Goodwill - Goodwill Activity (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 1,171,219	$ 235,177
Acquisition of Mobile Mini		928,974
Changes to Mobile Mini purchase accounting	8,161
Effects of movements in foreign exchange rates	1,357	7,068
Goodwill, end of period	1,180,737	1,171,219
NA Modular
Goodwill [Roll Forward]
Goodwill, beginning of period	235,828	235,177
Acquisition of Mobile Mini		0
Changes to Mobile Mini purchase accounting	285,000
Effects of movements in foreign exchange rates	842	651
Goodwill, end of period	521,670	235,828
NA Storage
Goodwill [Roll Forward]
Goodwill, beginning of period	726,529	0
Acquisition of Mobile Mini		726,529
Changes to Mobile Mini purchase accounting	(233,666)
Effects of movements in foreign exchange rates	(293)	0
Goodwill, end of period	492,570	726,529
UK Storage
Goodwill [Roll Forward]
Goodwill, beginning of period	65,600	0
Acquisition of Mobile Mini		59,183
Changes to Mobile Mini purchase accounting	0
Effects of movements in foreign exchange rates	808	6,417
Goodwill, end of period	66,408	65,600
Tank and Pump
Goodwill [Roll Forward]
Goodwill, beginning of period	143,262	0
Acquisition of Mobile Mini		143,262
Changes to Mobile Mini purchase accounting	(43,173)
Effects of movements in foreign exchange rates	0	0
Goodwill, end of period	$ 100,089	$ 143,262

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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