ALLOWANCE FOR CREDIT LOSSES (Changes In The Allowance For Credit Losses By Segment And Class) (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	$ 123,736	$ 126,458	$ 126,458
Charge-offs		(3,243)	(17,019)
Recoveries		2,291	10,297
Provision	1,000	1,000	4,000
Balance at end of period		126,506	123,736
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	19,170	17,583	17,583
Charge-offs	(384)	(140)	(4,551)
Recoveries	490	212	1,833
Provision	1,291	1,625	4,305
Balance at end of period	20,567	19,280	19,170
Real Estate [Member] | Consumer Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	30,386	33,198	33,198
Charge-offs	(596)	(710)	(2,687)
Recoveries	625	455	1,694
Provision	1,340	403	(1,819)
Balance at end of period	31,755	33,346	30,386
Real Estate [Member] | Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	7,174	6,949	6,949
Charge-offs	(459)	(550)	(1,884)
Recoveries	356	80	506
Provision	(39)	554	1,603
Balance at end of period	7,032	7,033	7,174
Real Estate [Member] | Agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	2,172	2,524	2,524
Charge-offs	(44)	(11)	(110)
Recoveries	41	36	175
Provision	109	(148)	(417)
Balance at end of period	2,278	2,401	2,172
Real Estate [Member] | Commercial And Industrial - Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	12,899	14,607	14,607
Charge-offs	(404)	(154)	(1,095)
Recoveries	193	125	544
Provision	1,178	171	(1,157)
Balance at end of period	13,866	14,749	12,899
Real Estate [Member] | Construction, Acquisition And Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	13,957	15,925	15,925
Charge-offs	(30)	(226)	(521)
Recoveries	1,324	272	1,373
Provision	(1,766)	(1,307)	(2,820)
Balance at end of period	13,485	14,664	13,957
Real Estate [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	24,845	25,508	25,508
Charge-offs	(19)	(245)	(1,129)
Recoveries	69	683	2,411
Provision	767	(533)	(1,945)
Balance at end of period	25,662	25,413	24,845
Credit Cards [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	7,787	4,047	4,047
Charge-offs	(838)	(720)	(2,845)
Recoveries	249	181	850
Provision	(1,032)	(268)	5,735
Balance at end of period	6,166	3,240	7,787
All Other [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at beginning of period	5,346	6,117	6,117
Charge-offs	(559)	(487)	(2,197)
Recoveries	446	247	911
Provision	(848)	503	515
Balance at end of period	$ 4,385	$ 6,380	$ 5,346