Securities Sold Under Agreements To Repurchase (Narrative) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Securities Sold Under Agreements To Repurchase [Abstract]
Securities sold under agreements to repurchase average	$ 142.4	$ 113.1	$ 54.7
Securities sold under agreements to repurchase maximum outstanding	$ 166.3	$ 148.2	$ 73.8