INVESTMENT SECURITIES (Details 5) (USD $)														9 Months Ended
	Sep. 30, 2013 item	Dec. 31, 2012 item	Sep. 30, 2013 US Government Agencies and Government Sponsored Enterprise Debt Securities item	Dec. 31, 2012 US Government Agencies and Government Sponsored Enterprise Debt Securities item	Sep. 30, 2013 Other residential mortgage-backed securities item	Sep. 30, 2013 Other residential mortgage-backed securities Investment grade	Sep. 30, 2013 Corporate debt securities Investment grade item	Dec. 31, 2012 Corporate debt securities Investment grade item	Sep. 30, 2013 Corporate debt securities Non-investment grade		Dec. 31, 2012 Corporate debt securities Non-investment grade		Sep. 30, 2012 Corporate debt securities Non-investment grade	Sep. 30, 2012 Trust Preferred Securities	Sep. 30, 2013 Trust Preferred Securities Non-investment grade item	Dec. 31, 2012 Trust Preferred Securities Non-investment grade item	Sep. 30, 2013 Municipal securities item	Dec. 31, 2012 Municipal securities item	Sep. 30, 2013 Other securities item	Dec. 31, 2012 Other securities	Sep. 30, 2013 U.S. Treasury securities item	Dec. 31, 2012 U.S. Treasury securities item	Sep. 30, 2013 Other commercial mortgage-backed securities: Investment grade	Dec. 31, 2012 Other commercial mortgage-backed securities: Investment grade	Sep. 30, 2013 U.S. Government agency and U.S. Government sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities item	Dec. 31, 2012 U.S. Government agency and U.S. Government sponsored enterprise mortgage-backed securities - Commercial mortgage-backed securities item	Sep. 30, 2013 U.S. Government agency and U.S. Government sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities item	Dec. 31, 2012 U.S. Government agency and U.S. Government sponsored enterprise mortgage-backed securities - Residential mortgage-backed securities item	Sep. 30, 2013 U.S. Government agency and U.S. Government sponsored enterprise debt securities	Dec. 31, 2012 U.S. Government agency and U.S. Government sponsored enterprise debt securities
Schedule of Available-for-sale Securities
Fair value of available for sale securities	$ 2,892,761,000	$ 2,607,029,000				$ 14,692,000	$ 465,928,000	$ 411,983,000	$ 14,942,000	[1]	$ 17,417,000	[1]					$ 250,006,000	$ 167,093,000	$ 9,924,000	$ 10,170,000	$ 525,707,000	$ 460,677,000	$ 51,293,000	$ 17,084,000	$ 179,258,000	$ 180,665,000	$ 977,950,000	$ 1,144,085,000	$ 403,061,000	$ 197,855,000
Continuous unrealized loss position 12 months or more, fair value	125,997,000	195,271,000					86,201,000	182,697,000	14,285,000		12,574,000				14,300,000	12,600,000											25,511,000
Total investment securities available-for-sale portfolio (as a percent)															1.00%		9.00%	6.00%									34.00%	44.00%	14.00%
Number of securities in a continuous unrealized loss position for more than twelve months	13	13					4	8							5	5											4
Number of individual securities with a continuous unrealized loss position less than 12 months	258	77	11	1	2		15	11									105	29	3		30	9			21	1	71	26
Percentage of total amortized cost basis of these securities									29.00%
Gross unrealized losses in loss position twelve months or more	(10,254,000)	(19,739,000)					(3,798,000)	(12,181,000)	(5,773,000)		(7,558,000)																(683,000)
Gross unrealized losses, trust preferred securities, portion representing impairment loss on securities not other-than-temporarily-impaired													3,900,000
Gross unrealized losses, trust preferred securities, portion representing non-credit impairment loss on securities other-than-temporarily-impaired													5,100,000
Impairment loss relating to additional increases to the amount related to the credit loss for which an other-than-temporary impairment was previously recognized														$ 99,000

[1] For the nine months ended September 30, 2013, the Company did not record any OTTI. The Company recorded $99 thousand, on a pre-tax basis, of the credit portion of OTTI through earnings and $5.1 million of the non-credit portion of OTTI for pooled trust preferred securities in other comprehensive income for the year ended December 31, 2012.