XML 141 R117.htm IDEA: XBRL DOCUMENT v3.8.0.1
Income Taxes - Narrative (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Apr. 01, 2015
Income Taxes [Line Items]        
Net operating loss carryovers $ 1,600,000      
Tax Cuts and Jobs Act of 2017, change in tax rate, deferred tax asset, provisional income tax expense (benefit) 207,700      
Tax Cuts and Jobs Act of 2017, provisional income tax benefit 800      
Deferred tax asset, increase (decrease)   $ 59,000    
Income (loss) before income taxes, foreign 0 1,400 $ 900  
Alternative minimum tax credit carryovers $ 1,600      
Minimum        
Income Taxes [Line Items]        
Net operating loss carryforwards expiration year 2027      
Maximum        
Income Taxes [Line Items]        
Net operating loss carryforwards expiration year 2036      
Mid Pac Petroleum, LLC        
Income Taxes [Line Items]        
Deferred tax liability     $ 16,800 $ 16,759
5% Convertible Senior Notes due 2021        
Income Taxes [Line Items]        
Deferred tax asset, increase (decrease)   $ 8,600