Tax Cuts And Jobs Act Of 2017, Incomplete Accounting, Change In Tax Rate, Deferred Tax Asset, Income Tax Expense

No definition available.

Name:	msl_TaxCutsAndJobsActOf2017IncompleteAccountingChangeInTaxRateDeferredTaxAssetIncomeTaxExpense
Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Tax Cuts And Jobs Act Of 2017, Reclassification From Aoci To Retained Earnings, Tax Effect

+ References

No definition available.

+ Details

Name:	msl_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarningsTaxEffect
Namespace Prefix:	msl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

+ Details

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

- 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

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

- Details

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

- Details

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

INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase to income tax expense	$ 3,600
Valuation allowance for deferred tax assets	$ 0	$ 0	$ 11,056
Accumulated Other Comprehensive Loss
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of stranded tax effects		(324)
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of stranded tax effects		$ 324