Debt Short-term and Long-term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Senior Notes	$ 210,000	$ 210,000
Convertible Debt	57,500	57,500
Line of Credit Facility, Amount Outstanding	73,500	59,200
Other Long-term Debt	859	1,257
Long-term Debt, Gross	341,859	327,957
Long-term Debt, Unclassified [Abstract]
Less: unamortized discount	(15,176)	(17,843)
Less: current portion	(617)	(737)
Total long-term portion	326,066	309,377
Long-term Debt	$ 326,683	$ 310,114