Debt And Interest Expense (Components Of Interest Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Short-term Debt [Line Items]
Contractual interest on Convertible Debentures	$ 40,625	$ 40,625	$ 40,625
Interest Expense, Debt	54,667	34,688	24,570
Amortization of debt discount on the Convertible Debentures	10,218	9,412	8,670
Interest capitalized to property and equipment, net	(586)	(707)	(1,218)
Other interest expense	2,707	1,976	2,114
Total interest expense	$ 107,631	$ 85,994	$ 74,761