Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statement Comprehensive Income [Line Items]
Net income	$ 34.8	$ 192.4	$ 218.9
Unrealized Gain (Loss) on Investments [Abstract]
Pension, SERP and Retiree Medical adjustments, Net of Tax	(30.5)	(52.9)	(15.5)
Foreign currency translation adjustments, Net of Tax	6.3	(0.5)	(4.0)
Other Comprehensive Income Unrealized Gain Loss On Intercompany Loan Net Of Tax	2.2		(2.0)
Total Comprehensive Income, Net of Tax	15.8	141.5	203.3
Interest rate swaps [Member]
Unrealized Gain (Loss) on Investments [Abstract]
Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax		(4.2)	(3.0)
Reclassification Adjustment on Derivatives, Net of Tax	2.9	5.3	9.4
Foreign currency hedge contracts [Member]
Unrealized Gain (Loss) on Investments [Abstract]
Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax		0.5	(1.3)
Reclassification Adjustment on Derivatives, Net of Tax	0.1	0.2	0.8
Other Comprehensive Income Reclassification Adjustment On Derivatives Realized In Other Assets Net Of Tax		$ 0.7