Segments and Geographic Area Analysis - Summary of Information about Disaggregated Revenue by Country (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Total revenues	$ 138,257	$ 254,020	$ 565,630	$ 704,268
Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	129,345	242,315	535,848	676,284
Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	8,912	11,705	29,782	27,984
United States [Member]
Segment Reporting Information [Line Items]
Total revenues	60,092	112,333	253,576	371,936
United States [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	57,523	110,854	244,578	366,907
United States [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	2,569	1,479	8,998	5,029
Brazil [Member]
Segment Reporting Information [Line Items]
Total revenues	25,790	49,336	145,897	131,765
Brazil [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	25,774	49,326	145,921	131,748
Brazil [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	16	10	(24)	17
United Kingdom [Member]
Segment Reporting Information [Line Items]
Total revenues	27,376	53,193	94,024	122,053
United Kingdom [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	25,178	49,341	86,949	113,364
United Kingdom [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	2,198	3,852	7,075	8,689
Australia [Member]
Segment Reporting Information [Line Items]
Total revenues	18,849	39,158	60,345	78,514
Australia [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	16,279	32,794	49,663	64,265
Australia [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	2,570	$ 6,364	10,682	$ 14,249
Malaysia [Member]
Segment Reporting Information [Line Items]
Total revenues	6,150		11,788
Malaysia [Member] | Contract Drilling [Member]
Segment Reporting Information [Line Items]
Total revenues	4,591		8,737
Malaysia [Member] | Reimbursable Expenses [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 1,559		$ 3,051