Acquisitions (Schedule Of Recognized Identified Assets Acquired And Liabilities Assumed) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Business Acquisition [Line Items]
Property and equipment	$ 176,300
Intangible assets	$ 351,000
Oi. S. A. Acquisitions [Member]
Business Acquisition [Line Items]
Property and equipment		$ 99,810	$ 86,787
Intangible assets		363,352	587,111
Net assets acquired		$ 463,162	$ 673,898