Fair Value Measurements Narrative (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value of senior secured notes	$ 234,675
Carrying value of senior secured notes	205,033
Estimated fair value of convertible notes	90,991
Carrying value of convertible notes	39,965
Carrying value of the line of credit	0
Forward Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Notional Amount	12,492	17,191
Gain (Losses) as a result of changes in the fair value of the contracts	(2,141)	(430)	(2,377)
Derivative Asset, Fair Value, Gross Asset	$ 0	$ 19