CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2019
Statement of Stockholders' Equity [Abstract]
Convertible notes conversion discount, taxes	$ 4.1	$ 4.1	$ 4.1
Issuance cost, equity component		$ 1.1

The tax effect of an increase or decrease in contributed capital (for example, deductible expenditures reported as a reduction of the proceeds from issuing capital stock) during the period charged or credited directly to shareholders' equity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 20
-Section 45
-Paragraph 11
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109238882&loc=d3e39076-109324

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 20
-Section 45
-Paragraph 2
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=109238882&loc=d3e38679-109324

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