STOCKHOLDERS' EQUITY - Components of Accumulated Other Comprehensive Income, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (108.5)	$ (110.7)	$ (162.5)	$ (24.2)
Other comprehensive income (loss) before reclassifications	29.6	(46.8)	85.0	(130.8)
Amounts reclassified from accumulated other comprehensive income (loss)	(0.9)	13.3	(2.3)	10.8
Net current-period other comprehensive income (loss)	28.7	(33.5)	82.7	(120.0)
Ending balance	(79.8)	(144.2)	(79.8)	(144.2)
Gains (Losses) on Hedge Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(0.4)	5.5	(2.9)	4.5
Other comprehensive income (loss) before reclassifications	6.9	(9.0)	10.6	(5.3)
Amounts reclassified from accumulated other comprehensive income (loss)	(0.9)	13.4	(2.1)	10.7
Net current-period other comprehensive income (loss)	6.0	4.4	8.5	5.4
Ending balance	5.6	9.9	5.6	9.9
Unrealized Gains (Losses) on Available-for-Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(116.6)	(106.7)	(154.2)	(16.0)
Other comprehensive income (loss) before reclassifications	13.1	(33.3)	50.9	(124.1)
Amounts reclassified from accumulated other comprehensive income (loss)	0.0	(0.1)	(0.2)	0.0
Net current-period other comprehensive income (loss)	13.1	(33.4)	50.7	(124.1)
Ending balance	(103.5)	(140.1)	(103.5)	(140.1)
Foreign Currency Translation Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	7.3	(4.8)	(6.6)	(7.9)
Other comprehensive income (loss) before reclassifications	9.6	(4.5)	23.5	(1.4)
Amounts reclassified from accumulated other comprehensive income (loss)	0.0	0.0	0.0	0.0
Net current-period other comprehensive income (loss)	9.6	(4.5)	23.5	(1.4)
Ending balance	16.9	(9.3)	16.9	(9.3)
Employee Benefit Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	1.2	(4.7)	1.2	(4.8)
Other comprehensive income (loss) before reclassifications	0.0	0.0	0.0	0.0
Amounts reclassified from accumulated other comprehensive income (loss)	0.0	0.0	0.0	0.1
Net current-period other comprehensive income (loss)	0.0	0.0	0.0	0.1
Ending balance	$ 1.2	$ (4.7)	$ 1.2	$ (4.7)

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

Name:	us-gaap_AOCIAttributableToParentNetOfTaxRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after tax, of accumulated increase (decrease) in equity from transaction and other event and circumstance from nonowner source.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-14A

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-11

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (g)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 65
-Paragraph 2
-Subparagraph (h)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480016/944-40-65-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(30)(a)(4))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(23)(a)(3))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-14

+ Details

Name:	us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount before tax and reclassification adjustments of other comprehensive income (loss) attributable to parent.

+ References

+ Details

Name:	us-gaap_OciBeforeReclassificationsBeforeTaxAttributableToParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount after tax of other comprehensive income (loss) attributable to parent entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 810
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 19
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481231/810-10-45-19

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 20
-SubTopic 10
-Topic 810
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481231/810-10-45-20

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (c)(3)
-SubTopic 10
-Topic 810
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481203/810-10-50-1A

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1B
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1B

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-1A

+ Details

Name:	us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount before tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.

+ References

+ Details

Name:	us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedTranslationAdjustmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: