Supplemental Cash Flow Information (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Changes in operating assets and liabilities
Accounts receivable	$ (68,914)	$ (21,820)	$ 64,886
Prepaid expenses and other assets	(8,225)	12,719	35,006
Accounts payable	(12,216)	11,002	2,731
Accrued and other liabilities	(19,424)	65,518	26,240
Other long-term liabilities			25,254
Total	$ (84,347)	$ 45,415	$ 148,655

The increase (decrease) during the reporting period in the aggregate amount of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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- Definition

The increase (decrease) during the reporting period in amount due within one year (or one business cycle) from customers for the credit sale of goods and services.

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- Definition

The increase (decrease) during the reporting period in the aggregate amount of accrued expenses and other operating obligations not separately disclosed in the statement of cash flows.

+ References

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- Definition

The increase (decrease) during the reporting period of all assets and liabilities used in operating activities.

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- Definition

The increase (decrease) during the reporting period in other noncurrent operating liabilities not separately disclosed in the statement of cash flows.

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- Definition

The increase (decrease) during the reporting period in the value of prepaid expenses and other assets not separately disclosed in the statement of cash flows, for example, deferred expenses, intangible assets,or income taxes.

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