Implemented Accounting Pronouncements - Summary of Disaggregates the Company's Revenue by Lease and Non Lease (Detail) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation Of Revenue [Line Items]
Leasing revenues										$ 401,681	$ 367,485	$ 347,247
Total non-lease revenues										96,649	94,549	76,833
Total revenues		$ 133,115	$ 143,147	$ 116,983	$ 105,085	$ 122,227	$ 135,388	$ 109,582	$ 94,837	498,330	462,034	424,080
Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues										365,212	331,218	315,089
Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										41,753	40,011	36,910
Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										89,452	89,302	70,503
Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										1,913	1,503	1,578
Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										133,118	130,816	108,991
Mobile Modular [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										40,742	38,234	29,810
Total revenues										254,574	231,266	209,512
Mobile Modular [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues										200,214	180,612	168,787
Mobile Modular [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										14,870	13,331	11,326
Mobile Modular [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										39,467	37,434	29,393
Mobile Modular [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										23	(111)	6
Mobile Modular [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										54,360	50,654	40,725
TRS-RenTelco [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										25,420	22,374	23,464
Total revenues										118,657	108,044	108,617
TRS-RenTelco [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues										94,345	85,930	87,085
TRS-RenTelco [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										2,607	2,358	2,292
TRS-RenTelco [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										19,895	18,137	17,675
TRS-RenTelco [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										1,810	1,619	1,565
TRS-RenTelco [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										24,312	22,114	21,532
Adler Tanks [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										1,441	2,572	1,438
Total revenues										96,053	91,355	83,830
Adler Tanks [Member] | Leasing [Member]
Disaggregation Of Revenue [Line Items]
Leasing revenues										70,653	64,676	59,217
Adler Tanks [Member] | Non-lease Rental Related Services [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										24,276	24,322	23,292
Adler Tanks [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										1,044	2,362	1,314
Adler Tanks [Member] | Non-lease Other [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										80	(5)	7
Adler Tanks [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										25,400	26,679	24,613
Enviroplex [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues	[1]									29,046	31,369	22,121
Total revenues	[1]									29,046	31,369	22,121
Enviroplex [Member] | Non-lease Sales [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										29,046	31,369	22,121
Enviroplex [Member] | Non-lease Revenues [Member]
Disaggregation Of Revenue [Line Items]
Total non-lease revenues										$ 29,046	$ 31,369	$ 22,121

[1] Gross Enviroplex sales revenues were $30,407, $31,369 and $22,206 in 2018, 2017 and 2016, respectively. There were $1,361 and $85 inter-segment sales to Mobile Modular in 2018 and 2016, respectively, which have been eliminated in consolidation. There were no inter-segment sales in 2017.