Goodwill and Other Intangible Assets, Goodwill by Reporting Unit (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Goodwill [Line Items]
Goodwill	$ 1,092.6	[1]	$ 1,090.9	[1]
United States [Member]
Goodwill [Line Items]
Goodwill	505.9		504.0
Netherlands [Member]
Goodwill [Line Items]
Goodwill	89.7		84.1
United Kingdom [Member]
Goodwill [Line Items]
Goodwill	87.2		84.6
France [Member]
Goodwill [Line Items]
Goodwill	80.2		87.3
Right Management [Member]
Goodwill [Line Items]
Goodwill	62.1		62.1
Other reporting units [Member]
Goodwill [Line Items]
Goodwill	$ 267.5		$ 268.8

[1] Balances were net of accumulated impairment loss of $513.4 as of both September 30, 2014 and December 31, 2013.