Basis of Presentation and Principles of Consolidation (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014
Basis of Presentation and Principles of Consolidation
Borrowings under commercial paper program, net	$ 266.9	$ 0.0

The net cash inflow or cash outflow from issuing (borrowing) and repaying commercial paper.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 9

-Subparagraph c

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3098-108585

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