Parent Company Only Financial Statements - Condensed Statements of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 14,742us-gaap_NetIncomeLoss	$ 12,610us-gaap_NetIncomeLoss	$ 8,535us-gaap_NetIncomeLoss
Adjustments to reconcile net income to net cash provided (used) by operating activities:
Deferred income tax benefit	395us-gaap_DeferredIncomeTaxExpenseBenefit	(540)us-gaap_DeferredIncomeTaxExpenseBenefit	(687)us-gaap_DeferredIncomeTaxExpenseBenefit
Decrease (increase) in other assets, net	(1,061)	1,433	(8)
Increase (decrease) in other liabilities, net	138	475	1,462
Net Cash Provided by (Used in) Operating Activities, Continuing Operations, Total	19,807	14,801	19,327
CASH FLOWS FROM INVESTING ACTIVITIES:
Net cash used in investing activities	(182,256)	(176,106)	(276,932)
CASH FLOWS FROM FINANCING ACTIVITIES:
Common stock issued in connection with the exercise of stock options	117	190
Net cash provided by (used in) financing activities	196,615	17,570	284,907
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	34,166	(143,735)	27,302
CASH AND CASH EQUIVALENTS:
Beginning of year	34,757	178,492	151,190
End of period	68,923	34,757	178,492
Green Bancorp, Inc.
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	14,743	12,610	8,535
Adjustments to reconcile net income to net cash provided (used) by operating activities:
EQUITY IN UNDISTRIBUTED EARNINGS OF SUBSIDIARY, Net of tax	15,957	13,253	9,079
Deferred income tax benefit	17	14	17
Decrease (increase) in other assets, net	332	64	(25)
Increase (decrease) in other liabilities, net	34	9	(5)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations, Total	(1,495)	(684)	(507)
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital contributed to subsidiary	(67,508)		(25,000)
Net cash used in investing activities	(67,508)		(25,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of issuance expenses	72,591		24,734
Common stock issued in connection with the exercise of stock options	125	190
Net cash provided by (used in) financing activities	72,716	190	24,734
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	3,713	(494)	(773)
CASH AND CASH EQUIVALENTS:
Beginning of year	4,953	5,447	6,220
End of period	$ 8,666	$ 4,953	$ 5,447

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