9. Derivative Instruments (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2011 As restated and amended [Member]	Sep. 30, 2011 As restated and amended [Member]	Sep. 30, 2012 Interest rate swaps [Member]	Sep. 30, 2012 Interest rate swaps [Member]	Sep. 30, 2011 Interest rate swaps [Member] As restated and amended [Member]	Sep. 30, 2011 Interest rate swaps [Member] As restated and amended [Member]	Sep. 30, 2012 Variance Swaps [member]	Sep. 30, 2012 Variance Swaps [member]	Sep. 30, 2011 Variance Swaps [member] As restated and amended [Member]	Sep. 30, 2011 Variance Swaps [member] As restated and amended [Member]	Sep. 30, 2012 Swaptions [Member]	Sep. 30, 2012 Swaptions [Member]	Sep. 30, 2011 Swaptions [Member] As restated and amended [Member]	Sep. 30, 2011 Swaptions [Member] As restated and amended [Member]	Sep. 30, 2012 Put options [Member]	Sep. 30, 2012 Put options [Member]	Sep. 30, 2011 Put options [Member] As restated and amended [Member]	Sep. 30, 2011 Put options [Member] As restated and amended [Member]	Sep. 30, 2012 Call options [Member]	Sep. 30, 2012 Call options [Member]	Sep. 30, 2011 Call options [Member] As restated and amended [Member]	Sep. 30, 2011 Call options [Member] As restated and amended [Member]	Sep. 30, 2012 Equity futures	Sep. 30, 2012 Equity futures	Sep. 30, 2011 Equity futures As restated and amended [Member]	Sep. 30, 2011 Equity futures As restated and amended [Member]	Sep. 30, 2012 Embedded Derivatives [Member]	Sep. 30, 2012 Embedded Derivatives [Member]	Sep. 30, 2011 Embedded Derivatives [Member] As restated and amended [Member]	Sep. 30, 2011 Embedded Derivatives [Member] As restated and amended [Member]	Sep. 30, 2012 Related party reinsurance derivatives [Member]	Sep. 30, 2012 Related party reinsurance derivatives [Member]	Sep. 30, 2011 Related party reinsurance derivatives [Member] As restated and amended [Member]	Sep. 30, 2011 Related party reinsurance derivatives [Member] As restated and amended [Member]
Total derivative instrument realized gains (losses) recognized in earnings	$ (15.6)	$ (30.9)	$ (3.4)	$ (7.7)	$ (1.1)	$ (0.3)	$ 6.3	$ 7.1	$ (1.8)	$ (6.4)	$ 5.1	$ 3.5		$ (0.2)	$ (0.4)	$ (0.8)	$ (11.8)	$ (13.7)	$ 18.0	$ 13.3	$ 7.5	$ 7.5	$ (10.6)	$ (10.5)	$ (10.8)	$ (20.4)	$ 16.4	$ 10.6	$ 6.6	$ 6.1	$ (48.3)	$ (41.0)	$ (4.2)	$ (3.5)	$ 10.1	$ 10.1