LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Internal risk-rating categories for the Company's commercial portfolio
Total	$ 3,077,026	$ 2,630,783
Pass [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	2,825,056	2,340,719
Potential weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	118,479	169,874
Definite weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	129,627	116,295
Parital loss probable [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	3,864	3,895
Definite loss [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total
Commercial and Industrial [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	687,511	575,716
Commercial and Industrial [Member] | Pass [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	647,984	528,798
Commercial and Industrial [Member] | Potential weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	16,420	33,313
Commercial and Industrial [Member] | Definite weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	21,979	12,683
Commercial and Industrial [Member] | Parital loss probable [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	1,128	922
Commercial and Industrial [Member] | Definite loss [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total
Commercial Real Estate [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	2,122,153	1,847,654
Commercial Real Estate [Member] | Pass [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	1,928,148	1,626,745
Commercial Real Estate [Member] | Potential weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	92,651	124,661
Commercial Real Estate [Member] | Definite weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	98,688	93,438
Commercial Real Estate [Member] | Parital loss probable [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	2,666	2,810
Commercial Real Estate [Member] | Definite loss [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total
Commercial Construction [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	188,768	128,904
Commercial Construction [Member] | Pass [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	177,693	114,633
Commercial Construction [Member] | Potential weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	6,195	7,859
Commercial Construction [Member] | Definite weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	4,880	6,412
Commercial Construction [Member] | Parital loss probable [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total
Commercial Construction [Member] | Definite loss [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total
Small Business [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	78,594	78,509
Small Business [Member] | Pass [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	71,231	70,543
Small Business [Member] | Potential weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	3,213	4,041
Small Business [Member] | Definite weakness [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	4,080	3,762
Small Business [Member] | Parital loss probable [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total	70	163
Small Business [Member] | Definite loss [Member]
Internal risk-rating categories for the Company's commercial portfolio
Total