Mezzanine Equity (Sensitivity Analysis Of Fair Value Of Redeemable Noncontrolling Interests Using Discount And Terminal Growth Rates) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Terminal growth rate assumed in determining fair value	11.50%
Terminal growth rate used to calculate the capitalization rate	2.00%
Rate 1.75% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Terminal growth rate used to calculate the capitalization rate	1.75%
Rate 2.00% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Terminal growth rate used to calculate the capitalization rate	2.00%
Rate 2.25% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Terminal growth rate used to calculate the capitalization rate	2.25%
Rate 12.45% Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Terminal growth rate assumed in determining fair value	11.25%
Rate 12.45% Discount Rate [Member] | Rate 1.75% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 235.8
Rate 12.45% Discount Rate [Member] | Rate 2.00% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	239.5
Rate 12.45% Discount Rate [Member] | Rate 2.25% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 243.4
Rate 12.70% Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Terminal growth rate assumed in determining fair value	11.50%
Rate 12.70% Discount Rate [Member] | Rate 1.75% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 228.2
Rate 12.70% Discount Rate [Member] | Rate 2.00% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	231.6
Rate 12.70% Discount Rate [Member] | Rate 2.25% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 235.3
Rate 12.95% Discount Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Terminal growth rate assumed in determining fair value	11.75%
Rate 12.95% Discount Rate [Member] | Rate 1.75% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 221.0
Rate 12.95% Discount Rate [Member] | Rate 2.00% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	224.2
Rate 12.95% Discount Rate [Member] | Rate 2.25% Terminal Growth Rates [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of redeemable noncontrolling interests	$ 227.5