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

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-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=109197908&loc=d3e5070-113901

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- 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

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-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(3)
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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

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-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=109197908&loc=d3e5070-113901

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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

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-Publisher FASB
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-Topic 718
-SubTopic 10
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-Paragraph 2
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- 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)
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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 718
-SubTopic 10
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-Paragraph 2
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- 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
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- 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.

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-Publisher FASB
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-Topic 718
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-Paragraph 2
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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.

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No definition available.

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Summary of Restricted Stock Activity (Detail) - $ / shares	4 Months Ended	5 Months Ended	12 Months Ended
	Jul. 31, 2017	Dec. 31, 2017	Dec. 31, 2018	Mar. 31, 2017
Predecessor
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average Grant-Date Fair Value, Beginning Balance Outstanding	$ 24.19			$ 23.58
Weighted-average Grant-Date Fair Value, Ending Balance Outstanding				$ 24.19
Number of Shares Beginning Balance Outstanding	350,838			363,630
Number of Shares Ending Balance Outstanding				350,838
Restricted Stock Units (RSUs) \| Time Based Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average Grant-Date Fair Value, Beginning Balance Outstanding			$ 24.41
Weighted-average Grant-Date Fair Value, Granted		$ 24.40	24.58
Weighted-average Grant-Date Fair Value, Vested			24.84
Weighted-average Grant-Date Fair Value, Cancelled/forfeited		24.15	27.15
Weighted-average Grant-Date Fair Value, Ending Balance Outstanding		$ 24.41	$ 24.21
Number of Shares Beginning Balance Outstanding			1,157,646
Number of Shares, Granted		1,203,379	455,063
Number of Shares, Vested			(503,677)
Number of Shares, Cancelled/forfeited		(45,733)	(27,948)
Number of Shares Ending Balance Outstanding		1,157,646	1,081,084
Restricted Stock Units (RSUs) \| Time Based Shares \| Predecessor
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average Grant-Date Fair Value, Beginning Balance Outstanding	$ 54.48			$ 49.17
Weighted-average Grant-Date Fair Value, Vested	$ 54.48			49.39
Weighted-average Grant-Date Fair Value, Cancelled/forfeited				49.62
Weighted-average Grant-Date Fair Value, Ending Balance Outstanding				$ 54.48
Number of Shares Beginning Balance Outstanding	183			89,639
Number of Shares, Vested	(183)			(76,006)
Number of Shares, Cancelled/forfeited				(13,450)
Number of Shares Ending Balance Outstanding				183
Restricted Stock Units (RSUs) \| Performance Based Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average Grant-Date Fair Value, Granted			$ 26.04
Weighted-average Grant-Date Fair Value, Ending Balance Outstanding			$ 26.04
Number of Shares, Granted			63,365
Number of Shares Ending Balance Outstanding			63,365
Restricted Stock Units (RSUs) \| Performance Based Shares \| Predecessor
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average Grant-Date Fair Value, Beginning Balance Outstanding				$ 61.75
Weighted-average Grant-Date Fair Value, Cancelled/forfeited				$ 61.75
Weighted-average Grant-Date Fair Value, Ending Balance Outstanding
Number of Shares Beginning Balance Outstanding				156,851
Number of Shares, Cancelled/forfeited				(156,851)
Number of Shares Ending Balance Outstanding