Income Taxes - Difference Between Customary Rate and Effective Tax Rate on Income Before Income Taxes Due (Detail)	5 Months Ended	7 Months Ended	12 Months Ended
Dec. 31, 2018	Aug. 13, 2018	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Tax at statutory rate	21.00%	21.00%	21.00%	21.00%
Tax effect of:
Alternative minimum tax	(1.60%)	0.00%	0.00%	0.00%
Valuation allowance on deferred tax assets	(1.10%)	(24.10%)	1.50%	(0.40%)
State income taxes, net of federal benefit	4.70%	3.90%	(6.10%)	(0.40%)
Nondeductible transaction costs	0.00%	0.00%	0.00%	1.10%
Nondeductible stock-based compensation	(0.10%)	(0.70%)	(1.80%)	0.70%
Other	0.00%	(1.30%)	0.30%	0.30%
Effective tax rate	22.90%	(1.20%)	14.90%	22.30%

Effective income tax rate reconciliation alternative minimum tax credit refundable.

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Effective income tax rate reconciliation nondeductible expense transaction costs.

+ References

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.Fact.4)
-URI http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817

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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 6.I.Fact.4)
-URI http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817

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-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

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Percentage of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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