Commitments And Contingencies - Narrative (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
Mar. 31, 2014
Loss Contingencies
Long-term other receivable related to service taxes	$ 11.8
Indian Tax Authority
Loss Contingencies
Service taxes paid	10.5
Accrued additional service tax	1.3
Total service taxes	$ 11.8

Accounts Receivable, Net, Noncurrent, Service Taxes

No definition available.

Name:	atw_AccountsReceivableNetNoncurrentServiceTaxes
Namespace Prefix:	atw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant