Goodwill And Other Intangible Assets (Schedule Of Change In Goodwill) (Details) - USD ($)		3 Months Ended	6 Months Ended
		Jun. 30, 2018	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Impairment of goodwill and intangible assets		$ 0
Goodwill [Roll Forward]
Balance at January 1, 2018			$ 1,614,494,000
Additions	[1]		47,944,000
Other			0
Balance at June 30, 2018		$ 1,662,438,000	$ 1,662,438,000

[1] Amount relates to preliminary purchase price allocation of goodwill associated with the 2018 Business Combination. See Note 5 for more information regarding the Company's acquisitions.