Reconciliation of Assets Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs Level Three (Detail) (Corporate Securities, USD $) In Thousands, unless otherwise specified | 6 Months Ended | 12 Months Ended |
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Jun. 30, 2012 | Dec. 31, 2011 | |
Corporate Securities | ||
| Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] | ||
| Balance of recurring Level 3 assets at January 1 | $ 1,060 | $ 1,060 |
| Purchases | 0 | 0 |
| Sales | 0 | 0 |
| Issuances | 0 | 0 |
| Settlements | 0 | 0 |
| Transfers into Level 3 | 0 | 0 |
| Transfers out of Level 3 | 0 | 0 |
| Balance of recurring Level 3 assets at December 31 | $ 1,060 | $ 1,060 |
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- Details
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- Definition Issues that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Purchases that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Sales that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Settlements that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Transfers into assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Transfers out of assets measured at fair value and categorized within Level 3 of the fair value hierarchy that have taken place during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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