FAIR VALUE MEASUREMENTS (Details 4) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015		Mar. 31, 2015	Dec. 31, 2014
Financial assets:
Cash and cash equivalents	$ 110,815	$ 111,918		$ 108,502	$ 132,365
Investment securities	1,103,444	689,132	[1]
Investment securities held to maturity	39,071	39,182	[1]
Loans held for sale	53,820	47,287	[1]
Loans, net	5,198,521	3,066,775	[1]
Purchased accounts receivable	57,175	52,688	[1]
Federal Home Loan Bank stock	41,851	24,844	[1]
Derivative assets	1,808	996
Accrued interest receivable	19,812	12,695
Financial liabilities:
Deposits	5,349,712	3,310,297	[1]
Short-term borrowings	761,243	375,500	[1]
Long-term debt	198,320	194,967	[1]
Derivative liabilities	9,212	4,376
Accrued interest payable	2,191	2,550
Level 1
Financial assets:
Cash and cash equivalents, Fair Value	110,815	111,918
Investment securities	27,728	16,532
Investment securities held to maturity, Fair Value	0	0
Loans held for sale, Fair Value	0	0
Loans held for investment, Fair Value	0	0
Purchased accounts receivable	0	0
Federal Home Loan Bank stock, at cost	0	0
Derivative assets	0	0
Accrued interest receivable, Fair Value	0	0
Financial liabilities:
Deposits, Fair Value	0	0
Short term borrowings, Fair Value	0	0
Long-term debt, Fair Value	0	0
Derivative liabilities, Fair Value	0	0
Accrued interest payable, Fair Value	0	0
Level 2
Financial assets:
Cash and cash equivalents, Fair Value	0	0
Investment securities	1,069,222	665,872
Investment securities held to maturity, Fair Value	40,682	40,500
Loans held for sale, Fair Value	53,820	47,287
Loans held for investment, Fair Value	40,630	23,664
Purchased accounts receivable	57,175	52,688
Federal Home Loan Bank stock, at cost	41,851	24,844
Derivative assets	683	588
Accrued interest receivable, Fair Value	19,812	12,695
Financial liabilities:
Deposits, Fair Value	5,354,109	3,310,306
Short term borrowings, Fair Value	0	0
Long-term debt, Fair Value	0	0
Derivative liabilities, Fair Value	9,212	4,376
Accrued interest payable, Fair Value	2,191	2,550
Level 3
Financial assets:
Cash and cash equivalents, Fair Value	0	0
Investment securities	6,494	6,728
Investment securities held to maturity, Fair Value	0	0
Loans held for sale, Fair Value	0	0
Loans held for investment, Fair Value	5,213,479	3,068,797
Purchased accounts receivable	0	0
Federal Home Loan Bank stock, at cost	0	0
Derivative assets	1,125	408
Accrued interest receivable, Fair Value	0	0
Financial liabilities:
Deposits, Fair Value	0	0
Short term borrowings, Fair Value	761,243	375,500
Long-term debt, Fair Value	204,279	198,928
Derivative liabilities, Fair Value	0	0
Accrued interest payable, Fair Value	0	0
Estimate of Fair Value Measurement
Financial assets:
Cash and cash equivalents, Fair Value	110,815	111,918
Investment securities	1,103,444	689,132
Investment securities held to maturity, Fair Value	40,682	40,500
Loans held for sale, Fair Value	53,820	47,287
Loans held for investment, Fair Value	5,254,109	3,092,461
Purchased accounts receivable	57,175	52,688
Federal Home Loan Bank stock, at cost	41,851	24,844
Derivative assets	1,808	996
Accrued interest receivable, Fair Value	19,812	12,695
Financial liabilities:
Deposits, Fair Value	5,354,109	3,310,306
Short term borrowings, Fair Value	761,243	375,500
Long-term debt, Fair Value	204,279	198,928
Derivative liabilities, Fair Value	9,212	4,376
Accrued interest payable, Fair Value	$ 2,191	$ 2,550

[1] Derived from the audited consolidated financial statements included in the Company's 2015 Annual Report on Form 10-K.