v3.26.1
PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Sep. 30, 2025
Property, Plant, and Equipment [Line Items]    
Property, plant and equipment, gross $ 9,146,307 $ 9,578,912
Accumulated depreciation (5,280,975) (5,265,838)
Property, plant and equipment, net 3,865,332 4,313,074
Assets held-for-sale 12,659 15,231
Drilling services equipment    
Property, Plant, and Equipment [Line Items]    
Property, plant and equipment, gross $ 7,728,614 8,168,906
Drilling services equipment | Minimum    
Property, Plant, and Equipment [Line Items]    
Estimated Useful Lives 2 years  
Drilling services equipment | Maximum    
Property, Plant, and Equipment [Line Items]    
Estimated Useful Lives 15 years  
Tubulars    
Property, Plant, and Equipment [Line Items]    
Estimated Useful Lives 4 years  
Property, plant and equipment, gross $ 616,790 597,933
Real estate properties    
Property, Plant, and Equipment [Line Items]    
Property, plant and equipment, gross $ 5,613 8,223
Real estate properties | Minimum    
Property, Plant, and Equipment [Line Items]    
Estimated Useful Lives 10 years  
Real estate properties | Maximum    
Property, Plant, and Equipment [Line Items]    
Estimated Useful Lives 45 years  
Other    
Property, Plant, and Equipment [Line Items]    
Property, plant and equipment, gross $ 634,193 620,908
Other | Minimum    
Property, Plant, and Equipment [Line Items]    
Estimated Useful Lives 2 years  
Other | Maximum    
Property, Plant, and Equipment [Line Items]    
Estimated Useful Lives 23 years  
Construction in progress    
Property, Plant, and Equipment [Line Items]    
Property, plant and equipment, gross $ 161,097 $ 182,942