Regulatory Capital - (Capital Ratio Requirements under Prompt Corrective Action or Other Regulatory Requirements) (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Parent Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Leverage Ratio	10.30%	10.40%
Common equity risk-based ratio	13.30%	14.20%
Risk-based capital Ratio	13.30%	14.20%
Total risk-based capital Ratio	14.30%	15.00%
Leverage Amount	$ 472,627	$ 470,259
Common equity risk-based amount	472,627	470,259
Risk-based capital amount	472,627	470,259
Total risk-based capital Amount	$ 507,912	$ 499,759
Required to be considered adequately capitalized Ratio, leverage ratio	4.00%	4.00%
Required to be considered adequately capitalized Ratio, risk-based common equity capital ratio	4.50%	4.50%
Required to be considered adequately capitalized Ratio, risk-based capital ratio	6.00%	6.00%
Required to be considered adequately capitalized Ratio, Total risk-based capital ratio	8.00%	8.00%
Required to be considered adequately capitalized leverage Amount	$ 184,402	$ 181,019
Required to be considered adequately capitalized common equity capital amount	207,452	203,647
Required to be considered adequately capitalized risk-based capital Amount	213,366	199,467
Required to be considered adequately capitalized Total risk-based capital Amount	$ 284,488	$ 265,955
NBH Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Leverage Ratio	8.40%	8.60%
Common equity risk-based ratio	10.90%	11.80%
Risk-based capital Ratio	10.90%	11.80%
Total risk-based capital Ratio	11.90%	12.70%
Leverage Amount	$ 385,466	$ 389,189
Common equity risk-based amount	385,466	389,189
Risk-based capital amount	385,466	389,189
Total risk-based capital Amount	$ 420,750	$ 418,689
Required to be considered well capitalized Ratio, leverage ratio	4.50%	4.50%
Required to be considered adequately capitalized Ratio, risk-based common equity capital ratio	6.50%	6.50%
Required to be considered well capitalized Ratio, risk-based capital ratio	8.00%	8.00%
Required to be considered well capitalized Ratio, Total risk-based capital ratio	10.00%	10.00%
Required to be considered well capitalized leverage Amount	$ 206,721	$ 202,903
Required to be considered well capitalized common equity capital amount	298,597	293,082
Required to be considered well capitalized risk-based capital Amount	283,313	264,596
Required to be considered well capitalized Total risk-based capital Amount	$ 354,141	$ 330,745
Required to be considered adequately capitalized Ratio, leverage ratio	4.00%	4.00%
Required to be considered adequately capitalized Ratio, risk-based common equity capital ratio	4.50%	4.50%
Required to be considered adequately capitalized Ratio, risk-based capital ratio	6.00%	6.00%
Required to be considered adequately capitalized Ratio, Total risk-based capital ratio	8.00%	8.00%
Required to be considered adequately capitalized leverage Amount	$ 183,752	$ 180,358
Required to be considered adequately capitalized common equity capital amount	206,721	202,903
Required to be considered adequately capitalized risk-based capital Amount	212,485	198,447
Required to be considered adequately capitalized Total risk-based capital Amount	$ 283,313	$ 264,596