Subsequent Event (Details) (Subsequent event, General Partner, USD $)	0 Months Ended
Jul. 23, 2013
Subsequent Events
Quarterly cash distribution declared (in dollars per unit)	$ 0.5875
Annualized basis
Subsequent Events
Quarterly cash distribution declared (in dollars per unit)	$ 2.35

Per-share or per-unit cash distributions declared to a common shareholder or unit-holder by an LLC or LP.

No definition available.

Name:	us-gaap_DistributionMadeToMemberOrLimitedPartnerDistributionsDeclaredPerUnit
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration