v3.8.0.1
Income Taxes - Total Income Tax Expense Differed from Amounts Computed by Applying U.S. Federal Statutory Tax Rates to Pre-Tax Income (Detail) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
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, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]                              
Statutory tax at 35%                         $ (12,578) $ (26,831) $ (93,628)
State taxes, net of federal impact                         528 578 (1,463)
Share-based compensation tax shortfall                         1,279 1,826 1,939
Permanent differences                         11 11 26
Other differences                         30 (2) (1,035)
Change in federal tax rate                         (51,939)    
Write-off of deferred tax assets                         139,090   756
Total $ (53,512) $ (4,258) $ (4,509) $ 138,700 $ (3,571) $ (4,915) $ (8,687) $ (7,245) $ (284) $ (81,756) $ (7,369) $ (3,996) $ 76,421 $ (24,418) $ (93,405)