Employee Benefits, Net Periodic Benefit Costs and Charges Relating To All Other Employee Benefit Plans(Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
VEBAs:
Total net periodic postretirement benefit cost (income) relating to VEBAs	$ 0.6	$ (5.6)
Pre-tax loss on settlement of Union VEBA		0
Deferred compensation plan	(0.4)	(0.2)
Defined contribution plans	(4.0)	(4.0)
Multiemployer pension plans	0.9	0.9
Charges Relating To Other Benefit Plans	5.3	5.1
Total other employee benefit plans	498.1	(0.5)
Fabricated Products
VEBAs:
Total other employee benefit plans	4.6	4.6
All Other
VEBAs:
Total other employee benefit plans	493.5	(5.1)
VEBAs
VEBAs:
Service cost	0	0.6
Interest cost	0.7	4.1
Expected return on plan assets	(1.1)	(12.8)
Amortization of prior service cost	0.7	2.8
Amortization of net actuarial loss (gain)	0.3	(0.3)
Total net periodic postretirement benefit cost (income) relating to VEBAs	0.6	(5.6)
Pre-tax loss on settlement of Union VEBA	492.2	0
Total Charges Relating To VEBAs	$ 492.8	$ (5.6)