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Employee benefit plan (Detail) - Schedule of substantially funded (USD $)
In Thousands, unless otherwise specified |
Jul. 31, 2012
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Dec. 31, 2011
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Jul. 31, 2011
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Dec. 31, 2010
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Dec. 31, 2009
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| Total Assets | $ 69,123 | $ 3,247,099 | $ 109,474 | $ 3,080,281 | $ 2,802,496 |
| Accumulated Benefit Obligation | $ 3,224,370 | $ 3,083,361 | $ 2,754,853 | ||
| Funded status | 99.30% | 100.10% | 98.30% |
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- Definition
Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
For defined benefit pension plans, the actuarial present value of benefits (whether vested or nonvested) attributed by the pension benefit formula to employee service rendered before a specified date and based on employee service and compensation (if applicable) before that date. The accumulated benefit obligation differs from the projected benefit obligation in that it includes no assumption about future compensation levels. For plans with flat-benefit or nonpay-related pension benefit formulas, the accumulated benefit obligation and the projected benefit obligation are the same. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Plan assets of a defined benefit plan, as a percentage of projected benefit obligation. No definition available.
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