Financial Instruments - Interest Rate Swap Hedges (Details) $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($) agreement	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Financial Instruments
Number of agreements held \| agreement	0
Interest rate swap hedges
Financial Instruments
Unrealized losses reclassified from accumulated other comprehensive loss to earnings	$ 3.6	$ 3.7	$ 3.7
Accelerated amortization of deferred realized losses	0.0	$ 1.4
Unrealized losses expected to be reclassified from accumulated other comprehensive loss to earnings within the next twelve months	$ 3.6		$ 0.0

The amount of expense charged to operations associated with accelerated amortization of deferred realized losses.

No definition available.

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- Definition

The amount of expense charged against earnings by an Entity to record deferred gains and losses on hedge instruments. Examples include gain on economic hedges, amortization of gain on designated fair value hedge and so forth.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

+ Details

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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=112277219&loc=d3e80748-113994

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

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- Details

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