v3.5.0.2

EMPLOYEE BENEFIT PLANS Narrative (Details) - USD ($) $ in Millions |  | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Mar. 01, 2016 | Jun. 30, 2016 | Dec. 31, 2016
Compensation and Retirement Disclosure [Abstract] |  |  |
Pension Plan, description |  | The NuStar Pension Plan (the Pension Plan) is a qualified non-contributory defined benefit pension plan that provides eligible U.S. 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. |
Pension and OPEB assumptions |  | We estimate pension and other postretirement benefit obligations and costs from actuarial valuations. The actuarial valuations require the use of certain assumptions, including discount rates, expected long-term rates of return on plan assets and expected rates of compensation increase. The amortization of actuarial gains and losses reflects a corridor based on 10% of the greater of the projected benefit obligation or the market-related value of the pension plan assets. |
Thrift Plan, description |  | The NuStar Thrift Plan (the Thrift Plan) is a qualified defined contribution plan and participation in the Thrift Plan is voluntary and open to substantially all our 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. We make 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. |
Pension Plans (The Pension Plan and Excess Pension Plan) |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Obligation Assumed | $ 22.5 |  |
Other Postretirement Benefits |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan Obligation Assumed | $ 10.2 |  |
Subsequent Event [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined Benefit Plan, Expected Contributions in Current Fiscal Year |  |  | $ 16.0

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- Definition The liability recorded in the balance sheet, which represents obligations associated with the defined benefit plans and/or other postretirement benefits. This liability is in conjunction with the assignment and transfer of employees from the general partner of our general partner to our wholly owned subsidiary. + References No definition available. + Details
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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. + Details
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- Definition Amount of the employer's best estimate of contributions expected to be paid to the plan in the current fiscal period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2709-114920 + Details
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- Definition General information regarding defined benefit plans. A defined benefit pension plan is a plan that defines an amount of pension benefit to be provided, usually as a function of one or more factors such as age, years of service, or compensation. An other postretirement defined benefit plan is an arrangement that is mutually understood by an employer and its employees, whereby an employer undertakes to provide its employees with benefits other than pensions, after they retire in exchange for their services over a specified period of time, upon attaining a specified age while in service, or a combination of both. Any plan that is not a defined contribution plan is a defined benefit plan. General descriptive information about the employer's defined benefit plans, including employee groups covered, type of benefit formula, type of benefits, cost sharing arrangements, funding policy, types of assets held, and significant nonbenefit liabilities, if any. Also includes information pertaining to multiple employer plans, which are accounted for as single-employer plans. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Defined Benefit Plan -URI http://asc.fasb.org/extlink&oid=49172387 + Details
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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 + Details
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- Definition Description of and general information regarding the types of plans utilized by the employer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2410-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e2417-114920 + Details
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