Segment Reporting - Summarized Financial Information for Company's Reportable Segments (Parenthetical) (Detail) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018		Jun. 30, 2017
Segment Reporting Information [Line Items]
Revenues		$ 116,983,000	$ 109,582,000	$ 222,068,000		$ 204,419,000
Sales revenues				(33,623,000)		(29,757,000)
Sales [Member]
Segment Reporting Information [Line Items]
Sales revenues		(19,546,000)	(20,187,000)	(31,637,000)		(28,482,000)
Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues		3,711,000	4,152,000	5,729,000	[1]	4,911,000	[1]
Sales revenues	[1]			(5,729,000)		(4,911,000)
Mobile Modular [Member]
Segment Reporting Information [Line Items]
Revenues		$ 59,871,000	$ 56,638,000	113,722,000		104,941,000
Sales revenues				(14,169,000)		(12,703,000)
Operating Segments [Member] | Enviroplex [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Revenues				6,524,000		4,911,000
Inter-segment Eliminations [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Sales revenues						$ 0
Inter-segment Eliminations [Member] | Mobile Modular [Member] | Sales [Member]
Segment Reporting Information [Line Items]
Sales revenues				$ 795,000

[1] Gross Enviroplex sales revenues were $6,524 and $4,911 for the six months ended June 30, 2018 and 2017, respectively. There were $795 inter-segment sales to Mobile Modular in the six months ended June 30, 2018, which required elimination in consolidation. There were no inter-segment sales in the six months ended June 30, 2017.