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Financial Instruments - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Derivative [Line Items] |  |  |
Interest rate cap, fair value | $ 1.0 | $ 1.0 |
Unrealized gain (loss) on effective portion of interest rate cap agreement | 0.6 | 11.3 | $ 5.9
Interest Rate Cap |  |  |
Derivative [Line Items] |  |  |
Notional amount | 1,400.0 | 2,800.0 |
Interest Rate Cap Agreement Effective December 31, 2020 |  |  |
Derivative [Line Items] |  |  |
Notional amount | 1,400.0 |  |
Interest Rate Contract |  |  |
Derivative [Line Items] |  |  |
Unrealized gain (loss) on effective portion of interest rate cap agreement | (0.6) | (11.3) | (5.9)
Amount expected to be reclassified from AOCL to interest expense | (3.0) |  |
Derivative |  |  |
Derivative [Line Items] |  |  |
Interest income (expense) reclassified into earnings (less than) | (6.0) | $ (1.7) | $ (3.9)
Interest Rate Cap Agreement Effective December 31, 2022 |  |  |
Derivative [Line Items] |  |  |
Notional amount | $ 1,400.0 |  |

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- Definition The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=121549185&loc=d3e80748-113994 + Details
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- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
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