FAIR VALUE DISCLOSURES - Summary of Financial Assets and Liabilities Measure at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets
Derivatives	$ 28,522	$ 14,025
Investment securities available-for-sale	1,120,494	1,190,642
Liabilities
Derivatives	28,657	14,179
Fair Value, Measurements, Recurring
Assets
Derivatives	28,835	14,111
Investment securities available-for-sale	1,120,494	1,190,642
Total	1,149,329	1,204,753
Liabilities
Derivatives	28,756	14,243
Fair Value, Measurements, Recurring | Fair Value Measurements Using Level 1
Assets
Derivatives	0	0
Investment securities available-for-sale	8,905	8,583
Total	8,905	8,583
Liabilities
Derivatives	0	0
Fair Value, Measurements, Recurring | Fair Value Measurements Using Level 2
Assets
Derivatives	28,835	14,111
Investment securities available-for-sale	1,111,589	1,182,059
Total	1,140,424	1,196,170
Liabilities
Derivatives	28,756	14,243
Fair Value, Measurements, Recurring | Fair Value Measurements Using Level 3
Assets
Derivatives	0	0
Investment securities available-for-sale	0	0
Total	0	0
Liabilities
Derivatives	$ 0	$ 0