Interest Expense (Interest Expense Schedule) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Interest Expense [Abstract]
Contractual interest on Convertible Debentures	$ 10,156	$ 10,156	$ 30,469	$ 30,469
Contractual interest on Notes	8,672	8,672	26,015	15,899
Amortization of debt discount on the Convertible Debentures	2,375	2,189	6,986	6,435
Credit facility and other interest expense	497	443	1,482	1,623
Interest capitalized to Property and equipment, net	(167)	(341)	(544)	(902)
Total interest expense	$ 21,533	$ 21,119	$ 64,408	$ 53,524