Subsequent Events (Details) (Subsequent Event [Member], Cash Distribution [Member], USD $) In Millions, except Per Share data, unless otherwise specified	1 Months Ended
Jul. 31, 2012
Subsequent Event [Member] \| Cash Distribution [Member]
Subsequent Event [Line Items]
Distribution Made to Member or Limited Partner, Distributions Declared, Per Unit	$ 0.52
Distribution Made to Member or Limited Partner, Cash Distributions Declared	$ 18.6

The equity impact of cash distributions declared to a common shareholder or unit-holder by a LLC or LP.

No definition available.

Name:	us-gaap_DistributionMadeToMemberOrLimitedPartnerCashDistributionsDeclared
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration