Regulatory Matters - Risk-Based Capital Ratios (Detail) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital (to risk-weighted assets), Actual, Amount	$ 90,000,000
Tier 1 capital (to risk-weighted assets), Actual, Amount	62,700,000
Sun Bancorp, Inc. [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital (to risk-weighted assets), Actual, Amount	$ 357,177	$ 354,078
Total risk-based capital (to risk-weighted assets), Actual, Ratio	21.88%	21.63%
Total risk-based capital (to risk-weighted assets), For Capital Adequacy Purposes, Amount	$ 130,618,000	$ 130,929,000
Total risk-based capital (to risk-weighted assets), For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Total risk-based capital (to risk-weighted assets), Minimum Capital Requirement with Conservation Buffer, Amount	$ 151,027,000	$ 141,157,000
Total risk-based capital (to risk-weighted assets), Minimum Capital Requirement with Conservation Buffer, Ratio	9.25%	8.625%
Tier 1 common equity capital ratio (to risk-weighed assets), Actual, Amount	$ 257,846	$ 262,386
Tier 1 common equity capital ratio (to risk-weighed assets), Actual, Ratio	15.79%	16.03%
Tier 1 common equity capital ratio (to risk-weighed assets), For Capital Adequacy Purposes, Amount	$ 73,473,000	$ 73,647,000
Tier 1 common equity capital ratio (to risk-weighed assets), For Capital Adequacy Purposes, Ratio	4.50%	4.50%
Tier 1 common equity capital ratio (to risk-weighed assets), Minimum Capital Requirement with Conservation Buffer, Amount	$ 93,882,000	$ 83,876,000
Tier 1 common equity capital ratio (to risk-weighed assets), Minimum Capital Requirement with Conservation Buffer, Ratio	5.75%	5.125%
Tier 1 capital (to risk-weighted assets), Actual, Amount	$ 313,271	$ 309,910
Tier 1 capital (to risk-weighted assets), Actual, Ratio	19.19%	18.94%
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Purposes, Amount	$ 97,964,000	$ 98,196,000
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Purposes, Ratio	6.00%	6.00%
Tier 1 capital (to risk-weighted assets), Minimum Capital Requirement with Conservation Buffer, Amount	$ 118,373,000	$ 108,425,000
Tier 1 capital (to risk-weighted assets), Minimum Capital Requirement with Conservation Buffer, Ratio	7.25%	6.625%
Leverage capital, Actual, Amount	$ 313,271	$ 309,910
Leverage capital, Actual, Ratio	14.46%	14.57%
Leverage capital, For Capital Adequacy Purposes, Amount	$ 86,657,000	$ 85,092,000
Leverage capital, For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Sun National Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total risk-based capital (to risk-weighted assets), Actual, Amount	$ 307,118	$ 324,196
Total risk-based capital (to risk-weighted assets), Actual, Ratio	18.82%	19.85%
Total risk-based capital (to risk-weighted assets), For Capital Adequacy Purposes, Amount	$ 130,548,000	$ 130,664,000
Total risk-based capital (to risk-weighted assets), For Capital Adequacy Purposes, Ratio	8.00%	8.00%
Total risk-based capital (to risk-weighted assets), Minimum Capital Requirement with Conservation Buffer, Amount	$ 150,946,000	$ 140,872,000
Total risk-based capital (to risk-weighted assets), Minimum Capital Requirement with Conservation Buffer, Ratio	9.25%	8.625%
Total risk-based capital (to risk-weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 163,186,000	$ 163,330,000
Total risk-based capital (to risk-weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%	10.00%
Tier 1 common equity capital ratio (to risk-weighed assets), Actual, Amount	$ 290,555	$ 308,043
Tier 1 common equity capital ratio (to risk-weighed assets), Actual, Ratio	17.81%	18.86%
Tier 1 common equity capital ratio (to risk-weighed assets), For Capital Adequacy Purposes, Amount	$ 73,434,000	$ 73,498,000
Tier 1 common equity capital ratio (to risk-weighed assets), For Capital Adequacy Purposes, Ratio	4.50%	4.50%
Tier 1 common equity capital ratio (to risk-weighed assets), Minimum Capital Requirement with Conservation Buffer, Amount	$ 93,832,000	$ 83,707,000
Tier 1 common equity capital ratio (to risk-weighed assets), Minimum Capital Requirement with Conservation Buffer, Ratio	5.75%	5.125%
Tier 1 common equity capital ratio (to risk-weighed assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 106,071,000	$ 106,164,000
Tier 1 common equity capital ratio (to risk-weighed assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.50%	6.50%
Tier 1 capital (to risk-weighted assets), Actual, Amount	$ 290,555	$ 308,043
Tier 1 capital (to risk-weighted assets), Actual, Ratio	17.81%	18.86%
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Purposes, Amount	$ 97,911,000	$ 97,998,000
Tier 1 capital (to risk-weighted assets), For Capital Adequacy Purposes, Ratio	6.00%	6.00%
Tier 1 capital (to risk-weighted assets), Minimum Capital Requirement with Conservation Buffer, Amount	$ 118,309,000	$ 108,206,000
Tier 1 capital (to risk-weighted assets), Minimum Capital Requirement with Conservation Buffer, Ratio	7.25%	6.625%
Tier 1 capital (to risk-weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 130,548,000	$ 130,664,000
Tier 1 capital (to risk-weighted assets), To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	8.00%	8.00%
Leverage capital, Actual, Amount	$ 290,555	$ 308,043
Leverage capital, Actual, Ratio	13.43%	14.50%
Leverage capital, For Capital Adequacy Purposes, Amount	$ 86,518,000	$ 84,959,000
Leverage capital, For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Leverage capital, To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 108,147,000	$ 106,199,000
Leverage capital, To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%	5.00%