INCOME TAXES (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Computed statutory federal income tax provision									$ 29,310	$ 23,359	$ 20,055
State taxes, net of federal tax benefit									4,104	3,455	2,553
Nontaxable interest, net									(795)	(557)	(542)
New Market Tax Credits									(6,708)	(9,000)	(6,371)
Low Income Housing Project Investments									594	194	196
Increase in cash surrender value of life insurance and tax exempt gain on benefit payments									(1,782)	(1,209)	(1,612)
Merger and other related costs (non-deductible)									274	366	404
Other, net									90	264	382
Total expense	$ 6,201	$ 6,415	$ 5,934	$ 5,350	$ 2,786	$ 5,299	$ 4,285	$ 4,114	$ 23,899	$ 16,484	$ 14,673
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Computed statutory federal income tax provision									35.00%	35.00%	35.00%
State taxes, net of federal tax benefit									4.90%	5.17%	4.46%
Nontaxable interest, net									(0.95%)	(0.83%)	(0.95%)
New Market Tax Credits									(8.01%)	(13.48%)	(11.12%)
Low Income Housing Project Investments									(0.71%)	(0.29%)	(0.34%)
Increase in cash surrender value of life insurance and tax exempt gain on benefit payments									(2.13%)	(1.81%)	(2.81%)
Merger and other related costs (non-deductible)									0.33%	0.55%	0.71%
Other, net									0.11%	0.39%	0.66%
Total expense									28.54%	24.70%	25.61%