v3.6.0.2

Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Quarterly Financial Data |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total revenues | $ 319 |  | $ 308 |  | $ 293 |  | $ 300 |  | $ 292 |  | $ 282 |  | $ 275 |  | $ 263 |  | $ 1,220 |  | $ 1,112 |  | $ 600
Operating expenses | 128 |  | 113 |  | 113 |  | 117 |  | 135 |  | 117 |  | 115 |  | 101 |  | 471 |  | 468 |  | 324
Operating income | 123 |  | 127 |  | 118 |  | 119 |  | 97 |  | 100 |  | 97 |  | 99 |  | 487 |  | 393 |  | 164
Net earnings (loss) | 73 |  | 81 |  | 76 |  | 85 |  | 59 |  | 65 |  | 60 |  | 65 |  | 315 |  | 249 |  | 56
Limited partners’ interest in net earnings | $ 32 |  | $ 48 |  | $ 47 |  | $ 60 |  | $ 46 |  | $ 54 |  | $ 49 |  | $ 50 |  | $ 187 |  | $ 199 |  | $ 56
Net earnings (loss) per limited partner unit: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common - basic (dollars per unit) | $ 0.31 | [1] | $ 0.46 | [1] | $ 0.48 | [1] | $ 0.64 | [1] | $ 0.49 | [1] | $ 0.62 | [1] | $ 0.60 | [1] | $ 0.63 | [1] | $ 1.87 | [1] | $ 2.33 | [1] | $ 0.96
Common - diluted (dollars per unit) | $ 0.31 | [1] | $ 0.46 | [1] | $ 0.48 | [1] | $ 0.64 | [1] | $ 0.49 | [1] | $ 0.62 | [1] | $ 0.60 | [1] | $ 0.63 | [1] | $ 1.87 | [1] | $ 2.33 | [1] | $ 0.96
[1] | The sum of four quarters may not equal annual results due to rounding or the quarterly number of units outstanding.

X
- References No definition available. + Details
Name: | us-gaap_EarningsPerShareBasicAndDilutedAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Net Income -URI http://asc.fasb.org/extlink&oid=51831255 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(22)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(18)) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Other Comprehensive Income -URI http://asc.fasb.org/extlink&oid=51831270 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(20)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_NetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Aggregate amount of net income allocated to limited partners. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770 + Details
Name: | us-gaap_NetIncomeLossAllocatedToLimitedPartners
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Per unit of ownership amount after tax of income (loss) available to limited partnership (LP) unit-holder and units that would have been outstanding assuming the issuance of limited partner units for dilutive potential units outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB Topic 4.F) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770 + Details
Name: | us-gaap_NetIncomeLossNetOfTaxPerOutstandingLimitedPartnershipUnitDiluted
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Per unit of ownership amount after tax of income (loss) available to outstanding limited partnership (LP) unit-holder. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 5 -Subparagraph (SAB Topic 4.F) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770 + Details
Name: | us-gaap_NetIncomeLossPerOutstandingLimitedPartnershipUnitBasicNetOfTax
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Excludes Selling, General and Administrative Expense. + References No definition available. + Details
Name: | us-gaap_OperatingCostsAndExpenses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The net result for the period of deducting operating expenses from operating revenues. + References No definition available. + Details
Name: | us-gaap_OperatingIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_QuarterlyFinancialDataAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_SalesRevenueNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration