Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 08, 2020
Class of Stock [Line Items]
Entity Registrant Name	Griffin Capital Essential Asset REIT, Inc.
Entity Central Index Key	0001600626
Document Type	10-Q
Document Period End Date	Mar. 31, 2020
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Common Class T
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		554,112
Common Class S
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		1,802
Common Class D
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		40,585
Common Class I
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		1,890,912
Common Class A
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		24,245,556
Common Class AA
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		47,108,812
Common Class AAA
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		915,611
Common Class E
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		155,120,500