Segment Reporting - Summarized Financial Information for Company's Reportable Segments (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024		Dec. 31, 2024
Segment Reporting Information [Line Items]
Rental revenues		$ 120,113	$ 120,332
Rental related services revenues		33,916	29,580
Total revenues		195,416	187,827
Depreciation of rental equipment		21,505	22,366
Rental related services		24,313	20,786
Other		27,652	29,010
Costs of sales		25,510	22,397
Total costs of revenues		98,980	94,559
Gross profit		96,436	93,268
Wages and benefits	[1]	21,729	21,638
Depreciation and amortization	[1]	4,016	3,945
Marketing and administrative expenses	[1]	8,199	8,256
Allocated corporate services	[1],[2]	16,564	16,367
Other segment items	[1],[3]	361	258
Total expenses	[1]	50,869	50,464
Income from operations	[1]	45,567	52,085
Other income, net		0	(9,281)	[1]
Segment profit	[1]	45,567	52,085
Total segment gross profit			93,268
Interest expense (income) allocation	[1]	8,158	12,704
Foreign currency exchange (gain) loss	[1]	(5)	132
WillScot Mobile Mini transaction costs (Note 1)		0	9,354
Income before provision for income taxes	[1]	37,414	39,249
Income before provision for income taxes		37,414	29,895
Rental equipment acquisitions		9,579	67,784
Accounts receivable, net (period end)		208,882	211,950		$ 219,342
Rental equipment, at cost (period end)		1,988,993	1,957,077		1,999,195
Rental equipment, net book value (period end)		1,369,303	1,368,542		$ 1,387,659
Sales [Member]
Segment Reporting Information [Line Items]
Revenues		38,926	35,069
Other [Member]
Segment Reporting Information [Line Items]
Revenues		2,461	2,846
Mobile Modular [Member]
Segment Reporting Information [Line Items]
Rental revenues		78,496	76,496
Rental related services revenues		29,475	24,133
Total revenues		131,919	127,585
Depreciation of rental equipment		10,554	9,874
Rental related services		19,740	15,780
Other		20,812	22,673
Costs of sales		15,345	17,413
Total costs of revenues		66,451	65,740
Gross profit		65,468	61,845
Wages and benefits	[1]	14,110	14,262
Depreciation and amortization	[1]	3,531	3,380
Marketing and administrative expenses	[1]	4,666	4,718
Allocated corporate services	[1],[2]	11,554	11,191
Other segment items	[1],[3]	127	63
Total expenses	[1]	33,988	33,614
Income from operations	[1]	31,480	34,451
Other income, net	[1]		(6,220)
Segment profit	[1]	31,480	34,451
Interest expense (income) allocation	[1]	6,505	9,799
Income before provision for income taxes	[1]	24,975	24,652
Rental equipment acquisitions		4,400	59,263
Accounts receivable, net (period end)		159,672	166,382
Rental equipment, at cost (period end)		1,414,535	1,345,919
Rental equipment, net book value (period end)		$ 1,051,635	$ 1,013,965
Utilization (period end)	[4]	74.30%	78.50%
Average utilization	[4]	74.60%	78.70%
Mobile Modular [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Revenues		$ 22,490	$ 25,326
Mobile Modular [Member] | Other [Member]
Segment Reporting Information [Line Items]
Revenues		1,458	1,630
Portable Storage [Member]
Segment Reporting Information [Line Items]
Rental revenues		16,074	18,407
Rental related services revenues		3,631	4,723
Total revenues		21,265	24,760
Depreciation of rental equipment		1,031	965
Rental related services		3,933	4,456
Other		1,527	1,468
Costs of sales		831	768
Total costs of revenues		7,322	7,657
Gross profit		13,943	17,103
Wages and benefits	[1]	3,524	3,516
Depreciation and amortization	[1]	357	442
Marketing and administrative expenses	[1]	1,640	1,595
Allocated corporate services	[1],[2]	1,864	2,122
Other segment items	[1],[3]	170	134
Total expenses	[1]	7,555	7,809
Income from operations	[1]	6,388	10,613
Other income, net	[1]		(1,319)
Segment profit	[1]	6,388	10,613
Interest expense (income) allocation	[1]	971	1,420
Income before provision for income taxes	[1]	5,417	9,193
Rental equipment acquisitions		357	5,128
Accounts receivable, net (period end)		10,397	14,117
Rental equipment, at cost (period end)		240,348	240,517
Rental equipment, net book value (period end)		$ 217,060	$ 220,811
Utilization (period end)	[4]	61.00%	68.80%
Average utilization	[4]	60.20%	69.80%
Portable Storage [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Revenues		$ 1,244	$ 1,212
Portable Storage [Member] | Other [Member]
Segment Reporting Information [Line Items]
Revenues		316	418
TRS-RenTelco [Member]
Segment Reporting Information [Line Items]
Rental revenues		25,543	25,429
Rental related services revenues		810	724
Total revenues		35,019	33,763
Depreciation of rental equipment		9,920	11,527
Rental related services		640	550
Other		5,313	4,869
Costs of sales		4,271	2,942
Total costs of revenues		20,144	19,888
Gross profit		14,875	13,875
Wages and benefits	[1]	2,899	2,695
Depreciation and amortization	[1]	26	26
Marketing and administrative expenses	[1]	1,303	1,401
Allocated corporate services	[1],[2]	3,146	3,054
Other segment items	[1],[3]	64	61
Total expenses	[1]	7,438	7,237
Income from operations	[1]	7,437	8,380
Other income, net	[1]		(1,742)
Segment profit	[1]	7,437	8,380
Interest expense (income) allocation	[1]	1,277	2,062
Foreign currency exchange (gain) loss	[1]	(5)	132
Income before provision for income taxes	[1]	6,165	6,186
Rental equipment acquisitions		4,822	3,393
Accounts receivable, net (period end)		22,388	22,637
Rental equipment, at cost (period end)		334,110	370,641
Rental equipment, net book value (period end)		$ 100,608	$ 133,766
Utilization (period end)	[4]	64.90%	56.80%
Average utilization	[4]	61.60%	56.50%
TRS-RenTelco [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Revenues		$ 7,979	$ 6,812
TRS-RenTelco [Member] | Other [Member]
Segment Reporting Information [Line Items]
Revenues		687	798
Enviroplex [Member]
Segment Reporting Information [Line Items]
Total revenues	[5]	7,213	1,719
Costs of sales	[5]	5,063	1,274
Total costs of revenues	[5]	5,063	1,274
Gross profit	[5]	2,150	445
Wages and benefits	[1],[5]	1,196	1,165
Depreciation and amortization	[1],[5]	102	97
Marketing and administrative expenses	[1],[5]	590	542
Total expenses	[1],[5]	1,888	1,804
Income from operations	[1],[5]	262	(1,359)
Segment profit	[1],[5]	262	(1,359)
Interest expense (income) allocation	[1],[5]	(595)	(577)
Income before provision for income taxes	[1],[5]	857	(782)
Accounts receivable, net (period end)	[5]	16,425	8,814
Enviroplex [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Revenues	[5]	$ 7,213	$ 1,719

[1] The Significant Segment Expense categories and amounts align with the segment-level information that is regularly provided to the CODM.

[2] Allocated corporate services costs are comprised of expenses incurred by the Company which are not directly incurred by each business segment as a part of their normal operations. These allocated indirect corporate costs primarily include wages and benefits, depreciation of corporate capital assets, information technology, legal, accounting and other administrative expenses.

[3] Other segment items for each reportable segment is primarily comprised of credit losses.

[4] Utilization is calculated each month by dividing the cost of rental equipment on rent by the total cost of rental equipment excluding new equipment inventory and accessory equipment. The average utilization for the period is calculated using the average costs of rental equipment.

[5] Gross Enviroplex sales revenues were $7,213 and $1,719 for the three months ended March 31, 2025 and 2024, respectively. There were no inter-segment sales to Mobile Modular in the three months ended March 31, 2025 and $1,845 inter-segment sales to Mobile Modular for the same period in 2024, which required elimination in consolidation.