Deferred Policy Acquisition Costs (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Deferred Policy Acquisition Costs:
Policy acquisition costs deferred	$ 66.7		$ 69.8		$ 100.7
Costs amortized to expenses:
Recurring costs	(80.3)		(102.6)		(108.1)
Assumption unlocking	1.6		(1.4)		(1.3)
Realized investment gains (losses)	(9.7)		0.5		(0.1)
Offsets to net unrealized investment gains or losses included in AOCI [1]	57.8	[1]	(29.2)	[1]	(37.4)	[1]
Change in deferred policy acquisition costs	36.1		(62.9)		(46.2)
Deferred policy acquisition costs, beginning of period	426.2		489.1		535.3
Deferred policy acquisition costs, end of period	$ 462.3		$ 426.2		$ 489.1

[1] An offset to deferred policy acquisition costs and AOCI is recorded each period to the extent that, had unrealized holding gains or losses from securities classified as available-for-sale actually been realized, an adjustment to deferred policy acquisition costs amortized using gross profits or gross margins would result.