(7) Equity Investment in Sunrise Energy (Detail) - Condensed Statement of Operations (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Revenue	$ 141,323	$ 157,354
Expenses	(106,848)	(100,614)
Net income	23,807	35,809
Sunrise Energy Segment [Member]
Revenue	2,450	3,951
Expenses	(2,117)	(2,107)
Net income	$ 333	$ 1,844

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

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Reference 16: http://www.xbrl.org/2003/role/presentationRef

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+ Details