Income Taxes Allocation of Income Tax (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 10.4	$ (11.8)	$ 5.6	$ (0.4)	$ (7.1)	$ 1.2	$ (16.9)	$ (1.9)	$ 5.2	$ (18.8)	$ (6.6)	$ (17.6)	$ 3.8	$ (24.7)	$ 17.0
Income tax from OCI:
Applicable deferred income tax expense (benefit)													31.9	(11.6)	24.3
Income tax related to cumulative effect of change in accounting guidance													0	0	0
Total income tax recorded to all components of income													$ 35.7	$ (36.3)	$ 41.3