Goodwill by Operating Segment (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2017 USD ($)
Goodwill [Line Items]
Balance at beginning of period	$ 86,234
Changes to goodwill	438,466
Balance at end of period	524,700
Contract Drilling
Goodwill [Line Items]
Balance at beginning of period	86,234
Changes to goodwill	300,819
Balance at end of period	387,053
Pressure Pumping
Goodwill [Line Items]
Changes to goodwill	137,647
Balance at end of period	$ 137,647