XML 68 R52.htm IDEA: XBRL DOCUMENT v3.8.0.1
Income Taxes (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Effect of Tax Cuts and Jobs Act of 2017, Accounting Incomplete, Provisional [Abstract]            
Tax Cuts and Jobs Act of 2017 Accounting Complete [true false]       false    
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent       35.00% 35.00% 35.00%
Tax Cuts and Jobs Act of 2017 Incomplete Accounting Provisional Income Tax Expense (Benefit) $ (8,100)     $ (8,100)    
Pretax income (loss) from domestic and foreign sources [Abstract]            
Domestic       115,083 $ 41,703 $ 79,414
Foreign       2,505 1,598 1,268
Income before income taxes       117,588 43,301 80,682
Deferred income tax provision (benefit) [Abstract]            
Federal       22,541 10,664 (2,938)
State       3,973 2,201 555
Foreign       0 5 0
Total current       26,514 12,870 (2,383)
Federal       6,747 2,549 27,011
State       991 (1,536) 3,872
Foreign       379 (8,836) 0
Total deferred       8,117 (7,823) 30,883
Income tax provision       34,631 5,047 28,500
Income Tax Rate Reconciliation [Abstract]            
Income before income taxes       $ 117,588 $ 43,301 $ 80,682
Statutory U.S. income tax rate (as a percent)       35.00% 35.00% 35.00%
Statutory tax provision       $ 41,156 $ 15,155 $ 28,239
State taxes       3,719 1,370 3,006
Domestic production activities deduction       (963) (165) (299)
Unrecognized tax benefits       (86) 1,717 433
Benefit from enactment of the Tax Cuts and Jobs Act       (8,129) 0 0
Change in valuation allowance   $ (8,500)   0 [1] (9,884) [1] 0 [1]
Tax credits       (912) (2,904) (2,043)
Other       (154) (242) (836)
Income tax provision       $ 34,631 $ 5,047 $ 28,500
Effective income tax rate (as a percent)       29.50% 11.70% 35.30%
Increase (decrease) in valuation allowance         $ (9,900)  
Income taxes paid, net       $ 36,100 6,700 $ 700
Deferred tax assets [Abstract]            
Employee benefits 30,853 54,895   30,853 54,895  
Inventories 4,598 5,237   4,598 5,237  
Other 6,003 7,628   6,003 7,628  
Net deferred tax assets 46,591 73,143   46,591 73,143  
Deferred tax liabilities [Abstract]            
Property and equipment (47,946) (62,948)   (47,946) (62,948)  
Intangible assets and other (4,168) (5,039)   (4,168) (5,039)  
Other (1,867) (2,655)   (1,867) (2,655)  
Deferred tax liabilities (53,981) (70,642)   (53,981) (70,642)  
Total deferred tax liabilities, net (7,390)     (7,390)    
Total deferred tax assets, net   2,501     2,501  
Reconciliation of unrecognized tax benefits, roll forward            
Balance as of January 1     $ 2,083 2,224 878 309
Increases related to prior years' tax positions       1 1,657 431
Increases related to current year tax positions       51 104 145
Decreases related to prior years' tax positions       (12) 0 (7)
Lapse of statute of limitations       (181) 0 0
Settlements       0 (415) 0
Balance as of December 31 2,083 2,224   2,083 2,224 878
Unrecognized tax benefits that would impact tax rate 2,000 2,100   2,000 2,100 $ 700
State and Local Jurisdiction [Member]            
Deferred tax liabilities [Abstract]            
State income tax credits, subject to expiration 1,600     1,600    
CANADA | Subsidiaries [Member]            
Deferred tax assets [Abstract]            
Foreign net operating loss carryforward 5,137 $ 5,383   5,137 $ 5,383  
Deferred tax liabilities [Abstract]            
Foreign net operating loss carryforwards, subject to expiration $ 23,300     $ 23,300    
Scenario, Forecast [Member]            
Effect of Tax Cuts and Jobs Act of 2017, Accounting Incomplete, Provisional [Abstract]            
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent     21.00%      
Income Tax Rate Reconciliation [Abstract]            
Statutory U.S. income tax rate (as a percent)     21.00%      
[1] Deferred tax assets in our foreign subsidiaries are primarily the result of net operating losses. As of each reporting date, management considers new evidence, both positive and negative, that could affect its view of the future realization of deferred tax assets. During fourth quarter 2016, because we achieved three years of cumulative pretax income in the Canadian tax jurisdiction and due to the implementation of a tax-planning strategy, management determined that there is sufficient positive evidence to conclude that it is more likely than not that the deferred tax assets are realizable and therefore released the valuation allowance in the amount of $9.9 million.