DEPOSITS DEPOSITS (Maturities and Weighted Average Interest Rates of Certificates of Deposit) (Details) - USD ($) $ in Thousands		Sep. 30, 2017	Dec. 31, 2016
Maturities of Time Deposits [Abstract]
Maturing in one year or less		$ 808,770
Maturing after one year through two years		107,060
Maturing after two years through three years		137,253
Maturing after three years through four years		27,870
Maturing after four years through five years		17,208
Maturing after five years		2,413
Total certificates of deposit	[1]	$ 1,100,574	$ 1,045,333
Weighted Average Rate [Abstract]
Maturing in one year or less		0.51%
Maturing after one year through two years		0.69%
Maturing after two years through three years		1.26%
Maturing after three years through four years		1.08%
Maturing after four years through five years		1.21%
Maturing after five years		1.05%
Total certificates of deposit		0.65%

[1] Certificates of deposit include $30,000 and $426,000 of acquisition premiums at September 30, 2017 and December 31, 2016, respectively.