Fair Value Measurements (Fair Value Of Notes Receivable And Notes Payable) (Details) - USD ($) $ in Millions		Jun. 30, 2015		Dec. 31, 2014		Jun. 30, 2014
Carrying Value		$ 2,674.7		$ 2,743.5
Fixed rate notes payable
Carrying Value		2,283.8		2,533.8
Estimated Fair Value		2,367.1		2,666.1
Floating rate notes payable (1)
Carrying Value		390.9	[1]	209.7	[1]	$ 390.5
Estimated Fair Value	[1]	$ 383.5		$ 203.7

[1] Includes balances outstanding under our unsecured line of credit and unsecured short term borrowings.