Segments and Geographic Area Analysis - Summary of Information about Disaggregated Revenue by Primary Geographical Market (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Total revenues	$ 233,542	$ 295,510
Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	226,697	287,926
Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	6,845	7,584
United States [Member]
Segment Reporting Information [Line Items]
Total revenues	140,578	166,576
United States [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	138,632	164,439
United States [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	1,946	2,137
South America [Member]
Segment Reporting Information [Line Items]
Total revenues	53,314	54,269
South America [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	53,284	54,268
South America [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	30	1
Europe [Member]
Segment Reporting Information [Line Items]
Total revenues	26,516	12,770
Europe [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	24,609	11,392
Europe [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	1,907	1,378
Australia [Member]
Segment Reporting Information [Line Items]
Total revenues	13,134
Australia [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	10,172
Australia [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 2,962
Australia/Asia [Member]
Segment Reporting Information [Line Items]
Total revenues		61,895
Australia/Asia [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues		57,827
Australia/Asia [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues		$ 4,068