Employee Benefit Plan (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Benefit Plan
Employer matching contribution on 3% participating employees' contributions	100.00%
Percentage of employees' gross pay for which the employer contributes a 100% matching contribution to a defined contribution plan.	3.00%
Employer matching contribution on 2% participating employees' contributions	50.00%
Percentage of participating employees' contributions for 50% employer matching contribution	2.00%
Employer matching contribution	$ 1.8	$ 2.0	$ 2.1
Maximum percentage	4.00%
Minimum percentage	5.00%

Defined contribution plan employee minimum matching contribution.

No definition available.

Name:	rdbx_DefinedContributionPlanEmployeeMinimumMatchingContribution
Namespace Prefix:	rdbx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Defined contribution plan maximum employer matching contribution.

No definition available.

Name:	rdbx_DefinedContributionPlanEmployerMatchingContributionMaximumPercentOfMatch
Namespace Prefix:	rdbx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of employees' gross pay for which the employer contributes a 100% matching contribution to a defined contribution plan.

No definition available.

Name:	rdbx_DefinedContributionPlanEmployerMatchingContributionPercentOfEmployeesGrossPayOne
Namespace Prefix:	rdbx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of employees' gross pay for which the employer contributes a 50% matching contribution to a defined contribution plan.

No definition available.

Name:	rdbx_DefinedContributionPlanEmployerMatchingContributionPercentOfEmployeesGrossPayTwo
Namespace Prefix:	rdbx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage employer matches of the employee's percentage contribution matched on the first 3% of participating employees' contributions.

No definition available.

Name:	rdbx_DefinedContributionPlanEmployerMatchingContributionPercentOfMatchOne
Namespace Prefix:	rdbx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage employer matches of the employee's percentage contribution matched on the first 2% of participating employees' contributions.

No definition available.

Name:	rdbx_DefinedContributionPlanEmployerMatchingContributionPercentOfMatchTwo
Namespace Prefix:	rdbx_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

No definition available.

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

Amount of discretionary contributions made by an employer to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration