Derivative Instruments and Hedging Activities (Details) (USD $)	3 Months Ended																											3 Months Ended																	3 Months Ended							3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Effective in 2015 [Member]	Mar. 31, 2014 Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2013 Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member]	Mar. 31, 2014 Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Current Assets [Member]	Dec. 31, 2013 Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Current Assets [Member]	Mar. 31, 2014 Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Noncurrent Assets [Member]	Dec. 31, 2013 Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Noncurrent Assets [Member]	Mar. 31, 2014 Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member]	Dec. 31, 2013 Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member]	Mar. 31, 2014 Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Dec. 31, 2013 Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Mar. 31, 2014 Swap [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2013 Swap [Member] Derivatives Not Designated as Hedging Instruments [Member]	Mar. 31, 2014 Swap [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Current Assets [Member]	Dec. 31, 2013 Swap [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Current Assets [Member]	Dec. 31, 2013 Swap [Member] Derivatives Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Mar. 31, 2014 Swap [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Noncurrent Assets [Member]	Dec. 31, 2013 Swap [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Noncurrent Assets [Member]	Mar. 31, 2014 Swap [Member] Derivatives Designated as Hedging Instruments [Member]	Dec. 31, 2013 Swap [Member] Derivatives Designated as Hedging Instruments [Member]	Mar. 31, 2014 Swap [Member] Derivatives Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Dec. 31, 2013 Swap [Member] Derivatives Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Dec. 31, 2013 Swap [Member] Derivatives Designated as Hedging Instruments [Member] Other Long-Term Liabilities [Member]	Mar. 31, 2014 Interest Rate Swap Agreements [Member]	Mar. 31, 2014 Interest Rate Swap Agreements [Member] Effective in 2014 [Member]	Mar. 31, 2014 Interest Rate Swap Agreements [Member] Derivatives Designated as Hedging Instruments [Member]	Dec. 31, 2013 Interest Rate Swap Agreements [Member] Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Dec. 31, 2013 Interest Rate Swap Agreements [Member] Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member] Other Long-Term Liabilities [Member]	Mar. 31, 2014 Interest Rate Swap Agreements [Member] Swap [Member] Derivatives Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Mar. 31, 2014 Interest Rate Swap Agreements [Member] Swap [Member] Derivatives Designated as Hedging Instruments [Member] Other Long-Term Liabilities [Member]	Mar. 31, 2014 Foreign Currency Exchange Contracts [Member] Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Mar. 31, 2014 Foreign Currency Exchange Contracts [Member] Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member] Other Long-Term Liabilities [Member]	Mar. 31, 2014 Embedded Derivative Financial Instruments [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2013 Embedded Derivative Financial Instruments [Member] Derivatives Not Designated as Hedging Instruments [Member]	Mar. 31, 2014 Embedded Derivative Financial Instruments [Member] Derivatives Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Dec. 31, 2013 Embedded Derivative Financial Instruments [Member] Derivatives Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Mar. 31, 2014 Embedded Derivative Financial Instruments [Member] Derivatives Designated as Hedging Instruments [Member]	Dec. 31, 2013 Embedded Derivative Financial Instruments [Member] Derivatives Designated as Hedging Instruments [Member]	Mar. 31, 2014 Embedded Derivative Financial Instruments [Member] Derivatives Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Dec. 31, 2013 Embedded Derivative Financial Instruments [Member] Derivatives Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Mar. 31, 2014 Embedded Derivative Financial Instruments [Member] Derivatives Designated as Hedging Instruments [Member] Other Long-Term Liabilities [Member]	Dec. 31, 2013 Embedded Derivative Financial Instruments [Member] Derivatives Designated as Hedging Instruments [Member] Other Long-Term Liabilities [Member]	Mar. 31, 2014 Cash Convertible Notes Hedge [Member] Selling, General and Administrative Expenses [Member]	Mar. 31, 2014 Cash Convertible Notes Hedge [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2013 Cash Convertible Notes Hedge [Member] Derivatives Not Designated as Hedging Instruments [Member]	Mar. 31, 2014 Cash Convertible Notes Hedge [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Current Assets [Member]	Dec. 31, 2013 Cash Convertible Notes Hedge [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Current Assets [Member]	Mar. 31, 2014 Cash Convertible Notes Hedge [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Noncurrent Assets [Member]	Dec. 31, 2013 Cash Convertible Notes Hedge [Member] Derivatives Not Designated as Hedging Instruments [Member] Other Noncurrent Assets [Member]	Mar. 31, 2014 Cash Conversion Derivative [Member] Selling, General and Administrative Expenses [Member]
Derivatives, Fair Value [Line Items]
Current notional amount at 03/31/14																										$ 145,000,000
Notional amount effective in future			50,000,000																								95,000,000
Description of variable rate basis																												LIBOR (as defined in Note 5)
Lower variable interest rate range (in hundredths)	0.69%
Higher variable interest rate range (in hundredths)	1.48%
Fair Values of Derivative Instruments [Abstract]
Assets				52,000	178,000	52,000	178,000	0	0					0	0	0	0		0	0																										35,497,000	27,766,000	0	0	35,497,000	27,766,000
Liabilities				0	0					159,000	67,000	0	0	0	0			0			471,000	505,000	0	0	505,000				67,000	0	0	471,000	159,000	0	35,497,000	27,766,000	0	0	35,497,000	27,766,000	0	0	0	0
Reclassification of net losses on interest rate swap agreements from accumulated OCI to interest expense within the next 12 months	400,000
Derivatives in Cash Flow Hedging Relationships [Abstract]
Loss related to effective portion of derivatives recognized in accumulated OCI, gross of tax effect	66,000	58,000
Loss related to effective portion of derivatives reclassified from accumulated OCI to interest expense, gross of tax effect	126,000	629,000
Gains or losses on cash flow hedges recognized in our consolidated statements of comprehensive income (loss) resulting from hedge ineffectiveness	0	0																																											7,731,000							(7,731,000)
Notional amount of foreign currency exchange contracts	$ 21,100,000