| Components of Income Tax Expense (Detail) (USD $) In Thousands, unless otherwise specified | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 | |
| Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] | |||
| Current | $ (2,146) | $ (40,562) | $ 29,682 | 
| Deferred | 30,920 | 88,109 | 61,835 | 
| Income tax expense (benefit) | $ 28,774 | $ 47,547 | $ 91,517 | 
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- Details 
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- Definition Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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