SIGNIFICANT ACCOUNTING POLICIES - INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
SIGNIFICANT ACCOUNTING POLICIES
Tax Act, income tax expense (benefit)	$ 0.0	$ 0.0		$ (3.1)
Remeasurement and discrete adjustments related to the Tax Act			$ (2.9)
Sequestration rate (as a percent)				6.20%

Internal Revenue Service sequestration rate on alternative minimum tax refunds.

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- References

No definition available.

+ Details

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- Definition

Amount of income tax expense (benefit) from effect of Tax Cuts and Jobs Act.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319

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- Definition

Amount of reasonable estimate for income tax expense (benefit) for which accounting for tax effect for remeasurement of deferred tax from change in tax rate is incomplete pursuant to Tax Cuts and Jobs Act.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2A
-Subparagraph (SAB Topic 5.EE.Q2(b))
-URI http://asc.fasb.org/extlink&oid=116825942&loc=SL116722634-122817

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