Securities Sold Under Agreements To Repurchase (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]
Securities sold under agreements to repurchase average	$ 321.1	$ 189.5	$ 177.9
Securities sold under agreements to repurchase maximum outstanding	$ 334.6	$ 313.3	$ 233.8