Equity (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Comprehensive Income Net Of Tax [Line Items]
Balance at beginning of year	$ 71,959	$ 4,649	$ 3,128
Other Comprehensive Income Before Reclassifications	(56,028)	(64,704)	(2,148)
Amounts Reclassified From AOCI	(1,089)	(2,606)	627
Net change in accumulated other comprehensive income	(57,117)	(67,310)	(1,521)
Balance at end of period	14,842	71,959	4,649
Provision for income taxes	15,478	2,041	(15,505)
Foreigh currency translation gain (loss), net of tax
Comprehensive Income Net Of Tax [Line Items]
Balance at beginning of year	0	4,649	2,874
Other Comprehensive Income Before Reclassifications	0	(7,255)	(1,775)
Amounts Reclassified From AOCI	0	2,606	0
Net change in accumulated other comprehensive income	0	(4,649)	(1,775)
Balance at end of period	0	0	4,649
Marketable securities, net of tax
Comprehensive Income Net Of Tax [Line Items]
Balance at beginning of year	71,959	0	254
Other Comprehensive Income Before Reclassifications	(56,028)	(71,959)	(373)
Amounts Reclassified From AOCI	(1,089)	0	627
Net change in accumulated other comprehensive income	(57,117)	(71,959)	254
Balance at end of period	$ 14,842	$ 71,959	$ 0