Guarantor Parent (I.S.) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
CONSOLIDATED STATEMENTS OF OPERATIONS
Sales	$ 1,135.5	$ 1,357.4	$ 2,314.9	$ 2,709.9
Cost of sales	1,031.7	1,158.5	2,096.8	2,304.0
Selling and administrative expenses	82.1	90.7	167.8	194.1
Income (loss) before interest, other income and income taxes	21.7	108.2	50.3	211.8
Interest expense, net	13.9	18.6	28.3	38.5
Other income including equity in income of unconsolidated subsidiaries	(0.1)	0.1	1.0	0.5
Income (loss) before income taxes	7.7	89.7	23.0	173.8
Income tax expense	1.1	31.0	4.8	56.8
Net income (loss)	6.6	58.7	18.2	117.0
Less: Net income (loss) attributable to noncontrolling interests	2.2	2.3	3.8	4.4
Net income (loss) attributable to ATI	4.4	56.4	14.4	112.6
[ParentCompanyMember]
CONSOLIDATED STATEMENTS OF OPERATIONS
Sales	0	0	0	0
Cost of sales	18.6	13.4	36.1	26.7
Selling and administrative expenses	25.9	34.9	55.0	78.0
Income (loss) before interest, other income and income taxes	(44.5)	(48.3)	(91.1)	(104.7)
Interest expense, net	10.7	15.6	22.4	32.6
Other income including equity in income of unconsolidated subsidiaries	62.9	153.6	136.5	311.1
Income (loss) before income taxes	7.7	89.7	23.0	173.8
Income tax expense	1.1	31.0	4.8	56.8
Net income (loss)	6.6	58.7	18.2	117.0
Less: Net income (loss) attributable to noncontrolling interests	0	0	0	0
Net income (loss) attributable to ATI	6.6	58.7	18.2	117.0
[SubsidiariesMember]
CONSOLIDATED STATEMENTS OF OPERATIONS
Sales	475.8	573.6	952.9	1,130.6
Cost of sales	468.5	526.4	935.2	1,034.9
Selling and administrative expenses	9.5	11.9	19.9	22.4
Income (loss) before interest, other income and income taxes	(2.2)	35.3	(2.2)	73.3
Interest expense, net	2.7	2.6	5.3	5.2
Other income including equity in income of unconsolidated subsidiaries	(6.1)	(12.5)	(11.5)	(10.9)
Income (loss) before income taxes	(11.0)	20.2	(19.0)	57.2
Income tax expense	(0.7)	8.3	(3.2)	22.3
Net income (loss)	(10.3)	11.9	(15.8)	34.9
Less: Net income (loss) attributable to noncontrolling interests	0	0	0	0
Net income (loss) attributable to ATI	(10.3)	11.9	(15.8)	34.9
[NonGuarantorSubsidiariesMember]
CONSOLIDATED STATEMENTS OF OPERATIONS
Sales	659.7	783.8	1,362.0	1,579.3
Cost of sales	544.6	618.7	1,125.5	1,242.4
Selling and administrative expenses	46.7	43.9	92.9	93.7
Income (loss) before interest, other income and income taxes	68.4	121.2	143.6	243.2
Interest expense, net	0.5	0.4	0.6	0.7
Other income including equity in income of unconsolidated subsidiaries	9.2	15.0	18.4	16.5
Income (loss) before income taxes	77.1	135.8	161.4	259.0
Income tax expense	25.3	48.3	55.1	89.1
Net income (loss)	51.8	87.5	106.3	169.9
Less: Net income (loss) attributable to noncontrolling interests	2.2	2.3	3.8	4.4
Net income (loss) attributable to ATI	49.6	85.2	102.5	165.5
[ConsolidationEliminationsMember]
CONSOLIDATED STATEMENTS OF OPERATIONS
Sales	0	0	0	0
Cost of sales	0	0	0	0
Selling and administrative expenses	0	0	0	0
Income (loss) before interest, other income and income taxes	0	0	0	0
Interest expense, net	0	0	0	0
Other income including equity in income of unconsolidated subsidiaries	(66.1)	(156.0)	(142.4)	(316.2)
Income (loss) before income taxes	(66.1)	(156.0)	(142.4)	(316.2)
Income tax expense	(24.6)	(56.6)	(51.9)	(111.4)
Net income (loss)	(41.5)	(99.4)	(90.5)	(204.8)
Less: Net income (loss) attributable to noncontrolling interests	0	0	0	0
Net income (loss) attributable to ATI	$ (41.5)	$ (99.4)	$ (90.5)	$ (204.8)