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Derivative Financial Instruments - Effect on Statement of Comprehensive Income and Statement of Income (Details) - Designated as Hedging Instrument - Derivatives in Net Investment Hedging Relationship - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018
Derivative [Line Items] |  |  |
Gain (Loss) Recorded in Other Comprehensive Income |  | $ (11.4) | $ 1.0
Gain Reclassified from Accumulated Other Comprehensive Income into Earnings |  | 0.5 | (0.1)
Gain Recorded in Earnings from Excluded Components | [1] | 13.9 | 3.8
Forward contracts |  |  |
Derivative [Line Items] |  |  |
Gain (Loss) Recorded in Other Comprehensive Income |  | (21.7) | 27.2
Gain Reclassified from Accumulated Other Comprehensive Income into Earnings |  | 0.5 | (0.1)
Gain Recorded in Earnings from Excluded Components | [1] | 13.9 | 3.8
Put options |  |  |
Derivative [Line Items] |  |  |
Gain (Loss) Recorded in Other Comprehensive Income |  | 29.3 | (17.8)
Gain Reclassified from Accumulated Other Comprehensive Income into Earnings |  | 0.0 | 0.0
Gain Recorded in Earnings from Excluded Components | [1] | 0.0 | 0.0
Call options |  |  |
Derivative [Line Items] |  |  |
Gain (Loss) Recorded in Other Comprehensive Income |  | (19.0) | (8.4)
Gain Reclassified from Accumulated Other Comprehensive Income into Earnings |  | 0.0 | 0.0
Gain Recorded in Earnings from Excluded Components | [1] | $ 0.0 | $ 0.0
[1] | The excluded components of the forward contracts are recorded in earnings on a straight-line basis over the respective period of the contracts as a reduction to Interest expense.

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- Definition Amount, before tax and adjustments, of gain (loss) from increase (decrease) in value of excluded component of derivative designated and qualifying as hedge. Adjustments include, but are not limited to, reclassifications for sale and settlement, and amounts recognized under systematic and rational method. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (dd) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=118930883&loc=d3e637-108580 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4CCC -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998896-113959 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 20 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109974929&loc=SL110061190-113977 + Details
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- Definition Amount, after tax, of reclassification from accumulated other comprehensive income (AOCI) of gain (loss) from increase (decrease) in fair value of net investment hedge. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4CCC -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998896-113959 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 10A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669646-108580 + Details
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