Segments and Geographic Area Analysis - Long-Lived Tangible Assets by Country (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net	$ 1,175,895	$ 4,122,809	$ 5,152,828
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net	559,288	2,162,488	2,227,934
Senegal [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net	188,694
Spain [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net	142,930	686,436
Australia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net	106,173	722,389	570,964
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net	98,338	248,500	1,061,585
Brazil [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net	76,383	87,543	883,607
Myanmar [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net	2,258	207,451
Singapore [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net		5,819	404,420
Other Countries [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net	1,831	2,183	4,318
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Drilling and other property and equipment, net	$ 616,607	$ 1,960,321	$ 2,924,894