Exercise price per share or per unit of warrants or rights outstanding.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
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Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Face (par) amount of debt instrument at time of issuance.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
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Contractual interest rate for funds borrowed, under the debt agreement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Extension in period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of shares issued during the period as a result of expiration of warrants.

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Debt (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		4 Months Ended	9 Months Ended
	Sep. 30, 2017	Mar. 31, 2017	Mar. 31, 2017	Sep. 30, 2017	Jun. 01, 2017	Oct. 31, 2011
Credit Agreement 2016
Debt
Maximum borrowing capacity	$ 1,000.0			$ 1,000.0
Period of extension in maturity				1 year
Interest expense	$ 2.1			$ 3.7
Debt aggregate principal value					$ 250.0
Convertible Notes Due 2016
Debt
Debt aggregate principal value						$ 250.0
Stated percentage rate						1.00%
Sale of warrant
Share warrant, number of shares						5.2
Share warrant, strike price (in dollars per share)						$ 67.56
Shares issued upon expiration of warrants (shares)		1.7	2.8