SECURITIES (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amortized Cost, Available for sale:
Within one year	$ 15,771,000
One to five years	37,707,000
Five to ten years	122,367,000
Beyond ten years	416,822,000
Total	592,667,000	595,067,000
Fair Value, Available for sale:
Within one year	15,855,000
One to five years	37,518,000
Five to ten years	120,453,000
Beyond ten years	413,358,000
Estimated Fair Value	587,184,000	575,179,000
Amortized Cost, Held to maturity:
Within one year	17,087,000
One to five years	29,962,000
Five to ten years	56,873,000
Beyond ten years	111,005,000
Total	214,927,000	201,328,000
Fair Value, Held to maturity:
Within one year	17,139,000
One to five years	30,085,000
Five to ten years	58,386,000
Beyond ten years	110,679,000
Estimated Fair Value	216,289,000	197,339,000
Amortized Cost, Total securities
Within One Year	32,858,000
After One But Within Five Years	67,669,000
After Five But Within Ten	179,240,000
After Ten Years	527,827,000
Marketable Securities, Amortized Cost	807,594,000	796,395,000
Fair Value, Total securities
Within One Year	32,994,000
After One But Within Five Years	67,603,000
After Five But Within Ten Years	178,839,000
After Ten Years	524,037,000
Investments, Fair Value Disclosure	803,473,000	772,518,000
Other-Than-Temporary-Impairment
Proceeds from sales of securities available for sale	360,963,000	129,431,000	151,959,000
Gross losses realized on sale of securities available for sale	2,300,000	800,000	600,000
Net gains (losses) realized on sale of securities available for sale	1,200,000	1,500,000	3,200,000
Fair value of securities pledged to secure public deposits and FHLB and FRB overnight borrowings	451,100,000	397,500,000
Amount owned in FHLB, ACBB and FRB stock	10,037,000	7,034,000
U.S. GSE securities
Amortized Cost, Available for sale:
Within one year	197,000
One to five years	9,000,000
Five to ten years	88,363,000
Total	97,560,000	164,278,000
Fair Value, Available for sale:
Within one year	201,000
One to five years	8,805,000
Five to ten years	86,419,000
Estimated Fair Value	95,425,000	152,757,000
Amortized Cost, Held to maturity:
One to five years	7,455,000
Five to ten years	3,828,000
Total	11,283,000	11,254,000
Fair Value, Held to maturity:
One to five years	7,414,000
Five to ten years	3,963,000
Estimated Fair Value	11,377,000	10,879,000
State and municipal obligations
Amortized Cost, Available for sale:
Within one year	15,574,000
One to five years	27,707,000
Five to ten years	9,470,000
Beyond ten years	10,832,000
Total	63,583,000	62,141,000
Fair Value, Available for sale:
Within one year	15,654,000
One to five years	27,712,000
Five to ten years	9,518,000
Beyond ten years	10,809,000
Estimated Fair Value	63,693,000	61,656,000
Amortized Cost, Held to maturity:
Within one year	5,139,000
One to five years	11,507,000
Five to ten years	42,101,000
Beyond ten years	6,117,000
Total	64,864,000	67,232,000
Fair Value, Held to maturity:
Within one year	5,149,000
One to five years	11,596,000
Five to ten years	43,309,000
Beyond ten years	6,370,000
Estimated Fair Value	66,424,000	67,916,000
U.S. GSE residential mortgage-backed securities
Amortized Cost, Available for sale:
Five to ten years	4,566,000
Beyond ten years	96,365,000
Total	100,931,000	14,609,000
Fair Value, Available for sale:
Five to ten years	4,594,000
Beyond ten years	96,831,000
Estimated Fair Value	101,425,000	14,435,000
Amortized Cost, Held to maturity:
Beyond ten years	6,667,000
Total	6,667,000	8,001,000
Fair Value, Held to maturity:
Beyond ten years	6,570,000
Estimated Fair Value	6,570,000	7,689,000
U.S. GSE Residential collateralized mortgage Obligations
Amortized Cost, Available for sale:
Beyond ten years	261,256,000
Total	261,256,000	285,595,000
Fair Value, Available for sale:
Beyond ten years	258,599,000
Estimated Fair Value	258,599,000	279,191,000
Amortized Cost, Held to maturity:
Five to ten years	1,009,000
Beyond ten years	58,530,000
Total	59,539,000	68,197,000
Fair Value, Held to maturity:
Five to ten years	1,041,000
Beyond ten years	58,143,000
Estimated Fair Value	59,184,000	65,079,000
U.S. GSE commercial mortgage-backed securities
Amortized Cost, Available for sale:
Five to ten years	3,016,000
Total	3,016,000	3,076,000
Fair Value, Available for sale:
Five to ten years	2,945,000
Estimated Fair Value	2,945,000	2,834,000
Amortized Cost, Held to maturity:
Five to ten years	9,935,000
Beyond ten years	3,278,000
Total	13,213,000	10,132,000
Fair Value, Held to maturity:
Five to ten years	10,073,000
Beyond ten years	3,347,000
Estimated Fair Value	13,420,000	9,776,000
U.S. GSE commercial collateralized mortgage obligations
Amortized Cost, Available for sale:
Beyond ten years	24,179,000
Total	24,179,000	26,740,000
Fair Value, Available for sale:
Beyond ten years	24,082,000
Estimated Fair Value	24,082,000	26,910,000
Amortized Cost, Held to maturity:
Beyond ten years	36,413,000
Total	36,413,000	13,627,000
Fair Value, Held to maturity:
Beyond ten years	36,249,000
Estimated Fair Value	36,249,000	12,921,000
Non Agency commercial mortgage-backed securities
Amortized Cost, Available for sale:
Total		3,658,000
Fair Value, Available for sale:
Estimated Fair Value		3,578,000
Other Asset backed securities
Amortized Cost, Available for sale:
Beyond ten years	24,190,000
Total	24,190,000	34,970,000
Fair Value, Available for sale:
Beyond ten years	23,037,000
Estimated Fair Value	23,037,000	33,818,000
Corporate bonds
Amortized Cost, Available for sale:
One to five years	1,000,000
Five to ten years	16,952,000
Total	17,952,000
Fair Value, Available for sale:
One to five years	1,001,000
Five to ten years	16,977,000
Estimated Fair Value	17,978,000
Amortized Cost, Held to maturity:
Within one year	11,948,000
One to five years	11,000,000
Total	22,948,000	22,885,000
Fair Value, Held to maturity:
Within one year	11,990,000
One to five years	11,075,000
Estimated Fair Value	$ 23,065,000	$ 23,079,000