Schedule II - Condensed Financial Information of Registrant Statements of Income (details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:
Investment income from subsidiaries									$ 318.7	$ 336.5	$ 364.6
Total revenues	1,331.6	1,379.5	1,461.5	1,269.9	1,283.2	1,304.8	1,223.9	1,158.0	5,442.7	4,970.1	4,645.5
Expenses:
Federal income taxes (credits)									225.0	(59.8)	(96.1)
Net Income (Loss)	94.7	102.9	193.9	56.2	(20.2)	(14.8)	(34.0)	0.4	447.8	(68.6)	(140.5)
Parent Company [Member]
Revenues:
Investment income from subsidiaries									38.1	39.9	40.1
Real estate and other income									4.4	4.4	4.1
Other investment income									0.8	0.5	0.6
Total revenues									43.3	44.9	44.9
Expenses:
Interest - subsidiaries									1.3	0.5	0.6
Interest - other									23.1	33.8	47.6
Real estate and other expenses									4.3	3.8	3.8
General expenses, taxes and fees									11.6	11.2	12.3
Total expenses									40.5	49.4	64.5
Revenues, net of expenses									2.7	(4.4)	(19.5)
Federal income taxes (credits)									0.3	(3.3)	(7.2)
Income (loss) before equity in earnings (losses) of subsidiaries									2.4	(1.0)	(12.2)
Dividends received									205.3	211.5	177.1
Earnings (losses) in excess of dividends									240.1	(279.1)	(305.3)
Net Income (Loss)									$ 447.8	$ (68.6)	$ (140.5)