Borrowings (Schedule Of Senior Unsecured Notes) (Details) - Senior Notes - USD ($)	Dec. 31, 2017	Sep. 15, 2017	Apr. 18, 2017	Apr. 04, 2017
Debt Instrument [Line Items]
Rate (%)	4.793%
Par Value	$ 3,718,600,000.0
February 1, 2019
Debt Instrument [Line Items]
Rate (%)	5.50%	5.50%	5.50%	5.50%
Par Value	$ 383,000,000
February 1, 2019
Debt Instrument [Line Items]
Rate (%)	3.875%
Par Value	$ 1,000,000,000
May 1, 2020
Debt Instrument [Line Items]
Rate (%)	5.375%	5.375%		5.375%
Par Value	$ 435,600,000.0
August 1, 2022
Debt Instrument [Line Items]
Rate (%)	5.00%	5.00%		5.00%
Par Value	$ 1,150,000,000
August 1, 2023
Debt Instrument [Line Items]
Rate (%)	5.00%
Par Value	$ 750,000,000