Segment Reporting - Summarized Financial Information for Company's Reportable Segments (Parenthetical) (Detail) - USD ($)		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenues		$ 105,085,000	$ 94,837,000
Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues	[1]	2,018,000	759,000
Mobile Modular [Member]
Segment Reporting Information [Line Items]
Revenues		53,851,000	48,303,000
Operating Segments [Member] | Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues		2,813,000	759,000
Inter-segment Eliminations [Member]
Segment Reporting Information [Line Items]
Sales revenues			$ 0
Inter-segment Eliminations [Member] | Mobile Modular [Member]
Segment Reporting Information [Line Items]
Sales revenues		$ 795,000

[1] Gross Enviroplex sales revenues were $2,813 and $759 for the three months ended March 31, 2018 and 2017, respectively. There were $795 inter-segment sales to Mobile Modular in the three months ended March 31, 2018 requiring elimination in consolidation. There were no inter-segment sales in the three months ended March 31, 2017.