Fair Value Measurements (Details) - Recurring basis - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Fair value of assets and liabilities measured on recurring basis
Short-term investments	$ 36.8	$ 138.6
Forward contracts	10.4	8.4
Total	47.2	147.0
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair value of assets and liabilities measured on recurring basis
Short-term investments	36.8	138.6
Total	36.8	138.6
Significant Observable Inputs (Level 2)
Fair value of assets and liabilities measured on recurring basis
Forward contracts	10.4	8.4
Total	$ 10.4	$ 8.4

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Equivalents
-URI http://asc.fasb.org/extlink&oid=6507016

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant