Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 29, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	MGRC
Entity Registrant Name	MCGRATH RENTCORP
Entity Central Index Key	0000752714
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity File Number	0-13292
Entity Tax Identification Number	942579843
Entity Address, Address Line One	5700 Las Positas Road
Entity Address, City or Town	Livermore
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94551-7800
City Area Code	925
Local Phone Number	606-9200
Entity Common Stock, Shares Outstanding		24,253,091