FAIR VALUE DISCLOSURES (Details) (Recurring, USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	$ 2,126,271	$ 2,505,400
Liabilities, fair value disclosure, recurring	6,530	7,645
U.S. Government sponsored agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	310,429	341,817
Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	1,534,067	1,924,920
Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	915	910
State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	4,929	5,410
Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	192,365	183,813
Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	1,022	1,017
Mortgage loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	66,133	31,111
Customer interest rate swap agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	87	370
Liabilities, fair value disclosure, recurring	87	307
Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	1,837	1,381
Forward commitments to sell mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	(305)	(729)
Servicing rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	14,792	15,380
Interest rate swap agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, fair value disclosure, recurring	0	807
Nonqualified deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, fair value disclosure, recurring	6,443	6,531
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	1,022	1,017
Liabilities, fair value disclosure, recurring	6,443	6,531
Fair Value, Inputs, Level 1 | U.S. Government sponsored agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	1,022	1,017
Fair Value, Inputs, Level 1 | Mortgage loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | Customer interest rate swap agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Liabilities, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | Forward commitments to sell mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | Servicing rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | Interest rate swap agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 1 | Nonqualified deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, fair value disclosure, recurring	6,443	6,531
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	2,110,457	2,489,003
Liabilities, fair value disclosure, recurring	87	1,114
Fair Value, Inputs, Level 2 | U.S. Government sponsored agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	310,429	341,817
Fair Value, Inputs, Level 2 | Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	1,534,067	1,924,920
Fair Value, Inputs, Level 2 | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	915	910
Fair Value, Inputs, Level 2 | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	4,929	5,410
Fair Value, Inputs, Level 2 | Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	192,365	183,813
Fair Value, Inputs, Level 2 | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 2 | Mortgage loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	66,133	31,111
Fair Value, Inputs, Level 2 | Customer interest rate swap agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	87	370
Liabilities, fair value disclosure, recurring	87	307
Fair Value, Inputs, Level 2 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	1,837	1,381
Fair Value, Inputs, Level 2 | Forward commitments to sell mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	(305)	(729)
Fair Value, Inputs, Level 2 | Servicing rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 2 | Interest rate swap agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, fair value disclosure, recurring	0	807
Fair Value, Inputs, Level 2 | Nonqualified deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	14,792	15,380
Liabilities, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | U.S. Government sponsored agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | Residential mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | Corporate notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | Mortgage loans held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | Customer interest rate swap agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Liabilities, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | Interest rate lock commitments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | Forward commitments to sell mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | Servicing rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure, recurring	14,792	15,380
Fair Value, Inputs, Level 3 | Interest rate swap agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, fair value disclosure, recurring	0	0
Fair Value, Inputs, Level 3 | Nonqualified deferred compensation plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, fair value disclosure, recurring	$ 0	$ 0