Segment Reporting - Summarized Financial Information for Company's Reportable Segments (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 90,188	$ 87,560
Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues	312	1,105
Mobile Modular [Member]
Segment Reporting Information [Line Items]
Revenues	38,884	33,640
Operating Segments [Member] | Enviroplex [Member]
Segment Reporting Information [Line Items]
Revenues	316	1,105
Inter-segment Eliminations [Member] | Mobile Modular [Member]
Segment Reporting Information [Line Items]
Sales revenues	$ 4	$ 0