BASIS OF PRESENTATION (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017		Jun. 30, 2018	Jun. 30, 2017
Noninterest income
Loan and service fees	$ 2,421	$ 251	[1]	$ 4,214	$ 471	[1]
Other income	216	659	[1]	1,255	1,168	[1]
Total	9,693	8,791	[1]	19,572	17,050	[1]
Noninterest expense
Data processing fees and supplies	2,290	1,974		4,803	3,990
Total	20,274	19,352		41,476	39,400
Net Impact	347			1,050
Net income	20,142	15,364		38,478	29,878
Comprehensive income	$ 18,420	$ 17,635		$ 29,679	$ 32,634
Basic earnings per share	$ 0.8	$ 0.61		$ 1.52	$ 1.19
Diluted earnings per share	$ 0.78	$ 0.6		$ 1.5	$ 1.17
Adjustments for New Accounting Principle, Early Adoption [Member]
Noninterest income
Loan and service fees	$ 2,231			$ 4,598
Other income	344			1,255
Total	2,575			5,853
Noninterest expense
Data processing fees and supplies	2,228			4,803
Total	2,228			4,803
Net Impact	347			1,050
Net income	20,142			38,478
Comprehensive income	$ 18,420			$ 29,679
Basic earnings per share	$ 0.8			$ 1.52
Diluted earnings per share	$ 0.78			$ 1.50
Accounting Standards Update 2016-09 [Member]
Noninterest income
Loan and service fees	$ 190			$ 384
Other income	(128)			(128)
Total	62			256
Noninterest expense
Data processing fees and supplies	62			256
Total	62			256
Net Impact	0			0
Net income	0			0
Comprehensive income	$ 0			$ 0
Basic earnings per share	$ 0			$ 0
Diluted earnings per share	$ 0			$ 0

[1] The Company elected the modified retrospective approach of adoption; therefore, prior period balances are presented under legacy GAAP and may not be comparable to current year presentation. As a result of this new standard, the only revenue streams with changes in reporting in the current periods compared to the prior year comparable periods are loan and service fees and other income.