Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically common stock), at the option of the issuer or the holder.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

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-Section S99

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-Subparagraph (SX 210.7-03.16(a))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-Publisher SEC

-Name Regulation S-X (SX)

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-Section 02

-Paragraph 20, 22

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- Definition

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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-Name Accounting Principles Board Opinion (APB)

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Carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion. Senior note holders are paid off in full before any payments are made to junior note holders.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

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Carrying value as of the balance sheet date of the portion of long-term notes having the highest claim on the assets of the issuer in case of bankruptcy or liquidation, due within one year or the normal operating cycle, if longer. Senior note holders are paid off in full before any payments are made to debt holders having a lesser priority of repayment.

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

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Carrying amount at the balance sheet date of borrowings from a creditor other than a bank, not elsewhere specified in the taxonomy, with a maturity within one year (or within one operating cycle if longer) from the date of borrowing.

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-Publisher SEC

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-Subparagraph (SX 210.5-02.19(a)(2))

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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Total Obligations Under Notes (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Senior Secured Notes due 2016 Secured Debt	Dec. 31, 2012 Senior Secured Notes due 2016 Secured Debt	Mar. 07, 2008 Convertible Senior Notes Due 2013	Mar. 31, 2013 Convertible Senior Notes Due 2013 Secured Debt	Dec. 31, 2012 Convertible Senior Notes Due 2013 Secured Debt	Mar. 31, 2013 Senior Notes due March 18, 2013 (New Debt)	Dec. 31, 2012 Senior Notes due March 18, 2013 (New Debt)	Mar. 31, 2013 Senior Notes due March 18, 2013 (New Debt) Secured Debt Roust Trading Limited	Dec. 31, 2012 Senior Notes due March 18, 2013 (New Debt) Secured Debt Roust Trading Limited
Debt Instrument [Line Items]
Convertible Senior Notes (CSN)	$ 257,858	$ 256,922			$ 290,300	$ 257,858	$ 257,858
Senior Secured Notes due 2016 (SSN)	928,658	944,499	931,174	947,127
Unamortized debt discount			(2,516)	(2,628)		0	(148)	(12,700)	(13,600)
Debt discount related to ASC 470-20						0	(788)
Debt Security (RTL Notes)										20,000	70,000
Total	$ 20,000	$ 70,000								$ 20,000	$ 70,000