FAIR VALUE DISCLOSURES (Details) (Fair Value, Measurements, Recurring [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	$ 1,651,471	$ 2,126,271
Liabilities, Fair Value Disclosure, Recurring	6,268	6,530
U.S. Government sponsored agencies [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	276,034	310,429
Residential mortgage-backed [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	1,098,229	1,534,067
Commercial mortgage-backed [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	868	915
State and political subdivisions [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	32,261	4,929
Corporate notes [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	195,439	192,365
Equity investments [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	1,456	1,022
Mortgage loans held for sale [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	28,313	66,133
Customer interest rate swap agreements [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	7	87
Liabilities, Fair Value Disclosure, Recurring	7	87
Interest rate lock commitments [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	743	1,837
Forward commitments to sell mortgage-backed securities [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	(637)	(305)
Servicing rights [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	18,758	14,792
Nonqualified deferred compensation plan [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure, Recurring	6,261	6,443
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	1,456	1,022
Liabilities, Fair Value Disclosure, Recurring	6,261	6,443
Fair Value, Inputs, Level 1 [Member] | U.S. Government sponsored agencies [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 1 [Member] | Residential mortgage-backed [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 1 [Member] | Commercial mortgage-backed [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 1 [Member] | State and political subdivisions [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 1 [Member] | Corporate notes [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 1 [Member] | Equity investments [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	1,456	1,022
Fair Value, Inputs, Level 1 [Member] | Mortgage loans held for sale [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 1 [Member] | Customer interest rate swap agreements [Member]
Fair Value, Assests 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 [Member] | Interest rate lock commitments [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 1 [Member] | Forward commitments to sell mortgage-backed securities [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 1 [Member] | Servicing rights [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 1 [Member] | Nonqualified deferred compensation plan [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure, Recurring	6,261	6,443
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	1,631,257	2,110,457
Liabilities, Fair Value Disclosure, Recurring	7	87
Fair Value, Inputs, Level 2 [Member] | U.S. Government sponsored agencies [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	276,034	310,429
Fair Value, Inputs, Level 2 [Member] | Residential mortgage-backed [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	1,098,229	1,534,067
Fair Value, Inputs, Level 2 [Member] | Commercial mortgage-backed [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	868	915
Fair Value, Inputs, Level 2 [Member] | State and political subdivisions [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	32,261	4,929
Fair Value, Inputs, Level 2 [Member] | Corporate notes [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	195,439	192,365
Fair Value, Inputs, Level 2 [Member] | Equity investments [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 2 [Member] | Mortgage loans held for sale [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	28,313	66,133
Fair Value, Inputs, Level 2 [Member] | Customer interest rate swap agreements [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	7	87
Liabilities, Fair Value Disclosure, Recurring	7	87
Fair Value, Inputs, Level 2 [Member] | Interest rate lock commitments [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	743	1,837
Fair Value, Inputs, Level 2 [Member] | Forward commitments to sell mortgage-backed securities [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	(637)	(305)
Fair Value, Inputs, Level 2 [Member] | Servicing rights [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 2 [Member] | Nonqualified deferred compensation plan [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	18,758	14,792
Liabilities, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | U.S. Government sponsored agencies [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | Residential mortgage-backed [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | Commercial mortgage-backed [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | State and political subdivisions [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | Corporate notes [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | Equity investments [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | Mortgage loans held for sale [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | Customer interest rate swap agreements [Member]
Fair Value, Assests 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 [Member] | Interest rate lock commitments [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | Forward commitments to sell mortgage-backed securities [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fair Value, Inputs, Level 3 [Member] | Servicing rights [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring	18,758	14,792
Fair Value, Inputs, Level 3 [Member] | Nonqualified deferred compensation plan [Member]
Fair Value, Assests and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities, Fair Value Disclosure, Recurring	$ 0	$ 0