Hedging - Cash Flow Hedging Instruments (Details) (Cash flow hedging instruments, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivative (effective portion)	$ (1,046)		$ 9,062
Gain (loss) reclassified from accumulated OCI into income (effective portion)	(852)	[1]	(5,793)	[1]
Gain (loss) recognized in income on derivative (ineffective portion)	(321)	[1]	(610)	[1]
Currency Hedge Portfolio
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivative (effective portion)	80		6,564
Gain (loss) reclassified from accumulated OCI into income (effective portion)	(1,027)	[1]	(8,632)	[1]
Gain (loss) recognized in income on derivative (ineffective portion)	0	[1]	0	[1]
Bunker Fuel Forward Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivative (effective portion)	(1,126)		2,498
Gain (loss) reclassified from accumulated OCI into income (effective portion)	175	[1]	2,839	[1]
Gain (loss) recognized in income on derivative (ineffective portion)	$ (321)	[1]	$ (610)	[1]

[1] Both the gain (loss) reclassified from accumulated OCI into income (effective portion) and the gain (loss) recognized in income on derivative (ineffective portion, if any) are included in "Net sales" for the currency hedge portfolio and "Cost of sales" for bunker fuel forward contracts.