Nontrade Receivables and Allowance for Credit Losses (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Nontrade receivables	$ 7,277,776	$ 6,239,870
Allowance for credit losses	(41,486)	(72,967)	(92,142)
Non Trade Receivable
Financing Receivable, Allowance for Credit Losses [Line Items]
Nontrade receivables	30,272	28,789
Allowance for credit losses	(6,486)	(6,217)	(6,892)
Net nontrade receivables	23,786	22,572
Agents \| Non Trade Receivable
Financing Receivable, Allowance for Credit Losses [Line Items]
Nontrade receivables	11,557	9,681
Allowance for credit losses	(4,981)	(4,712)
Net nontrade receivables	6,576	4,969
Reinsurer \| Non Trade Receivable
Financing Receivable, Allowance for Credit Losses [Line Items]
Nontrade receivables	18,715	19,108
Allowance for credit losses	(1,505)	(1,505)
Net nontrade receivables	$ 17,210	$ 17,603

A valuation allowance for financing receivables that are expected to be uncollectible.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

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- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

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- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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