Commitments and Contingencies (Details) - USD ($) $ in Millions	Mar. 31, 2015	Sep. 30, 2014
COMMITMENTS AND CONTINGENCIES
Purchase orders outstanding for drilling equipment	$ 205.2	$ 412.9
Gain contingencies recognized in consolidated financial statements	$ 0.0	$ 0.0

Amount of gain recognized in the period that had been disclosed in prior periods as a contingent gain.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 30

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6397426&loc=d3e17499-108355

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant