CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Mar. 31, 2021
Convertible Senior Notes Due 2026
Convertible notes conversion discount, taxes	$ (5.4)
Convertible Notes \| Convertible Senior Notes due 2024
Convertible notes conversion discount, taxes	1.8
Issuance cost, equity component		$ 1.1
Convertible Notes \| Convertible Senior Notes Due 2026
Convertible notes conversion discount, taxes	6.2
Issuance cost, equity component	$ 0.9	$ 0.9

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://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 20
-Section 45
-Paragraph 11
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=120385591&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=120385591&loc=d3e38679-109324

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