Short-term and Long-term Debt (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
LONG-TERM DEBT
Senior Notes	$ 210,000us-gaap_SeniorNotes	$ 210,000us-gaap_SeniorNotes
Convertible Debt	57,500us-gaap_ConvertibleDebt	57,500us-gaap_ConvertibleDebt
Long-term Line of Credit	59,200us-gaap_LineOfCredit	0us-gaap_LineOfCredit
Other Long-term Debt	1,257us-gaap_OtherLongTermDebt	998us-gaap_OtherLongTermDebt
Long-term Debt, Gross	327,957us-gaap_DebtInstrumentCarryingAmount	268,498us-gaap_DebtInstrumentCarryingAmount
Less: unamortized discount	(17,843)	(22,502)
Current portion of long-term debt	(737)	(397)
Total long-term portion	309,377us-gaap_LongTermDebtNoncurrent	245,599us-gaap_LongTermDebtNoncurrent
Long-term Debt	$ 310,114us-gaap_LongTermDebt	$ 245,996us-gaap_LongTermDebt

Including the current and noncurrent portions, carrying amount of debt identified as being convertible into another form of financial instrument (typically the entity's common stock) as of the balance sheet date, which originally required full repayment more than twelve months after issuance or greater than the normal operating cycle of the company.

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Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

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The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt and capital leases due within one year or the normal operating cycle, if longer.

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Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Including both current and noncurrent portions, carrying amount as of the balance sheet date of other forms of debt not elsewhere specified in the taxonomy with initial maturities beyond one year or beyond the normal operating cycle, if longer.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

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