Basis of Presentation and Principles of Consolidation (Details) $ in Millions	6 Months Ended
Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)
Basis of Presentation and Principles of Consolidation
Stock split, conversion ratio	2
Borrowings under commercial paper program, net	$ 172.5	$ 0.0

Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 4

-Subparagraph (SAB TOPIC 4.C)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Stock Split

-URI http://asc.fasb.org/extlink&oid=6525746

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