DOCUMENT AND ENTITY INFORMATION - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Mar. 12, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Entity Registrant Name	Green Bancorp, Inc.
Trading Symbol	gnbc
Entity Central Index Key	0001606363
Document Type	10-K
Amendment Flag	false
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Current Fiscal Year End Date	--12-31
Document Period End Date	Dec. 31, 2017
Document Fiscal Period Focus	FY
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Document Fiscal Year Focus	2017
Entity Common Stock, Shares Outstanding		37,189,901
Entity Public Float			$ 406.3