Restatement and Amendment of Previously Reported Financial Information Summary of Error Correction, Equity (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended			3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended																					6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2012 As previously reported	Jun. 30, 2012 As previously reported	Jun. 30, 2012 Adjusted prior to the retrospective adoption	Jun. 30, 2012 Retrospective Adoption	Jun. 30, 2012 As restated and amended	Jun. 30, 2012 As restated and amended	Jun. 30, 2012 Corrections of Errors	Jun. 30, 2012 Corrections of Errors	Jun. 30, 2012 COMMON STOCK: As previously reported	Dec. 31, 2011 COMMON STOCK: As previously reported	Jun. 30, 2012 COMMON STOCK: Adjusted prior to the retrospective adoption	Dec. 31, 2011 COMMON STOCK: Adjusted prior to the retrospective adoption	Jun. 30, 2012 COMMON STOCK: Retrospective Adoption	Dec. 31, 2011 COMMON STOCK: Retrospective Adoption	Jun. 30, 2012 COMMON STOCK: As restated and amended	Dec. 31, 2011 COMMON STOCK: As restated and amended	Jun. 30, 2012 COMMON STOCK: Corrections of Errors	Dec. 31, 2011 COMMON STOCK: Corrections of Errors	Jun. 30, 2012 ADDITIONAL PAID-IN CAPITAL: As previously reported	Dec. 31, 2011 ADDITIONAL PAID-IN CAPITAL: As previously reported	Jun. 30, 2012 ADDITIONAL PAID-IN CAPITAL: Adjusted prior to the retrospective adoption	Dec. 31, 2011 ADDITIONAL PAID-IN CAPITAL: Adjusted prior to the retrospective adoption	Jun. 30, 2012 ADDITIONAL PAID-IN CAPITAL: Retrospective Adoption	Dec. 31, 2011 ADDITIONAL PAID-IN CAPITAL: Retrospective Adoption	Jun. 30, 2012 ADDITIONAL PAID-IN CAPITAL: As restated and amended	Dec. 31, 2011 ADDITIONAL PAID-IN CAPITAL: As restated and amended	Jun. 30, 2012 ADDITIONAL PAID-IN CAPITAL: Corrections of Errors	Dec. 31, 2011 ADDITIONAL PAID-IN CAPITAL: Corrections of Errors	Jun. 30, 2013 ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS):	Jun. 30, 2012 ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS):		Jun. 30, 2012 ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS): As previously reported	Jun. 30, 2012 ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS): Adjusted prior to the retrospective adoption	Jun. 30, 2012 ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS): Retrospective Adoption	Jun. 30, 2012 ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS): As restated and amended	Jun. 30, 2012 ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS): Corrections of Errors	Jun. 30, 2013 RETAINED EARNINGS (ACCUMULATED DEFICIT):	Jun. 30, 2012 RETAINED EARNINGS (ACCUMULATED DEFICIT):		Jun. 30, 2012 RETAINED EARNINGS (ACCUMULATED DEFICIT): As previously reported	Jun. 30, 2012 RETAINED EARNINGS (ACCUMULATED DEFICIT): Adjusted prior to the retrospective adoption	Jun. 30, 2012 RETAINED EARNINGS (ACCUMULATED DEFICIT): Retrospective Adoption	Jun. 30, 2012 RETAINED EARNINGS (ACCUMULATED DEFICIT): As restated and amended	Jun. 30, 2012 RETAINED EARNINGS (ACCUMULATED DEFICIT): Corrections of Errors
Balance, beginning of period						$ 645.8	$ 460.1	$ (36.1)		$ 424.0		$ (185.7)	$ 2.5	$ 2.5	$ 2.5	$ 2.5	$ 0	$ 0	$ 2.5	$ 2.5	$ 0	$ 0	$ 802.2	$ 802.2	$ 802.2	$ 802.2	$ 0	$ 0	$ 802.2	$ 802.2	$ 0	$ 0				$ 6.2	$ 6.4	$ (3.8)	$ 2.6	$ 0.2				$ (165.1)	$ (351.0)	$ (32.3)	$ (383.3)	$ (185.9)
Other comprehensive income (loss)	0	1.8	(16.0)	6.7	17.7	25.3			1.8	6.7	(15.9)	(18.6)																					(16.0)	6.7	[1]	25.3	6.7	0	6.7	(18.6)
Net income (loss)	4.6	(32.1)	(15.8)	(54.6)	(6.0)	(3.1)			(32.1)	(54.6)	(26.1)	(51.5)																													(15.8)	(54.6)	[1]	(3.1)	(54.6)	0	(54.6)	(51.5)
Change in stockholder’s equity						22.2	(47.9)	0		(47.9)		(70.1)
Balance, end of period					$ 668.0	$ 668.0	$ 412.2	$ (36.1)	$ 376.1	$ 376.1	$ (255.8)	$ (255.8)	$ 2.5	$ 2.5	$ 2.5	$ 2.5	$ 0	$ 0	$ 2.5	$ 2.5	$ 0	$ 0	$ 802.2	$ 802.2	$ 802.2	$ 802.2	$ 0	$ 0	$ 802.2	$ 802.2	$ 0	$ 0				$ 31.5	$ 13.1	$ (3.8)	$ 9.3	$ (18.4)				$ (168.2)	$ (405.6)	$ (32.3)	$ (437.9)	$ (237.4)

[1] Amounts reflect the cumulative impact of the retrospective adoption of amended guidance to ASC 944, Financial Services Insurance (ASU 2010-26), as detailed more fully within Note 2 to these financial statements.