Commitments and Contingencies (Details) - USD ($) $ in Millions	Apr. 28, 2015	Jun. 30, 2016
Purchase obligations
Purchase orders outstanding for drilling equipment		$ 4.9
Gain contingencies recognized in consolidated financial statements		$ 0.0
Pending litigation \| Minimum \| Keel accident case
Commitments and Contingencies
Damages value	$ 100.0

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
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-Section 50
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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