Debt (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Long-term debt
Carrying value of debt	$ 267,423	$ 274,698
Current portion of long-term debt	(15,000)	(15,000)
Total long-term debt, net	252,423	259,698
Senior Subordinated Convertible Notes 2010
Long-term debt
Carrying value of debt	128,673	124,698
2012 Credit Agreement | Term Loan
Long-term debt
Carrying value of debt	138,750	150,000
2012 Credit Agreement | Revolving Credit Facility
Long-term debt
Carrying value of debt