Business Combinations - Summary of Net Assets Acquired from Acquisition (Details) - USD ($) $ in Millions								9 Months Ended		12 Months Ended
	Sep. 01, 2021	Mar. 01, 2021	Oct. 30, 2020	Sep. 01, 2020	Jul. 01, 2020	Jun. 12, 2020	Feb. 14, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Business Acquisition [Line Items]
Goodwill								$ 25.2		$ 24.3
Assets acquired net of cash					$ 2.1	$ 3.0		3.9	$ 128.8
ScottTech, LLC
Business Acquisition [Line Items]
Cash		$ 0.5
Accounts receivable		0.9
Inventory		0.3
Prepaid and other assets		0.1
Property and equipment, net		0.4
Goodwill		1.5
Total Assets		3.7
Accounts payable		(0.3)
Accrued expenses		(0.1)
Other current liabilities		(0.9)
Total liabilities		(1.3)
Net Assets Acquired		2.4
Assets acquired net of cash		$ 1.9
Baron Industries
Business Acquisition [Line Items]
Inventory	$ 0.3
Prepaid and other assets	0.3
Property and equipment, net	0.2
Goodwill	0.8
Total Assets	1.6
Other current liabilities	(0.3)
Total liabilities	(0.3)
Net Assets Acquired	1.3
Assets acquired net of cash	$ 1.3
FlaglerCE Holdings LLC
Business Acquisition [Line Items]
Cash							$ 0.4
Accounts receivable							15.1
Inventory							37.5
Prepaid and other assets							0.5
Rental fleet, net							47.8
Property and equipment, net							2.9
Intangible assets							14.6
Goodwill							5.8
Total Assets							124.6
Floor plan payable							29.0
Accounts payable							(14.0)
Accrued expenses							(4.1)
Other liabilities							1.3
Total liabilities							(48.4)
Net Assets Acquired							76.2
Assets acquired net of cash							75.8
Floor plan payable							(29.0)
Other liabilities							(1.3)
Liftech Equipment Companies, Inc.
Business Acquisition [Line Items]
Accounts receivable							4.4
Inventory							9.6
Prepaid and other assets							1.0
Rental fleet, net							4.7
Property and equipment, net							1.2
Intangible assets							1.2
Goodwill							1.5
Total Assets							23.6
Floor plan payable							3.5
Accounts payable							(1.6)
Other current liabilities							(0.1)
Total liabilities							(5.2)
Net Assets Acquired							18.4
Assets acquired net of cash							18.4
Floor plan payable							$ (3.5)
Peak Logix LLC
Business Acquisition [Line Items]
Cash						3.0
Accounts receivable						4.6
Inventory						0.4
Prepaid and other assets						0.2
Property and equipment, net						0.2
Intangible assets						5.8
Goodwill						0.7
Total Assets						14.9
Accounts payable						(1.5)
Accrued expenses						(0.1)
Other current liabilities						(3.9)
Total liabilities						(5.5)
Net Assets Acquired						9.4
Assets acquired net of cash						$ 6.4
Hilo Equipment & Services
Business Acquisition [Line Items]
Cash					2.1
Accounts receivable					5.4
Inventory					4.7
Prepaid and other assets					0.2
Rental fleet, net					7.5
Property and equipment, net					1.7
Intangible assets					2.4
Goodwill					3.2
Total Assets					27.2
Floor plan payable					4.4
Accounts payable					(2.8)
Accrued expenses					(0.3)
Other current liabilities					(0.4)
Total liabilities					(7.9)
Net Assets Acquired					19.3
Assets acquired net of cash					17.2
Floor plan payable					$ (4.4)
Martin Implement Sales, Inc.
Business Acquisition [Line Items]
Accounts receivable				$ 1.0
Inventory				6.8
Rental fleet, net				6.3
Intangible assets				1.5
Goodwill				0.8
Total Assets				16.4
Accounts payable				(0.2)
Accrued expenses				(0.1)
Total liabilities				(0.3)
Net Assets Acquired				16.1
Assets acquired net of cash				$ 16.1
Howell Tractor and Equipment, LLC
Business Acquisition [Line Items]
Accounts receivable			$ 5.2
Inventory			6.3
Rental fleet, net			12.4
Property and equipment, net			1.1
Intangible assets			2.4
Goodwill			1.7
Total Assets			29.1
Floor plan payable			0.8
Accounts payable			(1.0)
Accrued expenses			(0.3)
Total liabilities			(2.1)
Net Assets Acquired			27.0
Assets acquired net of cash			27.0
Floor plan payable			$ (0.8)
Vantage Equipment, LLC
Business Acquisition [Line Items]
Accounts receivable										3.6
Inventory										7.5
Rental fleet, net										15.9
Property and equipment, net										1.0
Goodwill										0.5
Total Assets										28.5
Floor plan payable										2.1
Accounts payable										(1.4)
Accrued expenses										(0.6)
Other current liabilities										(0.1)
Total liabilities										(4.2)
Net Assets Acquired								$ 0.1		24.3
Assets acquired net of cash										24.3
Floor plan payable										(2.1)
Flagler, Liftech, Peak, Hilo, Martin, Howell and Vantage
Business Acquisition [Line Items]
Cash										5.5
Accounts receivable										39.3
Inventory										72.8
Prepaid and other assets										1.9
Rental fleet, net										94.6
Property and equipment, net										8.1
Intangible assets										27.9
Goodwill										14.2
Total Assets										264.3
Floor plan payable										39.8
Accounts payable										(22.5)
Accrued expenses										(5.5)
Other current liabilities										(4.5)
Other liabilities										1.3
Total liabilities										(73.6)
Net Assets Acquired										190.7
Assets acquired net of cash										185.2
Floor plan payable										(39.8)
Other liabilities										$ (1.3)