Reinsurance - Other Reinsurance Activity (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Direct Business and Reinsurance:
Direct premiums	$ 19.8	$ 18.5
Premiums ceded to non-affiliate reinsurers	(16.7)	(17.8)
Premiums	3.1	0.7
Direct policy benefits incurred	55.1	60.2
Policy benefits assumed from non-affiliate reinsureds	0	0
Policy benefits ceded to:
Affiliate reinsurers	0	(1.9)
Non-affiliate reinsurers	(19.6)	(33.5)
Policy benefits ceded to reinsurers	(19.6)	(35.4)
Premiums paid to:
Affiliate reinsurers	5.3	4.4
Non-affiliate reinsurers	2.9	14.0
Premiums paid to reinsurers	8.2	18.4
Policy benefits	43.7	43.2
Interest credited to policyholders and other items	$ 44.8	$ 18.6