Investments in Unconsolidated Affiliates (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Investments in unconsolidated affiliates
Total investments in unconsolidated affiliates	$ 373.3	$ 321.4
Symetra
Investments in unconsolidated affiliates
Equity in Unrealized Gains (Losses) from Investments in Unconsolidated Affiliates	(4.2)	(43.6)
Total investments in unconsolidated affiliates	369.0	317.3	377.5	381.5
Symetra | Common shareholders' equity.
Investments in unconsolidated affiliates
Symetra Common Shares excluding unrealized gains (losses)	373.2	360.9
Total investments in unconsolidated affiliates	369.0	317.3	350.9	351.2
Symetra | Warrants
Investments in unconsolidated affiliates
Total investments in unconsolidated affiliates	0	0	26.6	30.3
Hamer, LLC
Investments in unconsolidated affiliates
Total investments in unconsolidated affiliates	$ 4.3	$ 4.1