Document And Entity Information - shares shares in Thousands	9 Months Ended
	Jun. 30, 2015	Jul. 27, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	ATWOOD OCEANICS INC
Entity Central Index Key	0000008411
Current Fiscal Year End Date	--09-30
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		64,653
Trading Symbol	atw