Segment Reporting - Summarized Financial Information for Company's Reportable Segments (Parenthetical) (Detail) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019
Segment Reporting Information [Line Items]
Revenues		$ 156,448,000	$ 173,562,000	$ 423,574,000		$ 423,009,000
Sales revenues				(90,275,000)		(84,613,000)
Sales [Member]
Segment Reporting Information [Line Items]
Sales revenues		(42,331,000)	(50,855,000)	(87,366,000)		(81,387,000)
Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues		5,914,000	28,361,000	16,616,000	[1]	32,238,000	[1]
Sales revenues	[1]			(16,616,000)		(32,238,000)
Mobile Modular [Member]
Segment Reporting Information [Line Items]
Revenues		$ 95,413,000	$ 86,302,000	245,373,000		219,116,000
Sales revenues				(52,910,000)		(32,434,000)
Operating Segments [Member] | Enviroplex [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Revenues				17,893,000		32,237,000
Inter-segment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales revenues						$ 0
Type of Revenue [Extensible List]						us-gaap:ProductMember
Inter-segment Eliminations [Member] | Mobile Modular [Member]
Segment Reporting Information [Line Items]
Sales revenues				$ 1,277,000
Type of Revenue [Extensible List]				us-gaap:ProductMember

[1] Gross Enviroplex sales revenues were $17,893 and $32,237 for the nine months ended September 30, 2020 and 2019, respectively. There were $1,277 inter-segment sales to Mobile Modular in the nine months ended September 30, 2020, which required elimination in consolidation.  There were no inter-segment sales in the nine months ended September 30, 2019.