Multiemployer Pension Plans (Details) In Millions, unless otherwise specified	Sep. 30, 2012 American Maritime Officers Pension Plan [Member] USD ($)	Jun. 30, 2013 United Kingdom Merchant Navy Officers Pension Fund [Member] USD ($)	Jun. 30, 2013 United Kingdom Merchant Navy Officers Pension Fund [Member] GBP (£)
Defined Benefit Plan Disclosure [Line Items]
Pension and other postretirement benefit plans, withdrawal liability	$ 45.6
Pension And Other Postretirement Benefit Plans, Total Funding Deficit		182.6	120.0
Pension and Other Postretirement Benefit Plans, Allocated Share of Funding Deficit		$ 2.7	£ 1.8

Amount of the obligation recognized by withdrawing from a pension or postretirement benefit plan to which two or more unrelated employers contribute where assets contributed by one participating employer may be used to provide benefits to employees of other participating employers.

No definition available.

Name:	us-gaap_MultiemployerPlansWithdrawalObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant