Subsequent Events (Details) (Subsequent event, Estimated, USD $) In Millions, unless otherwise specified	0 Months Ended
Jul. 31, 2013
Subsequent event \| Estimated
Subsequent Events
Gain on sale from interest in a joint venture	$ 5.4

This item represents the amount of gain (loss) arising from the disposal of an equity method investment.

No definition available.

Name:	us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration