Implemented Accounting Pronouncements - Summary of Disaggregates the Company's Revenue by Lease and Non Lease (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018		Sep. 30, 2017
Disaggregation Of Revenue [Line Items]
Leasing revenues		$ 106,035	$ 95,637	$ 294,480		$ 270,299
Total non-lease revenues				70,735		69,508
Total revenues		143,147	135,388	365,215		339,807
Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues		94,184	84,557	267,744		242,919
Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		13,120	12,406	30,716		30,229
Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		35,364	37,961	65,333		65,345
Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		479	464	1,422		1,314
Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		48,963	50,831	97,471		96,888
Mobile Modular [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues				31,667		30,622
Total revenues		74,891	68,887	188,613		173,828
Mobile Modular [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues		52,036	45,824	146,672		133,184
Mobile Modular [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		5,697	5,528	11,226		10,634
Mobile Modular [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		17,140	17,533	30,694		30,001
Mobile Modular [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		18	2	21		9
Mobile Modular [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		22,855	23,063	41,941		40,644
TRS-RenTelco [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues				18,321		16,493
Total revenues		28,137	27,304	86,527		79,157
TRS-RenTelco [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues		23,206	22,033	69,183		63,106
TRS-RenTelco [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		642	623	1,816		1,666
TRS-RenTelco [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		3,828	4,186	14,179		13,080
TRS-RenTelco [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		461	462	1,349		1,305
TRS-RenTelco [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		4,931	5,271	17,344		16,051
Adler Tanks [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues				916		1,701
Total revenues		26,017	23,416	70,244		66,130
Adler Tanks [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues		18,942	16,700	51,889		46,629
Adler Tanks [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		6,781	6,255	17,674		17,929
Adler Tanks [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		294	461	629		1,572
Adler Tanks [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues				52
Adler Tanks [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		7,075	6,716	18,355		19,501
Enviroplex [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues	[1]			19,831		20,692
Total revenues		14,102	15,781	19,831	[1]	20,692	[1]
Enviroplex [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		14,102	15,781	19,831		20,692
Enviroplex [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues		$ 14,102	$ 15,781	$ 19,831		$ 20,692

[1] Gross Enviroplex sales revenues were $21,191 and $20,692 for the nine months ended September 30, 2018 and 2017, respectively. There were $1,360 inter-segment sales to Mobile Modular in the nine months ended September 30, 2018, which required elimination in consolidation. There were no inter-segment sales in the nine months ended September 30, 2017.