Long-Term Debt Components of Convertible Debt (Details) (Convertible Subordinated Debt [Member], Convertible Senior Subordinated Debentures February 2027 [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Convertible Subordinated Debt [Member] | Convertible Senior Subordinated Debentures February 2027 [Member]
Debt Instrument [Line Items]
Principal amount of liability component	$ 13,350	$ 13,350
Debt Instrument, Unamortized Discount	(3,190)	(3,341)
Convertible Debt	$ 10,160	$ 10,009