Segment Reporting - Summarized Financial Information for Company's Reportable Segments (Parenthetical) (Detail) - USD ($)		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019		Sep. 30, 2018
Segment Reporting Information [Line Items]
Revenues		$ 173,562,000	$ 143,147,000	$ 423,009,000		$ 365,215,000
Sales revenues				(84,613,000)		(70,735,000)
Sales [Member]
Segment Reporting Information [Line Items]
Sales revenues		(50,855,000)	(36,085,000)	(81,387,000)		(67,722,000)
Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues		28,361,000	14,102,000	32,238,000	[1]	19,831,000	[1]
Sales revenues	[1]			(32,238,000)		(19,831,000)
Mobile Modular [Member]
Segment Reporting Information [Line Items]
Revenues		$ 86,302,000	$ 74,891,000	219,116,000		188,613,000
Sales revenues				(32,434,000)		(31,667,000)
Operating Segments [Member] | Enviroplex [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Revenues				32,238,000		21,191,000
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						$ 1,360,000
Type of Revenue [Extensible List]						us-gaap:ProductMember

[1] Gross Enviroplex sales revenues were $32,238 and $21,191 for the nine months ended September 30, 2019 and 2018, respectively. There were $1,360 inter-segment sales to Mobile Modular in the nine months ended September 30, 2018, which required elimination in consolidation.  There were no inter-segment sales in the nine months ended September 30, 2019.