Business Combination - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Apr. 01, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Total identifiable liabilities assumed		$ (489,442)
Goodwill	$ 684,796		$ 238,052
Trade names
Business Acquisition [Line Items]
Finite-lived intangible assets weighted average useful life	15 years
Customer relationships
Business Acquisition [Line Items]
Finite-lived intangible assets weighted average useful life	12 years
Custom Truck
Business Acquisition [Line Items]
Accounts and financing receivables		109,681
Inventory		434,328
Other current assets		14,080
Property and equipment		105,113
Rental equipment		567,366
Intangible assets		301,000
Operating lease assets		23,766
Other assets		18,223
Total identifiable assets acquired		1,573,557
Current liabilities		(410,276)
Long-term debt		(28,607)
Operating lease liabilities-noncurrent		(21,308)
Deferred tax and other liabilities		(29,251)
Total net assets		1,084,115
Goodwill		446,744
Net assets acquired (purchase price)		1,530,859
Gross contractual receivables		116,700
Estimated uncollectible receivables	$ 7,000
Custom Truck | Land, Buildings and Improvements
Business Acquisition [Line Items]
Property and equipment	67,900
Custom Truck | Machinery and Equipment and Vehicles
Business Acquisition [Line Items]
Property and equipment	31,100
Custom Truck | Other property
Business Acquisition [Line Items]
Property and equipment	$ 6,100
Custom Truck | Trade names
Business Acquisition [Line Items]
Intangible assets		151,000
Custom Truck | Customer relationships
Business Acquisition [Line Items]
Intangible assets		$ 150,000