SEGMENT INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Information about reportable segments
Net interest income	$ 60,601	$ 58,775	$ 177,458	$ 170,455
Provision for loan losses	2,093	2,643	4,807	6,442
Noninterest income	27,594	25,859	80,801	73,023
Amortization of intangible assets	1,089	1,212	3,408	3,343
Other operating expenses	53,955	54,873	160,564	151,515
Income before income taxes	31,058	25,906	89,480	82,178
Assets	7,302,017	7,570,373	7,302,017	7,570,373	7,496,800
Goodwill	369,703	369,703	369,703	369,703	369,703
Eliminations [Member]
Information about reportable segments
Net interest income	0	0	0	0
Provision for loan losses	0	0	0	0
Noninterest income	(527)	(541)	(1,717)	(1,630)
Amortization of intangible assets	0	0	0	0
Other operating expenses	(527)	(541)	(1,717)	(1,630)
Income before income taxes	0	0	0	0
Assets	(14,519)	(17,083)	(14,519)	(17,083)
Goodwill	0	0	0	0
Banking [Member]
Information about reportable segments
Net interest income	60,566	58,730	177,319	170,329
Provision for loan losses	2,093	2,643	4,807	6,442
Noninterest income	14,372	13,753	40,667	37,045
Amortization of intangible assets	875	958	2,720	2,536
Other operating expenses	43,497	44,796	129,674	121,902
Income before income taxes	28,473	24,086	80,785	76,494
Assets	7,276,673	7,546,153	7,276,673	7,546,153
Goodwill	359,207	359,207	359,207	359,207
Other [Member]
Information about reportable segments
Net interest income	35	45	139	126
Provision for loan losses	0	0	0	0
Noninterest income	13,749	12,647	41,851	37,608
Amortization of intangible assets	214	254	688	807
Other operating expenses	10,985	10,618	32,607	31,243
Income before income taxes	2,585	1,820	8,695	5,684
Assets	39,863	41,303	39,863	41,303
Goodwill	$ 10,496	$ 10,496	$ 10,496	$ 10,496