Basis of Presentation and Nature of Operations (Details)	6 Months Ended
	Jun. 30, 2013 drilling_unit
Oil and Gas Delivery Commitments and Contracts [Line Items]
Number of fleet of self-elevating mobile offshore jack-up drilling units	30
Number of ultra-deepwater drill ships under construction	4
Rowan Renaissance [Member]
Oil and Gas Delivery Commitments and Contracts [Line Items]
Ultra-deepwater drill ships expected to be completed, contract term after delivery	3 years
Rowan Resolute [Member]
Oil and Gas Delivery Commitments and Contracts [Line Items]
Ultra-deepwater drill ships expected to be completed, contract term after delivery	3 years
Rowan Reliance [Member]
Oil and Gas Delivery Commitments and Contracts [Line Items]
Ultra-deepwater drill ships expected to be completed, contract term after delivery	3 years