Revenue Recognition - Summary of Disaggregates the Company's Revenue by Lease and Non Lease (Detail) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Leasing revenues										$ 401,900
Total non-lease revenues										128,371	$ 115,303	$ 96,649
Total revenues		$ 148,980	$ 156,448	$ 137,673	$ 129,453	$ 147,221	$ 173,562	$ 127,439	$ 122,008	572,554	570,230	498,330
Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues										401,923	410,993	365,212
Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										46,514	49,197	41,753
Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										122,447	107,120	89,452
Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										1,670	2,920	1,913
Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										170,631	159,237	133,118
Mobile Modular [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										65,278	49,299	40,742
Total revenues										321,524	301,010	254,574
Mobile Modular [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues										235,003	234,032	200,214
Mobile Modular [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										22,576	18,964	14,870
Mobile Modular [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										63,863	47,045	39,467
Mobile Modular [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										82	969	23
Mobile Modular [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										86,521	66,978	54,360
TRS-RenTelco [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										28,648	24,519	25,420
Total revenues										140,811	131,483	118,657
TRS-RenTelco [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues										112,210	108,044	94,345
TRS-RenTelco [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										2,618	2,599	2,607
TRS-RenTelco [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										24,461	18,995	19,895
TRS-RenTelco [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										1,522	1,845	1,810
TRS-RenTelco [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										28,601	23,439	24,312
Adler Tanks [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										1,708	1,671	1,441
Total revenues										77,482	97,923	96,053
Adler Tanks [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues										54,710	68,917	70,653
Adler Tanks [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										21,320	27,634	24,276
Adler Tanks [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										1,386	1,266	1,044
Adler Tanks [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										66	106	80
Adler Tanks [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										22,772	29,006	25,400
Enviroplex [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues	[1]									32,737	39,814	29,046
Total revenues	[1]									32,737	39,814	29,046
Enviroplex [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										32,737	39,814	29,046
Enviroplex [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										$ 32,737	$ 39,814	$ 29,046

[1] Gross Enviroplex sales revenues were $34,014, $39,814 and $30,407 in 2020, 2019 and 2018, respectively.  There were $1,277 and $1,361 inter-segment sales to Mobile Modular in 2020 and 2018, which have been eliminated in consolidation.  There were no inter-segment sales in 2019.