Equity-Method Investments (Details) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended			1 Months Ended		2 Months Ended		1 Months Ended	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011	Apr. 30, 2012 Dynamic Offshore acquired by SandRidge Energy Inc. [member]	Apr. 30, 2012 SandRidge [Member]	Feb. 28, 2011 SPN Resources [Member]	Feb. 28, 2011 DBH [Member]	Mar. 31, 2011 Dynamic Offshore [Member]	Mar. 31, 2012 Dynamic Offshore [Member]	Dec. 31, 2011 Dynamic Offshore [Member]
Equity-Method Investments (Textual) [Abstract]
Percentage of limited partnership interest								10.00%
Equity-method investments	$ 69,552,000		$ 72,472,000						$ 67,800,000	$ 70,600,000
Earnings (losses) from equity-method investments, net	(287,000)	27,000				200,000	900,000	1,100,000	300,000
Revenue from equity-method investment						300,000	900,000	2,200,000	15,500,000
Receivable from Dynamic Offshore									12,300,000	9,800,000
Receivable from Dynamic Offshore related to oil and natural gas commodity sales and production									13,600,000	14,000,000
Equity-Method Investments (Additional Textual) [Abstract]
Cash Consideration to be Paid for Dynamic Offshore				34,100,000
Share Issuable in Acquisition of Dynamic Offshore				7.0
Gain loss from Equity method investment					$ 19,000,000