Postretirement Benefit Plans (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Change in benefit obligation:
Benefit obligation at beginning of year			$ 3,133.5
Service cost	4.2	9.6	19.7	28.9
Interest cost	22.3	33.6	94.3	100.9
Actuarial (gains) losses			74.4
Employee contributions			0.2
International plan exchange rate change			(10.8)
Benefits paid			(179.3)
Spinoff of Steel Change in Benefit Obligation			(1,145.1)
Benefit obligation at end of year	1,986.9		1,986.9
Postretirement Benefit Plans [Member]
Change in benefit obligation:
Benefit obligation at beginning of year			515.6
Service cost	0.2	0.7	1.2	2.2
Interest cost	2.9	5.1	13.8	15.9
Actuarial (gains) losses			1.9
International plan exchange rate change			(0.1)
Benefits paid			35.7
Spinoff of Steel Change in Benefit Obligation			(229.8)
Benefit obligation at end of year	$ 266.9		$ 266.9