9. Derivative Instruments (Details 1) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011 As restated and amended [Member]	Dec. 31, 2010 As restated and amended [Member]	Dec. 31, 2012 Interest rate swaps [Member]	Dec. 31, 2011 Interest rate swaps [Member] As restated and amended [Member]	Dec. 31, 2010 Interest rate swaps [Member] As restated and amended [Member]	Dec. 31, 2012 Variance Swaps [member]	Dec. 31, 2011 Variance Swaps [member] As restated and amended [Member]	Dec. 31, 2010 Variance Swaps [member] As restated and amended [Member]	Dec. 31, 2012 Swaptions [Member]	Dec. 31, 2011 Swaptions [Member] As restated and amended [Member]	Dec. 31, 2010 Swaptions [Member] As restated and amended [Member]	Dec. 31, 2012 Put options [Member]	Dec. 31, 2011 Put options [Member] As restated and amended [Member]	Dec. 31, 2010 Put options [Member] As restated and amended [Member]	Dec. 31, 2012 Call options [Member]	Dec. 31, 2011 Call options [Member] As restated and amended [Member]	Dec. 31, 2010 Call options [Member] As restated and amended [Member]	Dec. 31, 2012 Equity futures	Dec. 31, 2011 Equity futures As restated and amended [Member]	Dec. 31, 2010 Equity futures As restated and amended [Member]	Dec. 31, 2012 Embedded Derivatives [Member]	Dec. 31, 2011 Embedded Derivatives [Member] As restated and amended [Member]	Dec. 31, 2010 Embedded Derivatives [Member] As restated and amended [Member]	Dec. 31, 2012 Inter-company Reinsurance Derivatives [Member]	Dec. 31, 2011 Inter-company Reinsurance Derivatives [Member] As restated and amended [Member]	Dec. 31, 2010 Inter-company Reinsurance Derivatives [Member] As restated and amended [Member]
Total derivative instrument realized losses recognized in realized investment losses	$ (41.3)	$ (18.0)	$ (12.3)	$ (1.7)	$ 6.9	$ 0.5	$ (7.9)	$ 3.5	$ (0.6)	$ (0.2)	$ (0.8)	$ 1.0	$ (20.9)	$ 10.6	$ 2.7	$ 0.9	$ (8.9)	$ 8.3	$ (19.2)	$ (5.1)	$ (34.7)	$ 11.2	$ (33.2)	$ 12.2	$ (3.5)	$ 9.0	$ (1.7)