Summary of Significant Accounting Policies - Additional Information (Details)			9 Months Ended		12 Months Ended
	Dec. 22, 2020 $ / shares	Nov. 03, 2020 USD ($) shares	Sep. 30, 2021 USD ($)	Sep. 30, 2020 USD ($)	Dec. 31, 2021 USD ($) vendor Segment $ / shares	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of vendors | vendor					2
Percentage of purchases of new equipment and parts inventory and rental fleet from vendors					35.00%	40.00%
Accounts receivable, net of allowances					$ 10,700,000	$ 7,100,000
Finance charges included in receivables					100,000	400,000
Inventory valuation reserves					$ 3,500,000	2,900,000
Property and equipment, depreciation methods					straight-line basis
Impairment of long-lived assets					$ 0	0
Goodwill impairment			$ 0	$ 0
Deferred financing costs and debt discounts					9,300,000	9,800,000
Accumulated amortization of deferred financing costs and debt discounts					1,900,000	1,800,000
Advertising and marketing costs					5,500,000	$ 3,500,000
Offering costs offset from proceeds of reverse capitalization					$ 2,600,000
Preferred stock, dividend rate, percentage	10.00%
Preferred stock, par value | $ / shares					$ 0.0001	$ 0.0001
Offering costs offset of proceeds from depositary shares					$ 1,800,000
Provision for federal income taxes					$ 2,800,000	$ (5,000,000.0)	$ 0
Partnership owned percentage in operating entity					100.00%
Number of reportable segments | Segment					2
ASC 280
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | Segment					2
Reportable segments description					The Company has determined in accordance with ASC 280, Segment Reporting (“ASC 280”), that it has two reportable segments: 1) Material Handling and 2) Construction Equipment.
10% Series A Cumulative Perpetual Preferred Stock
Summary Of Significant Accounting Policies [Line Items]
Depositary receipt ratio	0.001				0.001	0.001
Preferred stock, dividend rate, percentage	10.00%				10.00%	10.00%
Preferred stock, par value | $ / shares	$ 0.0001				$ 0.0001	$ 0.0001
Howell Tractor
Summary Of Significant Accounting Policies [Line Items]
Name of acquired entity						Howell Tractor
Business acquisition, shares issued | shares		507,143
Business acquisition, related costs		$ 200,000
Automated Equipment Installation and System Integration Services
Summary Of Significant Accounting Policies [Line Items]
Deferred revenue					$ 16,500,000	$ 9,600,000
Service Maintenance Contracts
Summary Of Significant Accounting Policies [Line Items]
Deferred revenue					16,500,000	9,600,000
Equipment Rental Agreements
Summary Of Significant Accounting Policies [Line Items]
Deferred revenue					16,500,000	9,600,000
Equipment
Summary Of Significant Accounting Policies [Line Items]
Deferred revenue					2,900,000	3,800,000
Recognized liability for guarantee to repurchase					7,200,000	9,000,000.0
Interest Expense
Summary Of Significant Accounting Policies [Line Items]
Amortization of deferred costs					$ 2,000,000.0	$ 1,800,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives					five years
Revenue from guaranteed maintenance contracts					3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Cash equivalents, original maturity					3 months
Property, plant and equipment, estimated useful lives					ten years
Revenue from guaranteed maintenance contracts					5 years
Contract term					1 year
Preliminary purchase price measurement period					1 year