Hedging - Cash Flow Hedging Instruments (Details) - Cash flow hedging instruments - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivative (effective portion)		$ (2,270)	$ 4,441	$ 16,004	$ 3,395
Gain (loss) reclassified from accumulated OCI into income (effective portion)	[1]	10,364	(959)	18,567	(1,811)
Gain (loss) recognized in income on derivative (ineffective portion)	[1]	18	(107)	67	(428)
Currency Hedge Portfolio
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivative (effective portion)		(3,296)	2,694	15,131	2,774
Gain (loss) reclassified from accumulated OCI into income (effective portion)	[1]	13,829	(1,020)	30,807	(2,047)
Gain (loss) recognized in income on derivative (ineffective portion)	[1]	0	0	0	0
Bunker Fuel Forward Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivative (effective portion)		1,026	1,747	873	621
Gain (loss) reclassified from accumulated OCI into income (effective portion)	[1]	(3,465)	61	(12,240)	236
Gain (loss) recognized in income on derivative (ineffective portion)	[1]	$ 18	$ (107)	$ 67	$ (428)

[1] Both the gain (loss) reclassified from "AOCI" 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.