401(K) Retirement Plan (Details) - USD ($)	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
401(K) Retirement Plan
Requisite service period for employees to be eligible for the defined contribution plan	3 months
Requisite age for employees to be eligible for the defined contribution plan	18 years
Employee contributions limit as a percentage of wages, maximum	60.00%
Employer match of employee contributions for 6% of eligible compensation (as a percent)	25.00%
Maximum percentage of covered compensation matched 25% by employer	6.00%
Contributions made	$ 270,000	$ 249,000

Represents the age required for employees to be eligible to participate in the defined contribution plan.

No definition available.

Name:	nsys_DefinedContributionPlanEligibilityAgeOfEmployee
Namespace Prefix:	nsys_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the service period required for employees to be eligible for the defined contribution plan.

+ References

No definition available.

+ Details

Name:	nsys_DefinedContributionPlanEligibilityServicePeriod
Namespace Prefix:	nsys_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The rate at which the employer matches the employees' contribution, up to a separately-specified limit, under a defined contribution plan.

+ References

No definition available.

+ Details

Name:	nsys_DefinedContributionPlanEmployerMatchingContributionRate
Namespace Prefix:	nsys_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration