Equity Method Investments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended			3 Months Ended				12 Months Ended
	Mar. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Mar. 31, 2011 Clemenger Group [Member]	Feb. 01, 2011 Clemenger Group [Member]	Dec. 31, 2011 Affiliate in India [Member]	Dec. 31, 2011 Affiliate in Turkey [Member]	Dec. 31, 2013 Level 3 Income Approach Valuation Technique [Member] Equity Method Investments [Member]
Equity interest in the net income of equity method investments		$ 15.9	$ (15.0)	$ 17.2
Equity interest in the net assets of equity method investments		48.4	69.1
Impairment charge on equity method investment, net		10.7	29.2	0
Fair Value Inputs, weighted average cost of capital									27.00%
Fair Value Inputs, expected long-term growth rate									5.00%
Acquisition of controlling interests in affiliates, effective date of acquisition					Feb. 01, 2011
Acquisition of controlling interests in affiliates, ownership percentage after acquisition						73.70%	100.00%	76.00%
Acquisition of controlling interests in affiliates, ownership percentage before acquisition						46.70%
Remeasurement gain, equity interest in Clemenger Group	123.4	0	0	123.4
Remeasurement gain, acquisition of controlling interests in affiliates		$ 1.6	$ 2.1	$ 15.1