Segment Reporting - Summarized Financial Information for Company's Reportable Segments (Parenthetical) (Detail) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Revenues		$ 109,582,000	$ 103,105,000	$ 204,419,000	$ 196,804,000
Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues	[1]			4,911,000	4,147,000
Mobile Modular [Member]
Segment Reporting Information [Line Items]
Revenues				104,941,000	94,763,000
Operating Segments [Member] | Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues				4,911,000	4,147,000
Inter-segment Eliminations [Member] | Mobile Modular [Member]
Segment Reporting Information [Line Items]
Sales revenues				$ 0	$ 0

[1] Gross Enviroplex sales revenues were $4,911 and $4,147 for the six months ended June 30, 2017 and 2016, respectively, with no inter-segment sales to Mobile Modular requiring elimination in consolidation.