Hedging - Hedge Portfolio Table (Details)	Mar. 31, 2014 Average rate forward, settlement period - 2015 Derivatives designated as hedging instruments Average rate forward contracts USD ($)	Mar. 31, 2014 Average rate forward, settlement period - 2015 Derivatives designated as hedging instruments Average rate forward contracts EUR (€)	Mar. 31, 2014 Average rate forward, settlement period - 2014 Derivatives designated as hedging instruments Average rate forward contracts USD ($)	Mar. 31, 2014 Average rate forward, settlement period - 2014 Derivatives designated as hedging instruments Average rate forward contracts EUR (€)	Mar. 31, 2014 Commodity forward contract, settlement period - 2014 Derivatives designated as hedging instruments Bunker fuel forward contracts Mg		Mar. 31, 2014 Commodity forward contract, settlement period - 2015 Derivatives designated as hedging instruments Bunker fuel forward contracts Mg	Mar. 31, 2014 30-day euro forward contracts Derivatives not designated as hedging instruments 30-day euro forward contracts, settlement period - October 2013 USD ($)	Mar. 31, 2014 30-day euro forward contracts Derivatives not designated as hedging instruments 30-day euro forward contracts, settlement period - October 2013 EUR (€)	Mar. 31, 2013 Purchased Foreign exchange option, settlement period - 2014 Euro put option EUR (€)	Mar. 31, 2014 Purchased Foreign exchange option, settlement period - 2014 Derivatives designated as hedging instruments Euro put option USD ($)	Mar. 31, 2014 Purchased Foreign exchange option, settlement period - 2014 Derivatives designated as hedging instruments Euro put option EUR (€)	Mar. 31, 2013 Purchased Foreign exchange option, settlement period - 2015 Euro put option EUR (€)	Mar. 31, 2014 Purchased Foreign exchange option, settlement period - 2015 Derivatives designated as hedging instruments Euro put option USD ($)	Mar. 31, 2014 Purchased Foreign exchange option, settlement period - 2015 Derivatives designated as hedging instruments Euro put option EUR (€)	Mar. 31, 2013 Sold Foreign exchange option, settlement period - 2014 Euro call option EUR (€)	Mar. 31, 2014 Sold Foreign exchange option, settlement period - 2014 Derivatives designated as hedging instruments Euro call option USD ($)	Mar. 31, 2014 Sold Foreign exchange option, settlement period - 2014 Derivatives designated as hedging instruments Euro call option EUR (€)	Mar. 31, 2013 Sold Foreign exchange option, settlement period - 2015 Euro call option EUR (€)	Mar. 31, 2014 Sold Foreign exchange option, settlement period - 2015 Derivatives designated as hedging instruments Euro call option USD ($)	Mar. 31, 2014 Sold Foreign exchange option, settlement period - 2015 Derivatives designated as hedging instruments Euro call option EUR (€)
Derivative [Line Items]
Currency derivatives - Notional Amount		€ 14,000,000		€ 118,000,000					€ 52,000,000	€ 25,000,000		€ 131,000,000	€ 19,000,000		€ 113,000,000	€ 25,000,000		€ 131,000,000	€ 19,000,000		€ 113,000,000
Fuel derivatives - Notional Amount					66,885	[1]	59,800
Currency derivatives - Contract Average Rate/Price (in $ per EUR)	1.38		1.36					1.37			1.33			1.36			1.39			1.40
Fuel derivatives - Contract Average Rate/Price (in $ per mt)					586	[1]	556

[1] Settlement periods for bunker fuel forward contracts and currency derivatives are through September 2015 and June 2015, respectively.