Acquisitions (Fair Value Of Total Consideration Transferred And Major Class Of Consideration) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014	Mar. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 3,500,668		$ 3,381,149
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Accounts receivable	11,355	[1]		417
Other current assets	4,091	[1]		81
Property and equipment	3,465	[1]		429
Goodwill	117,141	[1]		8,260
Intangible assets	44,663	[1]		0
Other long-term assets	35	[1]		0
Accounts payable	(1,023)	[1]		(125)
Other accrued liabilities	(6,774)	[1]		(39)
Deferred income taxes	(12,190)	[1]		0
Other long-term liabilities	(4,301)	[1]		0
Long-term debt	(735)	[1]		0
Total fair value	155,727	[1]		9,023
Less: Fair value attributable to noncontrolling interests	23,649	[1]		3,985
Acquisition date fair value of total consideration transferred	$ 132,078	[1]		$ 5,038

[1] Represents the preliminary allocation of fair value of acquired assets and liabilities associated with these acquisitions at March 31, 2015.