Hedging - Hedge Portfolio Table (Details)	Feb. 05, 2015 Euro put option USD ($)	Feb. 05, 2015 Bunker fuel forward contracts Mg	Mar. 31, 2015 Commodity forward contract, settlement period - 2015 Designated as Hedging Instrument [Member] Bunker fuel forward contracts Mg		Mar. 31, 2015 Purchased Foreign exchange option, settlement period - 2015 Designated as Hedging Instrument [Member] Euro put option USD ($)		Mar. 31, 2015 Purchased Foreign exchange option, settlement period - 2015 Designated as Hedging Instrument [Member] Euro put option EUR (€)		Mar. 31, 2015 Sold Foreign exchange option, settlement period - 2015 Designated as Hedging Instrument [Member] Euro call option USD ($)		Mar. 31, 2015 Sold Foreign exchange option, settlement period - 2015 Designated as Hedging Instrument [Member] Euro call option EUR (€)
Derivative [Line Items]
Currency derivatives - Notional Amount							€ 89,000,000	[1]			€ 89,000,000	[1]
Fuel derivatives - Notional Amount		17,460	27,520	[1]
Currency derivatives - Contract Average Rate/Price (in $ per EUR)	1.37				1.36	[1]			1.40	[1]
Bunker fuel forward contracts, contract average rate		562.92	554	[1]

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