Segment Reporting - Summarized Financial Information for Company's Reportable Segments (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022		Jun. 30, 2021		Dec. 31, 2021
Segment Reporting Information [Line Items]
Rental revenues		$ 110,624	$ 94,581	$ 214,865		$ 180,668
Rental related services revenues		28,819	22,688	53,136		42,357
Sales and other revenues				54,403		44,605
Total revenues		177,031	146,435	322,404		267,630
Depreciation of rental equipment		24,064	23,159	47,938		44,414
Gross profit		77,837	65,867	144,326		122,948
Selling and administrative expenses		40,788	36,261	79,915		69,398
Income from operations		37,049	29,606	64,411		53,550
Interest (expense) income allocation				(5,821)		(4,040)
Income (loss) before provision for income taxes		33,867	27,347	58,422		49,453
Adjusted EBITDA				123,010		107,649
Rental equipment acquisitions				95,976		190,747
Accounts receivable, net (period end)		167,329	140,909	167,329		140,909		$ 159,499
Rental equipment, at cost (period end)		1,774,291	1,694,094	1,774,291		1,694,094		1,711,393
Rental equipment, net book value (period end)		1,097,525	1,073,055	1,097,525		1,073,055		$ 1,065,224
Mobile Modular [Member]
Segment Reporting Information [Line Items]
Rental revenues				126,487		99,895
Rental related services revenues				39,594		30,258
Sales and other revenues				35,941		23,067
Total revenues		111,377	84,572	202,022		153,220
Depreciation of rental equipment				15,582		12,893
Gross profit				92,820		75,693
Selling and administrative expenses				50,447		41,839
Income from operations				42,373		33,854
Interest (expense) income allocation				(3,821)		(2,426)
Income (loss) before provision for income taxes				38,552		31,428
Adjusted EBITDA				66,178		53,473
Rental equipment acquisitions				51,575		148,252
Accounts receivable, net (period end)		118,865	96,976	118,865		96,976
Rental equipment, at cost (period end)		1,075,898	1,019,697	1,075,898		1,019,697
Rental equipment, net book value (period end)		776,003	739,916	$ 776,003		$ 739,916
Utilization (period end)	[1]			78.60%		76.30%
Average utilization	[1]			77.60%		75.70%
TRS-RenTelco [Member]
Segment Reporting Information [Line Items]
Rental revenues				$ 58,230		$ 55,136
Rental related services revenues				1,484		1,450
Sales and other revenues				11,118		10,800
Total revenues		37,341	33,783	70,832		67,386
Depreciation of rental equipment				24,362		23,278
Gross profit				30,826		29,365
Selling and administrative expenses				13,204		12,371
Income from operations				17,622		16,994
Interest (expense) income allocation				(1,232)		(920)
Income (loss) before provision for income taxes				16,222		16,017
Adjusted EBITDA				42,781		41,411
Rental equipment acquisitions				42,791		42,421
Accounts receivable, net (period end)		24,796	22,678	24,796		22,678
Rental equipment, at cost (period end)		389,383	360,720	389,383		360,720
Rental equipment, net book value (period end)		177,038	172,035	$ 177,038		$ 172,035
Utilization (period end)	[1]			65.30%		66.90%
Average utilization	[1]			64.60%		67.70%
Adler Tanks [Member]
Segment Reporting Information [Line Items]
Rental revenues				$ 30,148		$ 25,637
Rental related services revenues				12,058		10,649
Sales and other revenues				1,777		1,382
Total revenues		23,663	19,958	43,983		37,668
Depreciation of rental equipment				7,994		8,243
Gross profit				19,335		15,019
Selling and administrative expenses				13,501		12,520
Income from operations				5,834		2,499
Interest (expense) income allocation				(1,119)		(922)
Income (loss) before provision for income taxes				4,715		1,577
Adjusted EBITDA				15,327		12,436
Rental equipment acquisitions				1,610		74
Accounts receivable, net (period end)		17,248	13,545	17,248		13,545
Rental equipment, at cost (period end)		309,010	313,677	309,010		313,677
Rental equipment, net book value (period end)		144,484	161,104	$ 144,484		$ 161,104
Utilization (period end)	[1]			51.80%		45.80%
Average utilization	[1]			49.90%		42.10%
Enviroplex [Member]
Segment Reporting Information [Line Items]
Sales and other revenues	[2]			$ 5,567		$ 9,356
Total revenues		4,650	8,122	5,567	[2]	9,356	[2]
Gross profit	[2]			1,345		2,871
Selling and administrative expenses	[2]			2,763		2,668
Income from operations	[2]			(1,418)		203
Interest (expense) income allocation	[2]			351		228
Income (loss) before provision for income taxes	[2]			(1,067)		431
Adjusted EBITDA	[2]			(1,276)		329
Accounts receivable, net (period end)	[2]	$ 6,420	$ 7,710	$ 6,420		$ 7,710

[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 $6,423 and $10,211 for the six months ended June 30, 2022 and 2021, respectively. There were $856 and $855 inter-segment sales to Mobile Modular in the six months ended June 30, 2022 and 2021, respectively, which required elimination in consolidation.