Basis of Presentation and Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013
Accounting Policies [Abstract]
Income related to out of period adjustments	$ 3.2

The portion of profit or loss for the period which is attributable to the parent.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.20)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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