BORROWED FUNDS - Short-term Borrowings and Repurchase Agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Borrowed funds
Remaining maximum borrowing capacity with the FHLB	$ 326,900
FHLB and other borrowings	90,921	$ 183,198
Short-term Borrowings from FHLB
Short-term Borrowings and Repurchase Agreements
Balance at end of year	87,733	179,917	$ 95,829
Average balance during the year	137,822	121,425	76,185
Maximum month-end balance	$ 210,600	$ 179,917	$ 120,229
Weighted-average rate during the year	0.51%	0.34%	0.27%
Weighted-average rate at December 31	0.74%	0.44%	0.32%
Repurchase Agreements
Short-term Borrowings and Repurchase Agreements
Balance at end of year	$ 25,160	$ 27,437	$ 32,673
Average balance during the year	27,066	26,884	55,731
Maximum month-end balance	$ 29,561	$ 32,470	$ 83,781
Weighted-average rate during the year	0.27%	0.31%	0.52%
Weighted-average rate at December 31	0.28%	0.30%	0.35%
Investment Securities
Short-term Borrowings and Repurchase Agreements
Investment securities held as collateral	$ 26,000	$ 28,300
Subordinated Debt
Short-term Borrowings and Repurchase Agreements
Weighted-average rate during the year	6.64%	6.57%	6.01%