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Summary of Significant Accounting Policies (Details) $ in Millions | 9 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2019 USD ($) segment | Jan. 01, 2019 USD ($) | Dec. 31, 2018 USD ($)
Operating lease assets | $ 422.0 |  | $ 0.0
Operating lease liabilities | $ 481.1 |  |
Number of reportable segments | segment | 1 |  |
Interest in subsidiary (less than given percentage) | 100.00% |  |
Accounting Standards Update 2016-02 |  |  |
Operating lease assets |  | $ 463.0 |
Operating lease liabilities |  | $ 526.0 |

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- Definition Present value of lessee's discounted obligation for lease payments from operating lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977 + Details
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