Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2011
Capitalized Internal Use Software, Useful Life	10
Leasehold improvements, useful life	the shorter of the useful life or the remaining lease term
Number of Reporting Units for Purposes of Annual Goodwill Impairment Test	13
Foreign currency transaction pre-tax loss	$ 1.4	$ 0.6	$ 1.2
Minimum
Property, Plant and Equipment, Useful Life	3 years
Buildings, useful life	10 years
Internal Use Software, Useful Life	3
Finite-Lived Intangible Asset, Useful Life	7 years
Maximum
Property, Plant and Equipment, Useful Life	7 years
Buildings, useful life	35 years
Internal Use Software, Useful Life	7
Finite-Lived Intangible Asset, Useful Life	15 years