Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	Apr. 24, 2020
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Entity Registrant Name	MOBILE MINI INC
Entity Central Index Key	0000911109
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding		44,359,914
Entity File Number	1-12804
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	86-0748362
Entity Address, Address Line One	4646 E. Van Buren Street
Entity Address, Address Line Two	Suite 400
Entity Address, City or Town	Phoenix
Entity Address, State or Province	AZ
Entity Address, Postal Zip Code	85008
City Area Code	480
Local Phone Number	894-6311
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Common Stock
Document Information [Line Items]
Security 12b Title	Common Stock, $.01 par value
Trading Symbol	MINI
Security Exchange Name	NASDAQ
Preferred Stock
Document Information [Line Items]
Security 12b Title	Preferred Share Purchase Rights
No Trading Symbol Flag	true