Fair Value Measurements (Details) (Fair Value, Inputs, Level 1 [Member], USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Fair Value, Inputs, Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Investment in marketable equity securities	$ 10.1	[1]	$ 8.4	[1]

[1] Investment in marketable equity securities is recorded in Other Assets, net in the accompanying Consolidated Balance Sheets.