FAIR VALUE MEASUREMENTS (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Assets and financial liabilities measured at fair value on a recurring basis
Trading security	$ 14,909	$ 14,840
Available-for-sale securities	1,091,818	760,048
Debt securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	1,036,876	738,075
Debt securities | Municipal bonds and obligations
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	133,699	77,671
Debt securities | Government guaranteed residential mortgage-backed securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	69,468	78,771
Debt securities | Government-sponsored residential mortgage-backed securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	760,184	522,658
Debt securities | Corporate bonds
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	54,151	39,280
Debt securities | Trust preferred securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	16,215	16,611
Debt securities | Other bonds and obligations
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	3,159	3,084
Marketable equity securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	54,942	21,973
Total Fair Value
Assets and financial liabilities measured at fair value on a recurring basis
Trading security	14,909	14,840
Available-for-sale securities	1,091,818	760,048
Loans held for sale	19,493	15,840
Derivative assets	12,953	8,318
Derivative liabilities	18,769	11,964
Level 1
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	53,806	20,891
Derivative assets		242
Derivative liabilities	417
Level 2
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	1,035,686	737,193
Loans held for sale	19,493	15,840
Derivative assets	12,328	7,799
Derivative liabilities	18,259	11,964
Level 3
Assets and financial liabilities measured at fair value on a recurring basis
Trading security	14,909	14,840
Available-for-sale securities	2,326	1,964
Derivative assets	625	277
Derivative liabilities	93
Level 3 | Trust preferred securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	1,500
Recurring
Assets and financial liabilities measured at fair value on a recurring basis
Transfers between Level 1, 2, and 3	0	0
Recurring | Total Fair Value
Assets and financial liabilities measured at fair value on a recurring basis
Trading security	14,909	14,840
Loans held for sale	19,493	15,840
Derivative assets	12,953	8,318
Derivative liabilities	18,769	11,964
Recurring | Total Fair Value | Debt securities | Municipal bonds and obligations
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	133,699	77,671
Recurring | Total Fair Value | Debt securities | Government guaranteed residential mortgage-backed securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	69,468	78,771
Recurring | Total Fair Value | Debt securities | Government-sponsored residential mortgage-backed securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	760,184	522,658
Recurring | Total Fair Value | Debt securities | Corporate bonds
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	54,151	39,280
Recurring | Total Fair Value | Debt securities | Trust preferred securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	16,215	16,611
Recurring | Total Fair Value | Debt securities | Other bonds and obligations
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	3,159	3,084
Recurring | Total Fair Value | Marketable equity securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	54,942	21,973
Recurring | Level 1
Assets and financial liabilities measured at fair value on a recurring basis
Derivative assets		242
Derivative liabilities	417
Recurring | Level 1 | Marketable equity securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	53,806	20,891
Recurring | Level 2
Assets and financial liabilities measured at fair value on a recurring basis
Loans held for sale	19,493	15,840
Derivative assets	12,328	7,799
Derivative liabilities	18,259	11,964
Recurring | Level 2 | Debt securities | Municipal bonds and obligations
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	133,699	77,671
Recurring | Level 2 | Debt securities | Government guaranteed residential mortgage-backed securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	69,468	78,771
Recurring | Level 2 | Debt securities | Government-sponsored residential mortgage-backed securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	760,184	522,658
Recurring | Level 2 | Debt securities | Corporate bonds
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	54,151	39,280
Recurring | Level 2 | Debt securities | Trust preferred securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	14,667	15,372
Recurring | Level 2 | Debt securities | Other bonds and obligations
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	3,159	3,084
Recurring | Level 2 | Marketable equity securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	358	357
Recurring | Level 3
Assets and financial liabilities measured at fair value on a recurring basis
Trading security	14,909	14,840
Derivative assets	625	277
Derivative liabilities	93
Recurring | Level 3 | Debt securities | Trust preferred securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	1,548	1,239
Recurring | Level 3 | Marketable equity securities
Assets and financial liabilities measured at fair value on a recurring basis
Available-for-sale securities	$ 778	$ 725