LOANS AND LEASES - Nonaccrual, Restructured and Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Financing Receivable, Modifications [Line Items]
Nonaccrual loans	$ 22,007		$ 27,997
Accruing trouble debt restructurings	30,127		28,876
Total impaired loans	52,134		56,873
Restructured loans - nonaccrual status	7,500		9,300
Interest income effect
Gross amount of interest that would have been recorded under original terms	754	$ 967
Interest included in income
Nonaccrual loans	76	171
Troubled debt restructurings	232	132
Total interest included in income	308	303	1,157
Net impact on interest income	446	$ 664
Commercial
Financing Receivable, Modifications [Line Items]
Nonaccrual loans	3,917		8,405
Total impaired loans	14,485		17,411
Interest included in income
Total interest included in income	83		284
Real estate - construction
Financing Receivable, Modifications [Line Items]
Nonaccrual loans	0		0
Total impaired loans	0		0
Interest included in income
Total interest included in income	0		0
Real estate - commercial
Financing Receivable, Modifications [Line Items]
Nonaccrual loans	8,577		9,418
Total impaired loans	22,977		24,652
Interest included in income
Total interest included in income	147		557
Real estate - residential
Financing Receivable, Modifications [Line Items]
Nonaccrual loans	4,243		5,027
Total impaired loans	8,663		8,994
Interest included in income
Total interest included in income	55		224
Installment
Financing Receivable, Modifications [Line Items]
Nonaccrual loans	113		127
Total impaired loans	219		253
Interest included in income
Total interest included in income	1		7
Home equity
Financing Receivable, Modifications [Line Items]
Nonaccrual loans	5,036		4,898
Total impaired loans	5,669		5,441
Interest included in income
Total interest included in income	22		85
Other
Financing Receivable, Modifications [Line Items]
Nonaccrual loans	121		122
Total impaired loans	121		122
Interest included in income
Total interest included in income	$ 0		$ 0