Segments and Geographic Area Analysis - Summary of Information about Disaggregated Revenue by Primary Geographical Market (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total revenues	$ 254,020	$ 286,322	$ 704,268	$ 850,693
Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	242,315	280,691	676,284	833,970
Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	11,705	5,631	27,984	16,723
United States [Member]
Segment Reporting Information [Line Items]
Total revenues	112,333	157,611	371,936	487,561
United States [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	110,854	155,695	366,907	482,337
United States [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	1,479	1,916	5,029	5,224
South America [Member]
Segment Reporting Information [Line Items]
Total revenues	49,336	49,378	131,765	129,935
South America [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	49,326	49,410	131,748	129,966
South America [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	10	(32)	17	(31)
Europe [Member]
Segment Reporting Information [Line Items]
Total revenues	53,193	32,805	122,053	66,054
Europe [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	49,341	30,809	113,364	60,938
Europe [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	3,852	1,996	8,689	5,116
Australia [Member]
Segment Reporting Information [Line Items]
Total revenues	39,158		78,514
Australia [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	32,794		64,265
Australia [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 6,364		$ 14,249
Australia/Asia [Member]
Segment Reporting Information [Line Items]
Total revenues		46,528		167,143
Australia/Asia [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues		44,777		160,729
Australia/Asia [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues		$ 1,751		$ 6,414