The liability as of the balance sheet date to the policyholders for deposits held under the terms of insurance contracts.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 97

-Paragraph 15-21

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.13(a)(3))

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 30

-Paragraph 16

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6482265&loc=d3e13951-158433

Name:	us-gaap_PolicyholderContractDeposits
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Schedule of Contractholder Funds (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Policyholder Contract Deposits By Product [Line Items]
Contractholder funds	$ 14,255,844	$ 15,489,624	$ 17,247,071
Interest-sensitive life insurance
Policyholder Contract Deposits By Product [Line Items]
Contractholder funds	4,814,410	4,556,892
Fixed annuities
Policyholder Contract Deposits By Product [Line Items]
Contractholder funds	9,201,641	10,709,817
Other investment contracts
Policyholder Contract Deposits By Product [Line Items]
Contractholder funds	$ 239,793	$ 222,915