FAIR VALUE DISCLOSURES (Schedule of Items Measured on a Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	$ 1,329,957		$ 1,445,689
Servicing rights	18,048	$ 19,041	18,013	$ 19,106	$ 18,784	$ 18,854
U.S. Government sponsored agencies [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	226,102		231,731
Residential mortgage-backed [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	879,010		1,007,844
Commercial mortgage-backed [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	20,273		837
State and political subdivisions [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	28,000		29,615
Corporate notes [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	174,596		173,695
Equity investments [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	1,976		1,967
Fair Value, Measurements, Recurring [Member]
Assets, Fair Value Disclosure [Abstract]
Mortgage loans held for sale	39,041		31,411
Servicing rights	18,048		18,013
Total assets, fair value disclosure (recurring)	1,387,574		1,495,399
Fair Value, Measurements, Recurring [Member] | Interest rate lock commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Assets	990		580
Fair Value, Measurements, Recurring [Member] | Forward commitments to sell mortgage-backed securities [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Assets	(462)		(294)
Fair Value, Measurements, Recurring [Member] | U.S. Government sponsored agencies [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	226,102		231,731
Fair Value, Measurements, Recurring [Member] | Residential mortgage-backed [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	879,010		1,007,844
Fair Value, Measurements, Recurring [Member] | Commercial mortgage-backed [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	20,273		837
Fair Value, Measurements, Recurring [Member] | State and political subdivisions [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	28,000		29,615
Fair Value, Measurements, Recurring [Member] | Corporate notes [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	174,596		173,695
Fair Value, Measurements, Recurring [Member] | Equity investments [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	1,976		1,967
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, Fair Value Disclosure [Abstract]
Mortgage loans held for sale	0		0
Servicing rights	0		0
Total assets, fair value disclosure (recurring)	1,976		1,967
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Interest rate lock commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Assets	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Forward commitments to sell mortgage-backed securities [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Assets	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government sponsored agencies [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Residential mortgage-backed [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial mortgage-backed [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | State and political subdivisions [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate notes [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Equity investments [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	1,976		1,967
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Mortgage loans held for sale	39,041		31,411
Servicing rights	18,048		18,013
Total assets, fair value disclosure (recurring)	1,385,598		1,493,432
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest rate lock commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Assets	990		580
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Forward commitments to sell mortgage-backed securities [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Assets	(462)		(294)
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government sponsored agencies [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	226,102		231,731
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential mortgage-backed [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	879,010		1,007,844
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial mortgage-backed [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	20,273		837
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | State and political subdivisions [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	28,000		29,615
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate notes [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	174,596		173,695
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Equity investments [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, Fair Value Disclosure [Abstract]
Mortgage loans held for sale	0		0
Servicing rights	0		0
Total assets, fair value disclosure (recurring)	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest rate lock commitments [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Assets	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Forward commitments to sell mortgage-backed securities [Member]
Assets, Fair Value Disclosure [Abstract]
Derivative Assets	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government sponsored agencies [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential mortgage-backed [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial mortgage-backed [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | State and political subdivisions [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate notes [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Equity investments [Member]
Assets, Fair Value Disclosure [Abstract]
Available for sale securities, fair value	$ 0		$ 0