Pension And Other Postretirement Benefit Plans (Fair Value Measurements Of Plan Assets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Plan assets fair value	$ 298.7	[1]	$ 281.6	[1]
Foreign Equity Security [Member]
Plan assets fair value	62.2		56.8
Cash and Cash Equivalents [Member]
Plan assets fair value	10.4	[1]	7.1	[1]
Fixed Income Securities [Member] | Guaranteed insurance contracts [Member]
Plan assets fair value	5.2	[1]	4.6	[1]
Quoted prices in active markets for identical assets (Level 1) [Member]
Plan assets fair value	75.0		79.1
Significant Other Observable Inputs (Level 2) [Member]
Plan assets fair value	223.7		202.5
Significant Other Observable Inputs (Level 2) [Member] | Cash and Cash Equivalents [Member]
Plan assets fair value	10.4		7.1
Significant Other Observable Inputs (Level 2) [Member] | Fixed Income Securities [Member] | Guaranteed insurance contracts [Member]
Plan assets fair value	5.2		4.6
Equity Securities [Member] | U.S. large-cap [Member]
Plan assets fair value	79.1	[1]	73.3	[1]
Equity Securities [Member] | U.S. mid-cap [Member]
Plan assets fair value	25.5	[1]	26.7	[1]
Equity Securities [Member] | U.S. small-cap [Member]
Plan assets fair value	29.5	[1]	31.0	[1]
Equity Securities [Member] | Foreign Equity Security [Member]
Plan assets fair value	48.9	[1]	50.0	[1]
Equity Securities [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | U.S. mid-cap [Member]
Plan assets fair value	25.5		26.7
Equity Securities [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | U.S. small-cap [Member]
Plan assets fair value	29.5		31.0
Equity Securities [Member] | Quoted prices in active markets for identical assets (Level 1) [Member] | Foreign Equity Security [Member]
Plan assets fair value	20.0		21.4
Equity Securities [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. large-cap [Member]
Plan assets fair value	79.1		73.3
Equity Securities [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Equity Security [Member]
Plan assets fair value	28.9		28.6
Diversified Bond Fund [Member] | Fixed Income Securities [Member]
Plan assets fair value	84.7	[1],[2]	75.5	[1],[2]
Diversified Bond Fund [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fixed Income Securities [Member]
Plan assets fair value	84.7	[2]	75.5	[2]
Foreign Government Bonds [Member] | Fixed Income Securities [Member]
Plan assets fair value	7.9	[1]	6.7	[1]
Foreign Government Bonds [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fixed Income Securities [Member]
Plan assets fair value	7.9		6.7
Foreign Corporate Notes and Bonds [Member] | Fixed Income Securities [Member]
Plan assets fair value	7.5	[1]	6.7	[1]
Foreign Corporate Notes and Bonds [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fixed Income Securities [Member]
Plan assets fair value	$ 7.5		$ 6.7

[1] There were no assets categorized as Level 3 at December 31, 2011 and 2010, respectively.

[2] Diversified bond fund consists of U.S. Treasury bonds, mortgage backed securities, and corporate bonds.