ALLOWANCE FOR CREDIT LOSSES (Allowance For Credit Losses By Segment, Class And Impairment Status) (Details) - USD ($)	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	$ 49,646,000	$ 51,392,000
Allowance for impaired loans and leases	2,270,000	2,350,000
Allowance for all other loans and leases	124,236,000	124,108,000
Total allowance	126,506,000	126,458,000	$ 136,660,000	$ 142,443,000
Evaluated for impairment threshold	500,000
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	17,286,000	17,781,000
Allowance for impaired loans and leases	696,000	1,110,000
Allowance for all other loans and leases	24,717,000	24,398,000
Total allowance	$ 25,413,000	25,508,000	21,502,000	23,562,000
All Other [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans		$ 103,000
Allowance for impaired loans and leases
Allowance for all other loans and leases	$ 6,380,000	$ 6,117,000
Total allowance	6,380,000	6,117,000	11,478,000	11,761,000
Commercial And Industrial [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	8,201,000	7,127,000
Allowance for impaired loans and leases	570,000	78,000
Allowance for all other loans and leases	18,710,000	17,505,000
Total allowance	19,280,000	17,583,000	21,021,000	21,419,000
Consumer Mortgages [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	3,733,000	3,990,000
Allowance for all other loans and leases	33,346,000	33,198,000
Total allowance	33,346,000	33,198,000	39,071,000	40,015,000
Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	$ 1,790,000	1,795,000
Allowance for impaired loans and leases
Allowance for all other loans and leases	$ 7,033,000	6,949,000
Total allowance	7,033,000	6,949,000	9,546,000	9,542,000
Agricultural [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	855,000	872,000
Allowance for impaired loans and leases	191,000	159,000
Allowance for all other loans and leases	2,210,000	2,365,000
Total allowance	2,401,000	2,524,000	3,146,000	3,420,000
Commercial And Industrial - Owner Occupied [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	11,860,000	12,141,000
Allowance for impaired loans and leases	809,000	326,000
Allowance for all other loans and leases	13,940,000	14,281,000
Total allowance	14,749,000	14,607,000	15,664,000	16,325,000
Construction, Acquisition And Development [Member]
Financing Receivable, Impaired [Line Items]
Recorded balance of impaired loans	5,921,000	7,583,000
Allowance for impaired loans and leases	4,000	677,000
Allowance for all other loans and leases	14,660,000	15,248,000
Total allowance	14,664,000	15,925,000	9,913,000	9,885,000
Credit Cards [Member]
Financing Receivable, Impaired [Line Items]
Allowance for all other loans and leases	3,240,000	4,047,000
Total allowance	$ 3,240,000	$ 4,047,000	$ 5,319,000	$ 6,514,000