Investments (Details 5) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Fixed maturity investments
Investments
Net Realized Gains (Losses) on Investments	$ (3.5)	$ 11.4
Net Unrealized Gains (Losses) on Investments	18.8	(14.5)
Net Foreign Exchange and Income (Expense) From Certain Derivatives	3.2	(3.8)
Total Changes in Carrying Value Reflected in Revenues	18.5	(6.9)
Equity securities
Investments
Net Realized Gains (Losses) on Investments	2.9	0.3
Net Unrealized Gains (Losses) on Investments	0.7	0.8
Net Foreign Exchange and Income (Expense) From Certain Derivatives	(1.8)	(1.1)
Total Changes in Carrying Value Reflected in Revenues	1.8
Other investments
Investments
Net Realized Gains (Losses) on Investments	0.5	(2.6)
Net Unrealized Gains (Losses) on Investments	3.3	3.9
Net Foreign Exchange and Income (Expense) From Certain Derivatives	(3.2)	5.6
Total Changes in Carrying Value Reflected in Revenues	$ 0.6	$ 6.9