Segment Reporting - Summarized Financial Information for Company's Reportable Segments (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022		Sep. 30, 2021		Dec. 31, 2021
Segment Reporting Information [Line Items]
Rental revenues		$ 118,361	$ 103,269	$ 333,226		$ 283,937
Rental related services revenues		35,361	31,513	88,497		73,870
Sales and other revenues				101,217		83,115
Total revenues		200,536	173,292	522,940		440,922
Depreciation of rental equipment		24,176	23,802	72,114		68,216
Gross profit		89,440	75,805	233,766		198,753
Selling and administrative expenses		44,095	39,907	124,010		109,305
Income from operations		45,345	35,898	109,756		89,448
Interest (expense) income allocation				(9,998)		(7,208)
Income (loss) before provision for income taxes		40,932	32,602	99,354		82,055
Adjusted EBITDA				197,730		173,612
Rental equipment acquisitions				134,131		215,904
Accounts receivable, net (period end)		189,959	168,831	189,959		168,831		$ 159,499
Rental equipment, at cost (period end)		1,790,735	1,698,820	1,790,735		1,698,820		1,711,393
Rental equipment, net book value (period end)		1,099,822	1,063,462	1,099,822		1,063,462		$ 1,065,224
Mobile Modular [Member]
Segment Reporting Information [Line Items]
Rental revenues				195,598		159,118
Rental related services revenues				66,947		54,726
Sales and other revenues				65,315		49,770
Total revenues		125,838	110,394	327,860		263,614
Depreciation of rental equipment				23,329		20,437
Gross profit				149,405		125,357
Selling and administrative expenses				79,245		67,977
Income from operations				70,160		57,380
Interest (expense) income allocation				(6,616)		(4,401)
Income (loss) before provision for income taxes				63,544		52,979
Adjusted EBITDA				105,912		89,634
Rental equipment acquisitions				73,895		162,579
Accounts receivable, net (period end)		139,730	118,467	139,730		118,467
Rental equipment, at cost (period end)		1,085,060	1,023,344	1,085,060		1,023,344
Rental equipment, net book value (period end)		780,939	737,807	$ 780,939		$ 737,807
Utilization (period end)	[1]			81.20%		76.70%
Average utilization	[1]			78.50%		76.00%
TRS-RenTelco [Member]
Segment Reporting Information [Line Items]
Rental revenues				$ 89,990		$ 84,340
Rental related services revenues				2,329		2,149
Sales and other revenues				17,040		15,971
Total revenues		38,527	35,074	109,359		102,460
Depreciation of rental equipment				36,789		35,429
Gross profit				48,824		44,867
Selling and administrative expenses				19,930		18,381
Income from operations				28,894		26,486
Interest (expense) income allocation				(2,160)		(1,588)
Income (loss) before provision for income taxes				26,330		24,713
Adjusted EBITDA				66,675		63,378
Rental equipment acquisitions				57,169		53,161
Accounts receivable, net (period end)		24,353	24,854	24,353		24,854
Rental equipment, at cost (period end)		396,068	363,799	396,068		363,799
Rental equipment, net book value (period end)		177,221	169,250	$ 177,221		$ 169,250
Utilization (period end)	[1]			65.20%		66.90%
Average utilization	[1]			64.80%		67.40%
Adler Tanks [Member]
Segment Reporting Information [Line Items]
Rental revenues				$ 47,638		$ 40,479
Rental related services revenues				19,221		16,995
Sales and other revenues				3,317		2,477
Total revenues		26,193	22,283	70,176		59,951
Depreciation of rental equipment				11,996		12,350
Gross profit				31,933		24,167
Selling and administrative expenses				20,642		18,853
Income from operations				11,291		5,314
Interest (expense) income allocation				(1,941)		(1,560)
Income (loss) before provision for income taxes				9,350		3,754
Adjusted EBITDA				25,520		20,144
Rental equipment acquisitions				3,067		164
Accounts receivable, net (period end)		18,185	16,062	18,185		16,062
Rental equipment, at cost (period end)		309,607	311,677	309,607		311,677
Rental equipment, net book value (period end)		141,662	156,405	$ 141,662		$ 156,405
Utilization (period end)	[1]			58.30%		50.40%
Average utilization	[1]			51.70%		44.00%
Enviroplex [Member]
Segment Reporting Information [Line Items]
Sales and other revenues	[2]			$ 15,545		$ 14,897
Total revenues		9,978	5,541	15,545	[2]	14,897	[2]
Gross profit	[2]			3,604		4,362
Selling and administrative expenses	[2]			4,193		4,094
Income from operations	[2]			(589)		268
Interest (expense) income allocation	[2]			719		341
Income (loss) before provision for income taxes	[2]			130		(609)
Adjusted EBITDA	[2]			(377)		456
Accounts receivable, net (period end)	[2]	$ 7,691	$ 9,448	$ 7,691		$ 9,448

[1] Utilization is calculated each month by dividing the cost of rental equipment on rent by the total cost of rental equipment, excluding accessory equipment, and for Mobile Modular and Adler Tanks, excluding new equipment inventory. The Average utilization for the period is calculated using the average costs of rental equipment.

[2] Gross Enviroplex sales revenues were $16,401 and $15,909 for the nine months ended September 30, 2022 and 2021, respectively. There were $856 and $1,012 inter-segment sales to Mobile Modular in the nine months ended September 30, 2022 and 2021, respectively, which required elimination in consolidation.