Segment Reporting - Summarized Financial Information for Company's Reportable Segments (Parenthetical) (Detail) - USD ($)		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Revenues		$ 94,837,000	$ 93,699,000
Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues	[1]	759,000	148,000
Mobile Modular [Member]
Segment Reporting Information [Line Items]
Revenues		48,303,000	45,084,000
Operating Segments [Member] | Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues		759,000	148,000
Inter-segment Eliminations [Member] | Mobile Modular [Member]
Segment Reporting Information [Line Items]
Sales revenues		$ 0	$ 0

[1] Gross Enviroplex sales revenues were $759 and $148 for the three months ended March 31, 2017 and 2016, respectively. There were no inter-segment sales to Mobile Modular in those periods requiring elimination in consolidation.