REGULATORY MATTERS AND CAPITAL (Schedule of Bank Capital and Ratio) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 capital to risk weighted assets, actual amount	$ 699,728	$ 691,195
Common Equity Tier 1 capital to risk weighted assets, actual ratio	9.72%	10.55%
Common Equity Tier 1 capital to risk weighted assets, required for capital adequacy purposes, amount	$ 324,035	$ 294,823
Common Equity Tier 1 capital to risk weighted assets, required for capital adequacy purposes, ratio	4.50%	4.50%
Tier 1 capital to risk weighted assets, actual amount	$ 790,228	$ 781,695
Tier 1 capital to risk weighted assets, actual ratio	10.97%	11.93%
Tier 1 capital to risk weighted assets, required for capital adequacy purposes, amount	$ 432,047	$ 393,141
Tier 1 capital ratio of risk-weighted assets	6.00%	6.00%
Total capital to risk weighted assets, actual amount	$ 976,145	$ 816,041
Total capital to risk weighted assets, actual ratio	13.56%	12.46%
Total capital to risk weighted assets, Required for Capital adequacy purposes, amount	$ 576,062	$ 523,943
Total capital to risk weighted assets, required for capital adequacy purposes, ratio	8.00%	8.00%
Tier 1 capital to average adjusted assets, actual amount	$ 790,228	$ 781,695
Tier 1 capital to average adjusted assets, actual ratio	9.87%	10.68%
Tier 1 capital to average adjusted assets, required for capital adequacy purposes, amount	$ 320,316	$ 292,770
Tier 1 capital to average adjusted assets, required for capital adequacy purposes, ratio	4.00%	4.00%
Union Bank & Trust
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common Equity Tier 1 capital to risk weighted assets, actual amount	$ 901,783	$ 751,992
Common Equity Tier 1 capital to risk weighted assets, actual ratio	12.58%	11.52%
Common Equity Tier 1 capital to risk weighted assets, required for capital adequacy purposes, amount	$ 322,531	$ 293,747
Common Equity Tier 1 capital to risk weighted assets, required for capital adequacy purposes, ratio	4.50%	4.50%
Common Equity Tier 1 capital to risk weighted assets, required in order to be well capitalized under PCA, amount	$ 465,878	$ 424,301
Common Equity Tier 1 capital to risk weighted assets, required in order to be well capitalized under PCA, ratio	6.50%	6.50%
Tier 1 capital to risk weighted assets, actual amount	$ 901,783	$ 751,992
Tier 1 capital to risk weighted assets, actual ratio	12.58%	11.52%
Tier 1 capital to risk weighted assets, required for capital adequacy purposes, amount	$ 430,042	$ 391,663
Tier 1 capital ratio of risk-weighted assets	6.00%	6.00%
Tier 1 capital to risk weighted assets, required in order to be well capitalized under PCA, amount	$ 573,389	$ 522,217
Tier 1 capital to risk weighted assets, required in order to be well capitalized under PCA, ratio	8.00%	8.00%
Total capital to risk weighted assets, actual amount	$ 939,700	$ 786,339
Total capital to risk weighted assets, actual ratio	13.11%	12.05%
Total capital to risk weighted assets, Required for Capital adequacy purposes, amount	$ 573,390	$ 522,051
Total capital to risk weighted assets, required for capital adequacy purposes, ratio	8.00%	8.00%
Total capital to risk weighted assets, required in order to be well capitalized under PCA, amount	$ 716,737	$ 652,563
Total capital to risk weighted assets, required in order to be well capitalized under PCA, ratio	10.00%	10.00%
Tier 1 capital to average adjusted assets, actual amount	$ 901,783	$ 751,992
Tier 1 capital to average adjusted assets, actual ratio	11.31%	10.31%
Tier 1 capital to average adjusted assets, required for capital adequacy purposes, amount	$ 319,046	$ 291,752
Tier 1 capital to average adjusted assets, required for capital adequacy purposes, ratio	4.00%	4.00%
Tier 1 capital to average adjusted assets, required in order to be well capitalized under PCA, amount	$ 398,807	$ 364,691
Tier 1 capital to average adjusted assets, required in order to be well capitalized under PCA, ratio	5.00%	5.00%