Share-Based Compensation Arrangement By Share-Based Payment Award, Award Vesting Rights, Achievement Percentage

No definition available.

Name:	nls_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsAchievementPercentage
Namespace Prefix:	nls_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(3)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(2)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of vesting of award under share-based payment arrangement.

+ References

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_TitleOfIndividualAxis=nls_KeyExecutiveEmployeesMemberMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=nls_February2016PSUAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=nls_February2017PSUAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=nls_February2018PSUAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardDateAxis=nls_May2020PSUAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stock-Based Compensation - Performance Stock Units (Details) - Performance Shares - $ / shares	1 Months Ended				12 Months Ended
	May 31, 2020	Feb. 28, 2018	Feb. 28, 2017	Feb. 29, 2016	Dec. 31, 2020
Performance Stock Units Activity and Outstanding
Outstanding, beginning of period (in shares)					115,000
Granted (in shares)					263,000
Forfeited (in shares)					(55,000)
Vested (in shares)					0
Outstanding, end of period (in shares)					323,000
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Beginning of period, Weighted Average Grant Date Fair Value (in dollars per share)					$ 14.57
Granted, Weighted Average Grant Date Fair Value (in dollars per share)					6.64
Forfeited, Weighted Average Grante Date Fair Value (in dollars per share)					17.49
Vested, Weighted Average Grant Date Fair Value (in dollars per share)					0
End of period, Weighted Average Grant Date Fair Value (in dollars per share)					$ 7.62
Minimum \| Key Executive Employees Member
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting percentage					60.00%
Maximum \| Key Executive Employees Member
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting percentage					150.00%
February 2016 PSU Awards \| Key Executive Employees Member
Performance Stock Units Activity and Outstanding
Granted (in shares)				54,818
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting period					3 years
Achievement percentage				0.00%
February 2016 PSU Awards \| Minimum \| Key Executive Employees Member
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting percentage					60.00%
February 2016 PSU Awards \| Maximum \| Key Executive Employees Member
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting percentage					150.00%
February 2017 PSU Awards \| Key Executive Employees Member
Performance Stock Units Activity and Outstanding
Granted (in shares)			72,017
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting period					3 years
Achievement percentage			0.00%
February 2017 PSU Awards \| Minimum \| Key Executive Employees Member
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting percentage					60.00%
February 2017 PSU Awards \| Maximum \| Key Executive Employees Member
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting percentage					150.00%
February 2018 PSU Awards \| Key Executive Employees Member
Performance Stock Units Activity and Outstanding
Granted (in shares)		119,351
Outstanding, end of period (in shares)					60,000
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting period					3 years
February 2018 PSU Awards \| Minimum \| Key Executive Employees Member
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting percentage					60.00%
February 2018 PSU Awards \| Maximum \| Key Executive Employees Member
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting percentage					150.00%
May 2020 PSU Awards \| Key Executive Employees Member
Performance Stock Units Activity and Outstanding
Granted (in shares)	262,999
Outstanding, end of period (in shares)					263,000
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting period					3 years
Achievement percentage					100.00%
May 2020 PSU Awards \| Minimum \| Key Executive Employees Member
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting percentage					60.00%
May 2020 PSU Awards \| Maximum \| Key Executive Employees Member
Performance Stock Units Activity and Weighted Average Grant Date Fair Value per Share
Vesting percentage					150.00%