Segment Reporting Segment Reporting - Additional Information (Details)	12 Months Ended
Dec. 31, 2014 business_segments
Segment Reporting [Abstract]
Number of Reportable Segments	4us-gaap_NumberOfReportableSegments
Description of Effect on Previously Reported Segment Information for Change in Composition of Reportable Segments	1

Disclosure about a restatement of previous periods' segment information resulting from a change in the composition of the entity's reportable segments.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 280

-SubTopic 10

-Section 50

-Paragraph 34

-URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8981-108599

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 280

-SubTopic 10

-Section 50

-Paragraph 35

-URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8984-108599

Name:	us-gaap_DescriptionOfEffectOnPreviouslyReportedSegmentInformationForChangeInCompositionOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration