Fair Value Of Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Commitments Investments In Affiliated And Unaffiliated Partnerships	$ 11.4	$ 11.5
General and limited partnership interests in investment partnerships	52.5	42.1
Direct investments in private equity companies held by private equity funds	17.4	$ 21.2
Fair Value Level Two To Level One Transfers Amount	3.5
Fair Value Level One To Level Two Transfers Amount	9.6
Transfers, Into Level 3, Assets	1.3
Transfers, Out of Level 3, Assets	$ 6.3
Stated interest rate	5.375%
Maturity date	Dec. 31, 2022