FAIR VALUE MEASUREMENTS (Details 3) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	$ 487,076	$ 477,507
Loans and Leases Receivable, Net Amount	5,938,039	5,491,896
Securities held to maturity, fair value	485,650	478,749
Federal Home Loan Bank Stock	11,497	14,431
Bank Owned Life Insurance	144,503	134,627
Liabilities, Fair Value Disclosure [Abstract]
Advances from Federal Home Loan Banks	50,819	102,080
Customer Repurchase Agreements and other short-term borrowings	176,913	133,958
Junior subordinated debentures	73,107	73,306
Subordinated Debt	34,635	34,589
Deposits [Member]
Liabilities, Fair Value Disclosure [Abstract]
Financial Liabilities Book Value	5,763,101	5,305,873
Accrued Liabilities, Fair Value Disclosure	5,763,101	5,305,873
Bank Time Deposits [Member]
Liabilities, Fair Value Disclosure [Abstract]
Financial Liabilities Book Value	649,152	684,830
Accrued Liabilities, Fair Value Disclosure	647,038	684,370
Federal Home Loan Bank Advances [Member]
Liabilities, Fair Value Disclosure [Abstract]
Advances from Federal Home Loan Banks	50,819	102,080
Federal Home Loan Bank Borrowings, Fair Value Disclosure	50,898	102,396
Customer Repurchase Agreements [Member]
Liabilities, Fair Value Disclosure [Abstract]
Customer Repurchase Agreements and other short-term borrowings	176,913	133,958
Accrued Liabilities, Fair Value Disclosure	176,913	133,958
Junior Subordinated Debt [Member]
Liabilities, Fair Value Disclosure [Abstract]
Junior subordinated debentures	73,107	73,306
Accrued Liabilities, Fair Value Disclosure	72,510	73,871
Subordinated Debt [Member]
Liabilities, Fair Value Disclosure [Abstract]
Subordinated Debt	34,635	34,589
Accrued Liabilities, Fair Value Disclosure	34,241	34,370
Significant Other Observable Inputs (Level 2) [Member] | Deposits [Member]
Liabilities, Fair Value Disclosure [Abstract]
Accrued Liabilities, Fair Value Disclosure	5,763,101	5,305,873
Significant Other Observable Inputs (Level 2) [Member] | Bank Time Deposits [Member]
Liabilities, Fair Value Disclosure [Abstract]
Accrued Liabilities, Fair Value Disclosure	647,038	684,370
Significant Other Observable Inputs (Level 2) [Member] | Federal Home Loan Bank Advances [Member]
Liabilities, Fair Value Disclosure [Abstract]
Federal Home Loan Bank Borrowings, Fair Value Disclosure	50,898
Accrued Liabilities, Fair Value Disclosure		102,396
Significant Other Observable Inputs (Level 2) [Member] | Junior Subordinated Debt [Member]
Liabilities, Fair Value Disclosure [Abstract]
Accrued Liabilities, Fair Value Disclosure	72,510	73,871
Significant Unobservable Inputs (Level 3) [Member] | Customer Repurchase Agreements [Member]
Liabilities, Fair Value Disclosure [Abstract]
Accrued Liabilities, Fair Value Disclosure	176,913	133,958
Significant Unobservable Inputs (Level 3) [Member] | Subordinated Debt [Member]
Liabilities, Fair Value Disclosure [Abstract]
Accrued Liabilities, Fair Value Disclosure	34,241	34,370
US Treasury Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	1,007	1,009
Securities held to maturity, fair value	1,054	1,064
US Treasury Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	1,054	1,064
Agency mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	156,088	167,134
Securities held to maturity, fair value	157,504	170,375
Agency mortgage-backed securities | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	157,504	170,375
Agency collateralized mortgage obligations
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	297,445	267,348
Securities held to maturity, fair value	294,650	264,891
Agency collateralized mortgage obligations | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	294,650	264,891
State, county, and municipal securities
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities		225
Securities held to maturity, fair value		227
State, county, and municipal securities | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	0	227
Single issuer trust preferred securities issued by banks and insurers
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	1,500	1,500
Securities held to maturity, fair value	1,544	1,522
Single issuer trust preferred securities issued by banks and insurers | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	1,544	1,522
Small Business Administration Pooled Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities	31,036	35,291
Securities held to maturity, fair value	30,898	35,664
Small Business Administration Pooled Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	0	0
Small Business Administration Pooled Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	30,898	35,664
Small Business Administration Pooled Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value	0	0
Corporate Debt Securities [Member]
Assets, Fair Value Disclosure [Abstract]
Held-to-maturity Securities		5,000
Securities held to maturity, fair value		5,006
Corporate Debt Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Securities held to maturity, fair value		5,006
Loans Net Of Allowance For Loan Loses [Member]
Assets, Fair Value Disclosure [Abstract]
Loans and Leases Receivable, Net Amount	5,904,065	5,487,298
Loans, net of allowance for loan losses	5,784,778	5,417,425
Loans Net Of Allowance For Loan Loses [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure [Abstract]
Loans, net of allowance for loan losses	5,784,778	5,417,425
Investment in Federal Home Loan Bank Stock [Member]
Assets, Fair Value Disclosure [Abstract]
Federal Home Loan Bank Stock	11,497	14,431
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	11,497	14,431
Investment in Federal Home Loan Bank Stock [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure [Abstract]
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	0	0
Investment in Federal Home Loan Bank Stock [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	11,497	14,431
Investment in Federal Home Loan Bank Stock [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure [Abstract]
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	0	0
Cash Surrender Value [Member]
Assets, Fair Value Disclosure [Abstract]
Bank Owned Life Insurance	144,503	134,627
Cash Surrender Value, Fair Value Disclosure	144,503	134,627
Cash Surrender Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets, Fair Value Disclosure [Abstract]
Cash Surrender Value, Fair Value Disclosure	0	0
Cash Surrender Value [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets, Fair Value Disclosure [Abstract]
Cash Surrender Value, Fair Value Disclosure	144,503	134,627
Cash Surrender Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets, Fair Value Disclosure [Abstract]
Cash Surrender Value, Fair Value Disclosure	$ 0	$ 0