XML 55 R40.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Income Taxes (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2015
Income Tax Disclosure [Abstract] |
Summary of Effective Income Tax Rates | The components of income from continuing operations before income taxes for each of the three years ended December 31, 2015 and income tax expense (benefit) attributable thereto were as follows:
| Years Ended December 31,
(Thousands of dollars) | 2015 |  | 2014 |  | 2013
Income (loss) from continuing operations before income taxes | $ | 218,289 |  |  | $ | 339,346 |  |  | $ | 254,194 |
Income tax expense (benefit) |  |  |  |  |
Federal - Current | $ | 58,039 |  |  | 119,338 |  |  | 92,828 |
Federal - Deferred | 15,853 |  |  | (382 | ) |  | (9,067 | )
State - Current and deferred | 6,806 |  |  | (2,570 | ) |  | 16,298 |
Total | $ | 80,698 |  |  | $ | 116,386 |  |  | $ | 100,059 |
Schedule of Reconciliation of Income Taxes to Statutory Rate | The following table reconciles income taxes based on the U.S. statutory tax rate to the Company’s income tax expense.
| Years Ended December 31,
(Thousands of dollars) | 2015 |  | 2014 |  | 2013
Income tax expense based on the U.S. statutory tax rate | $ | 76,401 |  |  | $ | 118,771 |  |  | $ | 88,968 |
State income taxes, net of federal benefit | 4,424 |  |  | (1,671 | ) |  | 10,594 |
Other, net | (127 | ) |  | (714 | ) |  | 497 |
Total | $ | 80,698 |  |  | $ | 116,386 |  |  | $ | 100,059 |
Summary of Deferred Tax Assets and Deferred Tax Liabilities | An analysis of the Company’s deferred tax assets and deferred tax liabilities at December 31, 2015 and 2014 showing the tax effects of significant temporary differences follows:
| December 31,
(Thousands of dollars) | 2015 |  | 2014
Deferred tax assets |  |  |
Property costs and asset retirement obligations | $ | 2,666 |  |  | $ | 2,157 |
Employee benefits | 9,647 |  |  | 9,712 |
Other deferred tax assets | 7,297 |  |  | 8,995 |
Total gross deferred tax assets | 19,610 |  |  | 20,864 |
Less valuation allowance | — |  |  | — |
Net deferred tax assets | 19,610 |  |  | 20,864 |
Deferred tax liabilities |  |  |
Accumulated depreciation and amortization | (157,322 | ) |  | (133,535 | )
State deferred taxes | (17,042 | ) |  | (16,855 | )
Other deferred tax liabilities | (8,211 | ) |  | (8,837 | )
Total gross deferred tax liabilities | (182,575 | ) |  | (159,227 | )
Net deferred tax liabilities | $ | (162,965 | ) |  | $ | (138,363 | )
Reconciliation of Beginning and Ending Liability for Uncertain Tax Positions | No uncertain tax position liabilities were recognized for the year ending December 31, 2013.
| Year Ended December 31,
(Thousands of dollars) | 2015 | 2014
Balance at January 1 | $ | 6,101 |  | $ | — |
Additions for tax positions related to prior year | 222 |  | 10,086 |
Additions for tax positions related to current year | — |  | 77 |
Settlements with taxing authorities | — |  | (1,563 | )
Expiration of statutes of limitation | (873 | ) | (2,499 | )
Balance at December 31 | $ | 5,450 |  | $ | 6,101 |

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

X
- Definition Tabular disclosure of the components of income tax expense attributable to continuing operations for each year presented including, but not limited to: current tax expense (benefit), deferred tax expense (benefit), investment tax credits, government grants, the benefits of operating loss carryforwards, tax expense that results from allocating certain tax benefits either directly to contributed capital or to reduce goodwill or other noncurrent intangible assets of an acquired entity, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity, and adjustments of the beginning-of-the-year balances of a valuation allowance because of a change in circumstances that causes a change in judgment about the realizability of the related deferred tax asset in future years. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319 + Details
Name: | us-gaap_ScheduleOfComponentsOfIncomeTaxExpenseBenefitTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the components of net deferred tax asset or liability recognized in an entity's statement of financial position, including the following: the total of all deferred tax liabilities, the total of all deferred tax assets, the total valuation allowance recognized for deferred tax assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319 + Details
Name: | us-gaap_ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319 + Details
Name: | us-gaap_ScheduleOfEffectiveIncomeTaxRateReconciliationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the change in unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 55 -Paragraph 217 -URI http://asc.fasb.org/extlink&oid=51663037&loc=d3e36027-109320 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -URI http://asc.fasb.org/extlink&oid=6907707&loc=SL6600010-109319 + Details
Name: | us-gaap_ScheduleOfUnrecognizedTaxBenefitsRollForwardTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration