Annual report pursuant to Section 13 and 15(d)

Schedule II - Valuation and Qualifying Accounts (Detail)

v3.6.0.2
Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Allowance for doubtful accounts and notes [Member]      
Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at beginning of year $ 8,694 $ 11,188 $ 12,853
Charged to cost and expenses 1,483 341 5,248
Charged to other accounts 4 (825) 0
Deductions (1,922) (2,010) (6,913)
Balance at end of year 8,259 8,694 11,188
Allowance for obsolete rig materials and supplies [Member]      
Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at beginning of year 626 530 3,445
Charged to cost and expenses 978 0 0
Charged to other accounts (3) 236 1
Deductions (435) (140) (2,916)
Balance at end of year 1,166 626 530
Deferred tax valuation allowance [Member]      
Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at beginning of year 51,105 9,922 6,827
Charged to cost and expenses 117,707 40,676 2,800
Charged to other accounts 2,321 507 295
Deductions 0 0 0
Balance at end of year $ 171,133 $ 51,105 $ 9,922