GOODWILL AND OTHER INTANGIBLE ASSETS (Details) (USD $)	3 Months Ended			9 Months Ended		3 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Mar. 31, 2012 EQF	Jun. 30, 2012 Celtic	Sep. 30, 2012 APB
Changes in the carrying amount of goodwill
Balance, at the beginning of the period				$ 39,141,000
Tax deductible addition from acquisition						19,033,000
Non-tax deductible addition from acquisition							5,855,000	15,563,000
Balance, at the end of the period	79,592,000			79,592,000
Gross amount of CDI and CRI:
Balance, beginning of period	62,272,000	60,972,000	73,629,000	67,100,000	76,319,000
Addition	1,924,000	1,300,000		4,924,000
Fully amortized portion	(12,918,000)		(6,529,000)	(20,746,000)	(9,219,000)
Removal due to branch sale	(5,866,000)			(5,866,000)
Balance, end of period	45,412,000	62,272,000	67,100,000	45,412,000	67,100,000
Accumulated Amortization:
Balance, end of period	(45,329,000)	(43,592,000)	(52,401,000)	(49,685,000)	(50,476,000)
Amortization	(1,678,000)	(1,737,000)	(1,977,000)	(5,150,000)	(6,592,000)
Fully amortized portion	12,918,000		6,529,000	20,746,000	9,219,000
Removal due to branch sale	4,576,000			4,576,000
Balance, beginning of period	(29,513,000)	(45,329,000)	(47,849,000)	(29,513,000)	(47,849,000)
Finite lived intangible assets, net
Net CDI and CRI, end of period	15,899,000	16,943,000	19,251,000	15,899,000	19,251,000
Additional information
Amount of CDI written off related to previously acquired deposits that were sold in connection with the sale of branches	1,300,000
Estimated aggregate amortization expense related to the intangible assets
2012	6,300,000			6,300,000
2013	4,500,000			4,500,000
2014	3,800,000			3,800,000
2015	3,500,000			3,500,000
2016	$ 1,800,000			$ 1,800,000