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Financial Instruments - Narrative (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Cap agreement effective 1/1/17-12/31/18 |  |
Derivative [Line Items] |  |
Interest rate cap, cap rate | 1.50% |
Notional amount | $ 1,400 |
Interest rate cap, fair value | 5 | $ 5
Interest Rate Contract |  |
Derivative [Line Items] |  |
Amount to be reclassified from AOCL to interest expense | 5 |
Derivative |  |
Derivative [Line Items] |  |
Interest gain (loss) reclassified to earnings | $ 1 | $ 3

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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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994 + Details
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