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Income Taxes - Summary of Components of Deferred and Other Tax Assets and Liabilities (Parenthetical) (Detail) - Medallion Chicago [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Income Tax Rate Reconciliation [Line Items]
Net operating loss carryforwards	$ 124,150
Net operating loss carryforwards expiration period	expires at various dates between December 31, 2026 and December 31, 2035
Net operating loss carryforwards assets	$ 30,031
December 31, 2026 To December 31, 2035 [Member]
Income Tax Rate Reconciliation [Line Items]
Net operating loss carryforwards	$ 1,712

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Income Tax Rate Reconciliation [Line Items]

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are subject to expiration dates.

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Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319

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