Consolidated Joint Ventures - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014 Rigs JointVenture	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
Percent of interest in joint ventures	50.00%
Number of joint ventures acquired	2
Number of bully class drillships	2
Dividend paid to joint venture partner	$ 64,000,000	$ 70,000,000
Carrying amount of the drillships	1,400,000,000		1,400,000,000
Cash held by Bully joint venture	68,354,000	178,370,000	114,458,000	282,092,000
Bully Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Dividend paid by Bully Joint Venture Partners	129,000,000	139,000,000
Affiliated Entity [Member]
Schedule of Equity Method Investments [Line Items]
Cash held by Bully joint venture	$ 49,000,000		$ 50,000,000