Costs for defined contribution plans for certain international employees.

No definition available.

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- Definition

Non-contributory Defined Benefit Pension Plan, Description of terms and benefits

+ References

No definition available.

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- Definition

Description of the terms and benefits provided by the employer's defined contribution plans. A defined contribution plan provides benefits in return for services rendered, provides an individual account for each participant, and has terms that specify how contributions to the individual's account are to be determined rather than the amount of benefits the individual is to receive. Under a defined contribution pension plan, the benefits a participant will receive depend solely on the amount contributed to the participant's account, the returns earned on investments of those contributions, and forfeitures of other participants' benefits that may be allocated to such participant's account. A description of the plan(s) including employee groups covered, the basis for determining contributions, and the nature and effects of significant matters affecting comparability of information for all periods presented.

+ 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

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Defined Contribution Plan
-URI http://asc.fasb.org/extlink&oid=49180617

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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EMPLOYEE BENEFIT PLANS AND LONG-TERM INCENTIVE PLANS Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Benefit Plan Costs, International Employees	$ 2.6	$ 2.7	$ 2.5
GP Pension Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pension Plan, Description	The NuStar Pension Plan (the Pension Plan) is a qualified non-contributory defined benefit pension plan that provides eligible employees with retirement income as calculated under a cash balance formula. Under the cash balance formula, benefits are based on age, service and interest credits, and employees become fully vested in their benefits upon attaining three years of vesting service. Prior to January 1, 2014, eligible employees were covered under either a cash balance formula or a final average pay formula (FAP). Effective January 1, 2014, the Pension Plan was amended to freeze the FAP benefits as of December 31, 2013, and going forward, all eligible employees are covered under the cash balance formula discussed above.
GP Thrift Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Thrift Plan, Description	The NuStar Thrift Plan (the Thrift Plan) is a qualified defined contribution plan that became effective June 26, 2006. Participation in the Thrift Plan is voluntary and is open to substantially all NuStar GP, LLC employees upon their date of hire. Thrift Plan participants can contribute from 1% up to 30% of their total annual compensation to the Thrift Plan in the form of pre-tax and/or after tax employee contributions. NuStar GP, LLC makes matching contributions in an amount equal to 100% of each participant’s employee contributions up to a maximum of 6% of the participant’s total annual compensation.
The 2000 LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unit-based compensation, number of units authorized	3,250,000
Unit-based compensation, number of units available to be awarded	1,260,634
The 2006 LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unit-based compensation, number of units authorized	2,000,000
Unit-based compensation, number of units available to be awarded	1,492,327