Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, valuation allowance	$ 748,283	$ 765,023
Balance, valuation allowance	768,764	748,283	$ 765,023
Allowance for doubtful trade accounts receivable [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, valuation allowance	1,000	734	734
Charged to Cost and Expense	0	0	0
Charged to Other Accounts	0	266	0
Deductions	0	0	0
Balance, valuation allowance	1,000	1,000	734
Deferred tax asset - valuation allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance, valuation allowance	748,283	765,023	656,352
Charged to Cost and Expense	0	0	0
Charged to Other Accounts	20,481	(16,740)	108,671
Deductions	0	0	0
Balance, valuation allowance	$ 768,764	$ 748,283	$ 765,023

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 09
-Article 12

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Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

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