Goodwill by Operating Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Balance at beginning of period	$ 86,234	$ 210,795
Changes to goodwill	0	(124,561)
Balance at end of period	86,234	86,234
Contract Drilling
Goodwill [Line Items]
Balance at beginning of period	86,234	86,234
Changes to goodwill	0	0
Balance at end of period	86,234	86,234
Pressure Pumping
Goodwill [Line Items]
Balance at beginning of period	0	124,561
Changes to goodwill	0	(124,561)
Balance at end of period	$ 0	$ 0