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Schedule of Activity of Allowance for Uncollectible Accounts on Agent Receivables (Detail) (Uncollectible receivables, USD $)
In Thousands, unless otherwise specified |
9 Months Ended | 12 Months Ended | 9 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|---|---|
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Sep. 30, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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Sep. 30, 2012
Additions
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Dec. 31, 2011
Additions
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Sep. 30, 2012
Deductions
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Dec. 31, 2011
Deductions
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| Financing Receivable, Allowance for Credit Losses [Line Items] | |||||||
| Allowance for uncollectible accounts on agent receivables, Beginning of year | $ 2,209 | $ 2,226 | $ 644 | ||||
| Financing receivable, allowance for credit losses, period increase (decrease) | 177 | 1,724 | (194) | (142) | |||
| Allowance for uncollectible accounts on agent receivables, End of year | $ 2,209 | $ 2,226 | $ 644 |