Summary Of Significant Accounting Policies (Summary Of Changes In The Carrying Amount Of Goodwill) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2008
Goodwill [Line Items]
Goodwill, beginning balance		$ 62,494		$ 78,643	[1]	$ 704,300
Goodwill impairments	(16,700)			(16,743)	[2]
Other adjustments		(279)	[3]	594	[3]
Goodwill, ending balance	62,494	62,215		62,494		704,300
Reservoir Consulting Business [Member]
Goodwill [Line Items]
Goodwill, beginning balance						8,300
Goodwill, ending balance						$ 8,300

[1] Prior to 2009, we fully impaired our oil and gas related goodwill ($704.3 million) as well as the $8.3 million of goodwill associated with our former reservoir consulting business.

[2] Amount reflects full write off of goodwill associated with our WOSEA operations.

[3] Reflects foreign currency adjustment for certain amounts of our goodwill.