Income Taxes Narrative (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2013	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Income (loss) before income taxes	$ 81.2	$ (12.6)	$ (12.3)	$ (22.3)	$ (34.6)	$ (47.2)	$ 34.0	$ (121.5)	$ (26.3)
Valuation allowance	74.2						74.2	105.4
Deferred tax asset, net, before valuation allowance	102.2						102.2
Deferred tax assets on gross unrealized losses on available for sale debt securities	28.0						28.0
Impact of valuation allowance on net loss							31.7
Increase in OCI-related deferred tax balances								0.5
Net operating and capital loss carryover benefits	0						0	1.7
Alternative minimum tax credits	$ 2.1						$ 2.1	$ 1.8