Schedule II - Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance, valuation allowance	$ 748,283	$ 765,023	$ 656,352
Allowance for doubtful trade accounts receivable [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance, valuation allowance	1,000	734	734	734
Charged to Cost and Expense	0	0	0
Charged to Other Accounts	266	0	0
Deductions	0	0	0
Deferred tax asset - valuation allowance [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance, valuation allowance	748,283	765,023	656,352	773,714
Charged to Cost and Expense	0	0	0
Charged to Other Accounts	(16,740)	108,671	(117,362)
Deductions	$ 0	$ 0	$ 0

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.

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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