DEFERRED POLICY ACQUISITION COSTS AND INSURANCE EXPENSES - Additional Information (Detail) - USD ($) $ in Billions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Policy Acquisition Costs Disclosures [Abstract]
Capitalization of deferred policy acquisition costs	$ 1.5	$ 1.4	$ 1.3
Commissions deferred as a percentage of total acquisition costs	72.00%	74.00%	74.00%
Personnel, compensation and benefit expenses as a percentage of insurance expenses	56.00%	53.00%	52.00%

Total amount of policy acquisition costs capitalized during the income statement period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35755530&loc=d3e11264-158415

Name:	us-gaap_DeferredPolicyAcquisitionCostsAdditions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration