Derivative Instruments and Hedging Activities (Details) (USD $)	3 Months Ended		6 Months Ended																									3 Months Ended																				3 Months Ended	6 Months Ended							3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Effective in 2015 [Member]	Jun. 30, 2014 Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2013 Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member]	Jun. 30, 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]	Jun. 30, 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]	Jun. 30, 2014 Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member]	Jun. 30, 2014 Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Jun. 30, 2014 Swap [Member] Derivatives Not Designated as Hedging Instruments [Member]	Dec. 31, 2013 Swap [Member] Derivatives Not Designated as Hedging Instruments [Member]	Jun. 30, 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]	Jun. 30, 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]	Jun. 30, 2014 Swap [Member] Derivatives Designated as Hedging Instruments [Member]	Dec. 31, 2013 Swap [Member] Derivatives Designated as Hedging Instruments [Member]	Jun. 30, 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]	Jun. 30, 2014 Interest Rate Swap Agreements [Member]	Jun. 30, 2014 Interest Rate Swap Agreements [Member] Effective in 2014 [Member]	Jun. 30, 2014 Interest Rate Swap Agreements [Member] Derivatives Designated as Hedging Instruments [Member]	Jun. 30, 2014 Interest Rate Swap Agreements [Member] Swap [Member] Derivatives Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Jun. 30, 2014 Interest Rate Swap Agreements [Member] Swap [Member] Derivatives Designated as Hedging Instruments [Member] Other Long-Term Liabilities [Member]	Dec. 31, 2013 Foreign Currency Exchange Contracts [Member] Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member]	Jun. 30, 2014 Foreign Currency Exchange Contracts [Member] Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Dec. 31, 2013 Foreign Currency Exchange Contracts [Member] Forward Contracts [Member] Derivatives Not Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Dec. 31, 2013 Foreign Currency Exchange Contracts [Member] Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member]	Dec. 31, 2013 Foreign Currency Exchange Contracts [Member] Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member] Accrued Liabilities [Member]	Jun. 30, 2014 Foreign Currency Exchange Contracts [Member] Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member] Other Long-Term Liabilities [Member]	Dec. 31, 2013 Foreign Currency Exchange Contracts [Member] Forward Contracts [Member] Derivatives Designated as Hedging Instruments [Member] Other Long-Term Liabilities [Member]	Jun. 30, 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]	Jun. 30, 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]	Jun. 30, 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]	Jun. 30, 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]	Jun. 30, 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]	Jun. 30, 2014 Cash Convertible Notes Hedge [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2014 Cash Convertible Notes Hedge [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 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]	Jun. 30, 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]	Jun. 30, 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]	Jun. 30, 2014 Cash Conversion Derivative [Member] Selling, General and Administrative Expenses [Member]	Jun. 30, 2014 Cash Conversion Derivative [Member] Selling, General and Administrative Expenses [Member]
Derivatives, Fair Value [Line Items]
Current notional amount at 06/30/14																										$ 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%		0.69%
Higher variable interest rate range (in hundredths)	1.48%		1.48%
Fair Values of Derivative Instruments [Abstract]
Assets						56,000	178,000	56,000	178,000	0	0			0	0	0	0		0	0																														37,346,000	27,766,000	0	0	37,346,000	27,766,000
Liabilities						0						227,000	0	0	0			0			583,000	505,000	0	0	505,000				0	583,000	0	227,000	67,000	67,000	0	0	0	37,346,000	27,766,000	0	0	37,346,000	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		400,000
Derivatives in Cash Flow Hedging Relationships [Abstract]
Loss related to effective portion of derivatives recognized in accumulated OCI, gross of tax effect	216,000	(754,000)	281,000	(696,000)
Loss related to effective portion of derivatives reclassified from accumulated OCI to interest expense, gross of tax effect	130,000	551,000	256,000	1,180,000
Gains or losses on cash flow hedges recognized in our consolidated statements of comprehensive income (loss) resulting from hedge ineffectiveness			0	0																																												1,849,000	9,580,000							(1,849,000)	(9,580,000)
Notional amount of foreign currency exchange contracts	$ 20,900,000		$ 20,900,000