FAIR VALUE - Summary of Carrying Value and Fair Value of Company's Financial Instruments (Details) - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity		$ 198,231	$ 203,525
Loans, net		2,435,490	2,137,202
Quoted Prices in Active Markets for Identical Assets Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	0	0
Loans, net		0	0
Deposit liabilities		0	0
Borrowings		0	0
Subordinated debt		0	0
Significant Other Observable Inputs Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	198,820	202,813
Loans, net		0	0
Deposit liabilities		0	0
Borrowings		51,778	51,788
Subordinated debt		52,785	52,785
Significant Unobservable Inputs Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	0	0
Loans, net		2,454,731	2,147,024
Deposit liabilities		3,222,077	2,843,800
Borrowings		0	0
Subordinated debt		0	0
Carrying Amount [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities held to maturity	[1]	198,231	203,525
Loans, net		2,429,961	2,129,691
Deposit liabilities		3,222,447	2,844,387
Borrowings		50,000	50,000
Subordinated debt		$ 70,031	$ 69,891

[1] See Note D for further detail of fair value of individual investment categories.