Interest Expense (Interest Expense Schedule) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Interest Expense [Abstract]
Contractual interest on Convertible Debentures	$ 10,156	$ 10,156
Contractual interest on Notes	8,672	0
Interest capitalized to Property and equipment, net	(216)	(268)
Amortization of debt discount on the Convertible Debentures	2,282	2,101
Credit facility and other interest expense	491	607
Total interest expense	$ 21,385	$ 12,596