Consolidated Statements of Comprehensive Income Statement (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Other Comprehensive Income [Abstract]
Net Income (Loss) As Reported	$ 447.8	$ (68.6)	$ (140.5)
Unrealized gains (loses) on securities before reclassifications	(107.0)	161.3	126.6
Amounts reclassified as realized investment gains from sales in the statements of income	(148.1)	(47.8)	(115.5)
Pretax unrealized gains (losses) on securities	(255.2)	113.4	11.1
Deferred income taxes (credits)	(89.0)	39.5	3.5
Net unrealized gains (losses) on securities, net of tax	(166.2)	73.8	7.5
Net pension adjustment before reclassifications	104.7	(29.9)	(61.8)
Amounts reclassified as underwriting, acquisition, and other expenses in the statements of income	7.0	10.4	5.9
Net adjustment related to defined benefit pension plans	111.7	(19.4)	(55.8)
Deferred income taxes (credits)	39.1	(6.8)	(19.5)
Net adjustment related to defined benefit pension plans, net of tax	72.6	(12.6)	(36.2)
Foreign currency translation and other adjustments	(9.9)	4.4	(14.3)
Net adjustments	(103.5)	65.6	(43.0)
Comprehensive Income (Loss)	$ 344.3	$ (3.0)	$ (183.5)