Annual report pursuant to Section 13 and 15(d)

Summary of Principal Components of Net Deferred Income Tax Liability (Detail)

v3.6.0.2
Summary of Principal Components of Net Deferred Income Tax Liability (Detail) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Deferred tax assets:    
Property and equipment $ 183,303 $ 417,535
Pension and postretirement benefits 710 2,276
Share-based compensation 28 7,393
Net operating loss (“NOL”) carryforwards 87,622 222,971
Deferred Tax Assets, Derivative Instruments 9,579  
Deferred gains 0 30,382
Other 7,166 16,637
Deferred tax assets, gross 288,408 697,194
Less: Valuation allowance (288,408) (662,909)
Total net deferred tax assets 0 34,285
Deferred tax liabilities:    
Fair value of derivative instruments 0 34,285
Deferred tax liabilities, gross 0 34,285
Deferred tax liabilities, net $ 0 $ 0