Condensed Consolidated Statements Of Cash Flows Footnote (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016		Mar. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Cash and Cash Equivalents, at Carrying Value, Including Discontinued Operations		$ 590,409	[1]		$ 262,644
Cash and cash equivalents	$ 346,221	$ 577,658		$ 324,636	$ 262,644

[1] (1)Cash and cash equivalents at the beginning of the three months ended March 31, 2017 of $590 million are comprised of $578 million of cash and cash equivalents from continuing operations as reflected in the Company’s unaudited Condensed Consolidated Balance Sheets and $13 million of cash and cash equivalents reflected in current assets of discontinued operations, as further described in Note 2.