PROPERTY AND EQUIPMENT (Narrative) (Details) (USD $)											12 Months Ended
	Sep. 30, 2008 Delivered, Newbuild Drilling Units [Member] Atwood Osprey [Member] DrillingUnit	Sep. 30, 2008 Delivered, Newbuild Drilling Units [Member] Atwood Condor [Member] DrillingUnit	Sep. 30, 2011 Delivered, Newbuild Drilling Units [Member] Atwood Mako [Member] DrillingUnit	Sep. 30, 2011 Delivered, Newbuild Drilling Units [Member] Atwood Manta [Member] DrillingUnit	Sep. 30, 2011 Delivered, Newbuild Drilling Units [Member] Atwood Orca [Member] DrillingUnit	Sep. 30, 2013 Construction in Progress, Newbuild Drilling Units [Member] DrillingUnit	Jan. 31, 2011 Construction in Progress, Newbuild Drilling Units [Member] Atwood Advantage [Member] DrillingUnit	Oct. 31, 2011 Construction in Progress, Newbuild Drilling Units [Member] Atwood Achiever [Member] DrillingUnit	Sep. 30, 2012 Construction in Progress, Newbuild Drilling Units [Member] Atwood Admiral [Member] DrillingUnit	Jun. 30, 2013 Construction in Progress, Newbuild Drilling Units [Member] Atwood Archer [Member] DrillingUnit	Sep. 30, 2013 Capital Addition Purchase Commitments [Member] Construction in Progress, Newbuild Drilling Units [Member]
Property, Plant and Equipment [Line Items]
Number of drilling units	1	1	1	1	1	4	1	1	1	1
Expenditure towards construction of drilling units currently under construction						$ 732,000,000
Commitments on drilling units under construction											$ 1,500,000,000