Major Customers (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Revenue, Major Customer [Line Items]
Revenue	$ 155,845	$ 141,694	$ 134,787	$ 163,498	$ 224,492	$ 206,052	$ 145,548	$ 187,637	$ 595,824	[1]	$ 763,729	[1]	$ 558,134	[1]
Revenue
Revenue, Major Customer [Line Items]
Number of major customers											3		3
Geographic Concentration Risk | Revenue | Latin America
Revenue, Major Customer [Line Items]
Concentration risk									29.00%		15.00%		10.00%
Customer Concentration Risk | Customer One
Revenue, Major Customer [Line Items]
Number of major customers									1
Customer Concentration Risk | Customer Two
Revenue, Major Customer [Line Items]
Number of major customers									1
Customer Concentration Risk | Customer Three
Revenue, Major Customer [Line Items]
Number of major customers									1
Customer Concentration Risk | Customer Four
Revenue, Major Customer [Line Items]
Number of major customers											1
Customer Concentration Risk | Customer Five
Revenue, Major Customer [Line Items]
Number of major customers											1
Customer Concentration Risk | Customer Six
Revenue, Major Customer [Line Items]
Number of major customers													1
Customer Concentration Risk | Revenue | Largest Three Customers
Revenue, Major Customer [Line Items]
Concentration risk									45.00%		29.00%		25.00%
Number of major customers									3
Revenue									$ 267,900		$ 223,100		$ 138,000
Customer Concentration Risk | Revenue | Customer One
Revenue, Major Customer [Line Items]
Concentration risk									29.00%
Customer Concentration Risk | Revenue | Customer Two
Revenue, Major Customer [Line Items]
Concentration risk									11.00%
Customer Concentration Risk | Revenue | Customer Three
Revenue, Major Customer [Line Items]
Concentration risk									5.00%
Customer Concentration Risk | Revenue | Customer Four
Revenue, Major Customer [Line Items]
Concentration risk											4.00%
Customer Concentration Risk | Revenue | Customer Five
Revenue, Major Customer [Line Items]
Concentration risk											15.00%
Customer Concentration Risk | Revenue | Customer Six
Revenue, Major Customer [Line Items]
Concentration risk													10.00%
Customer Concentration Risk | Accounts Receivable | Customer One
Revenue, Major Customer [Line Items]
Concentration risk									16.00%
Customer Concentration Risk | Accounts Receivable | Customer Two
Revenue, Major Customer [Line Items]
Concentration risk									2.00%
Customer Concentration Risk | Accounts Receivable | Customer Three
Revenue, Major Customer [Line Items]
Concentration risk									15.00%
Customer Concentration Risk | Accounts Receivable | Customer Four
Revenue, Major Customer [Line Items]
Concentration risk											13.00%
Customer Concentration Risk | Accounts Receivable | Customer Five
Revenue, Major Customer [Line Items]
Concentration risk											9.00%
Customer Concentration Risk | Accounts Receivable | Customer Six
Revenue, Major Customer [Line Items]
Concentration risk													7.00%

[1] During the fourth quarter of 2010, the Company re-assessed its operating segments and concluded that its multi-client data library business is a separate operating segment. Accordingly, prior periods have been restated.