13. Fair Value of Financial Instruments (Details 7) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Policy Loans [Member] | Level 3 [Member]
Carrying Amounts and Fair Values of Financial Instruments:
Carrying Value of Financial instruments	$ 2,338.4
Fair Value of Financial instruments	2,326.8
Policy Loans [Member] | Level 3 [Member] | As restated and amended [Member]
Carrying Amounts and Fair Values of Financial Instruments:
Carrying Value of Financial instruments		2,379.3
Fair Value of Financial instruments		2,367.7
Cash and Cash Equivalents [Member] | Level 1 [member]
Carrying Amounts and Fair Values of Financial Instruments:
Carrying Value of Financial instruments	283.8	168.2
Fair Value of Financial instruments	283.8	168.2
Investment Contracts [Member] | Level 3 [Member]
Carrying Amounts and Fair Values of Financial Instruments:
Carrying Value of Financial instruments	2,914.6
Fair Value of Financial instruments	2,920.2
Investment Contracts [Member] | Level 3 [Member] | As restated and amended [Member]
Carrying Amounts and Fair Values of Financial Instruments:
Carrying Value of Financial instruments		2,432.3
Fair Value of Financial instruments		2,443.5
Surplus notes [Member] | Level 3 [Member]
Carrying Amounts and Fair Values of Financial Instruments:
Carrying Value of Financial instruments	126.1
Fair Value of Financial instruments	95.0
Surplus notes [Member] | Level 3 [Member] | As restated and amended [Member]
Carrying Amounts and Fair Values of Financial Instruments:
Carrying Value of Financial instruments		174.2
Fair Value of Financial instruments		126.9
Senior unsecured bonds [Member] | Level 2 [Member]
Carrying Amounts and Fair Values of Financial Instruments:
Carrying Value of Financial instruments	252.7
Fair Value of Financial instruments	245.1
Senior unsecured bonds [Member] | Level 2 [Member] | As restated and amended [Member]
Carrying Amounts and Fair Values of Financial Instruments:
Carrying Value of Financial instruments		252.7
Fair Value of Financial instruments		$ 195.1