Segment Reporting (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 24, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Revenues:
Revenues		$ 149,707	$ 136,636	$ 432,360	$ 386,853
Costs and expenses:
Restructuring expenses			625	1,306	2,062	$ 2,886
Asset impairment charge and loss on divestiture, net	$ 98,278	98,278		98,278
Depreciation and amortization		16,191	15,935	50,206	46,941
Total costs and expenses		211,003	109,824	435,748	313,996
(Loss) income from operations		(61,296)	26,812	(3,388)	72,857
Interest expense, net of interest income		10,487	9,199	30,173	26,392
Income tax (benefit) provision		(19,594)	6,383	(11,182)	16,279
Capital expenditures for additions to rental fleet, excluding acquisitions		27,144	22,918	65,620	45,945
Storage Solutions
Revenues:
Revenues		120,375	111,632	347,477	315,961
Costs and expenses:
Restructuring expenses			500	1,306	1,933
Asset impairment charge and loss on divestiture, net		96,092		96,092
Depreciation and amortization		9,758	9,836	31,398	28,496
Total costs and expenses		182,197	85,008	355,739	242,788
(Loss) income from operations		(61,822)	26,624	(8,262)	73,173
Interest expense, net of interest income		7,789	6,495	22,074	18,274
Income tax (benefit) provision		(17,153)	7,261	(7,607)	19,222
Capital expenditures for additions to rental fleet, excluding acquisitions		19,533	21,138	45,205	40,870
Storage Solutions | North America
Revenues:
Revenues		97,344	89,026	279,676	251,842
Costs and expenses:
Restructuring expenses			500	1,306	1,933
Asset impairment charge and loss on divestiture, net		87,658		87,658
Depreciation and amortization		7,892	8,052	25,349	23,316
Total costs and expenses		156,390	68,536	294,896	195,098
(Loss) income from operations		(59,046)	20,490	(15,220)	56,744
Interest expense, net of interest income		7,589	6,370	21,443	17,897
Income tax (benefit) provision		(16,699)	6,280	(8,876)	16,593
Capital expenditures for additions to rental fleet, excluding acquisitions		18,290	16,629	39,400	31,833
Storage Solutions | United Kingdom
Revenues:
Revenues		23,031	22,606	67,801	64,119
Costs and expenses:
Asset impairment charge and loss on divestiture, net		8,434		8,434
Depreciation and amortization		1,866	1,784	6,049	5,180
Total costs and expenses		25,807	16,472	60,843	47,690
(Loss) income from operations		(2,776)	6,134	6,958	16,429
Interest expense, net of interest income		200	125	631	377
Income tax (benefit) provision		(454)	981	1,269	2,629
Capital expenditures for additions to rental fleet, excluding acquisitions		1,243	4,509	5,805	9,037
Tank & Pump Solutions Segment
Revenues:
Revenues		29,332	25,004	84,883	70,892
Costs and expenses:
Restructuring expenses			125		129
Asset impairment charge and loss on divestiture, net		2,186		2,186
Depreciation and amortization		6,433	6,099	18,808	18,445
Total costs and expenses		28,806	24,816	80,009	71,208
(Loss) income from operations		526	188	4,874	(316)
Interest expense, net of interest income		2,698	2,704	8,099	8,118
Income tax (benefit) provision		(2,441)	(878)	(3,575)	(2,943)
Capital expenditures for additions to rental fleet, excluding acquisitions		7,611	1,780	20,415	5,075
Rental
Revenues:
Revenues		140,924	127,695	406,149	360,288
Rental | Storage Solutions
Revenues:
Revenues		112,639	104,488	325,293	293,780
Rental | Storage Solutions | North America
Revenues:
Revenues		92,241	84,249	264,227	236,326
Rental | Storage Solutions | United Kingdom
Revenues:
Revenues		20,398	20,239	61,066	57,454
Rental | Tank & Pump Solutions Segment
Revenues:
Revenues		28,285	23,207	80,856	66,508
Sales
Revenues:
Revenues		8,716	8,438	25,700	24,817
Costs and expenses:
Cost of sales		5,770	5,519	16,925	16,039
Sales | Storage Solutions
Revenues:
Revenues		7,696	6,743	21,785	20,763
Costs and expenses:
Cost of sales		5,226	4,477	14,695	13,808
Sales | Storage Solutions | North America
Revenues:
Revenues		5,103	4,503	15,211	14,407
Costs and expenses:
Cost of sales		3,178	2,657	9,401	8,727
Sales | Storage Solutions | United Kingdom
Revenues:
Revenues		2,593	2,240	6,574	6,356
Costs and expenses:
Cost of sales		2,048	1,820	5,294	5,081
Sales | Tank & Pump Solutions Segment
Revenues:
Revenues		1,020	1,695	3,915	4,054
Costs and expenses:
Cost of sales		544	1,042	2,230	2,231
Other
Revenues:
Revenues		67	503	511	1,748
Other | Storage Solutions
Revenues:
Revenues		40	401	399	1,418
Other | Storage Solutions | North America
Revenues:
Revenues			274	238	1,109
Other | Storage Solutions | United Kingdom
Revenues:
Revenues		40	127	161	309
Other | Tank & Pump Solutions Segment
Revenues:
Revenues		27	102	112	330
Rental Selling and General Expenses
Costs and expenses:
Cost of sales		90,764	87,745	269,033	248,954
Rental Selling and General Expenses | Storage Solutions
Costs and expenses:
Cost of sales		71,121	70,195	212,248	198,551
Rental Selling and General Expenses | Storage Solutions | North America
Costs and expenses:
Cost of sales		57,662	57,327	171,182	161,122
Rental Selling and General Expenses | Storage Solutions | United Kingdom
Costs and expenses:
Cost of sales		13,459	12,868	41,066	37,429
Rental Selling and General Expenses | Tank & Pump Solutions Segment
Costs and expenses:
Cost of sales		$ 19,643	$ 17,550	$ 56,785	$ 50,403