XML 59 R49.htm IDEA: XBRL DOCUMENT v3.19.2
Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Line Items]          
Increase in goodwill     $ 2,104,000    
Amortization expense on intangible assets $ 3,700,000 $ 4,900,000 7,300,000 $ 10,300,000  
Contract Drilling          
Goodwill And Intangible Assets Disclosure [Line Items]          
Accumulated impairment losses 0   0   $ 0
Other Operations          
Goodwill And Intangible Assets Disclosure [Line Items]          
Increase in goodwill     2,104,000    
Accumulated impairment losses $ 0   $ 0   $ 0