Implemented Accounting Pronouncements - Summary of Disaggregates the Company's Revenue by Lease and Non Lease (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018		Jun. 30, 2017
Disaggregation Of Revenue [Line Items]
Leasing revenues		$ 96,353	$ 88,749	$ 188,445		$ 174,662
Total non-lease revenues				33,623		29,757
Total revenues		116,983	109,582	222,068		204,419
Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues		86,747	79,299	170,301		156,499
Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		10,973	10,396	20,855		19,684
Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		18,714	19,491	29,969		27,388
Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		549	396	943		848
Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		30,236	30,283	51,767		47,920
Mobile Modular [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues				14,169		12,703
Total revenues		59,871	56,638	113,722		104,941
Mobile Modular [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues		46,634	43,562	91,905		85,960
Mobile Modular [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		4,275	3,566	8,260		6,507
Mobile Modular [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		8,961	9,504	13,554		12,468
Mobile Modular [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		1	6	3		6
Mobile Modular [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		13,237	13,076	21,817		18,981
TRS-RenTelco [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues				13,182		10,990
Total revenues		30,352	26,539	58,390		51,853
TRS-RenTelco [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues		23,136	20,588	45,636		40,805
TRS-RenTelco [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		707	654	1,514		1,312
TRS-RenTelco [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		6,012	4,909	10,351		8,894
TRS-RenTelco [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		497	388	889		842
TRS-RenTelco [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		7,216	5,951	12,754		11,048
Adler Tanks [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues				543		1,153
Total revenues		23,049	22,253	44,227		42,714
Adler Tanks [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues		16,977	15,149	32,760		29,734
Adler Tanks [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		5,991	6,176	11,081		11,865
Adler Tanks [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		30	926	335		1,115
Adler Tanks [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		51	2	51
Adler Tanks [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		6,072	7,104	11,467		12,980
Enviroplex [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues	[1]			5,729		4,911
Total revenues		3,711	4,152	5,729	[1]	4,911	[1]
Enviroplex [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		3,711	4,152	5,729		4,911
Enviroplex [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		$ 3,711	$ 4,152	$ 5,729		$ 4,911

[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.