Income Taxes (Deferred Tax Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred tax assets
Net operating loss carryforwards	$ 21.1	$ 21.7
Tax credit carryforwards	37.0	42.5
Restructuring and impairment charges	0.3	1.7
Pension and deferred compensation	69.8	62.3
Other	15.1	9.3
Valuation allowance	(20.4)	(19.3)
Total deferred tax assets	122.9	118.2
Deferred tax liabilities:
Accelerated depreciation	42.8	41.2
Other	3.9	6.5
Total deferred tax liabilities	46.7	47.7
Net deferred tax asset	$ 76.2	$ 70.5