COMMITMENTS AND CONTINGENT LIABILITIES - Additional Information (Detail) ¥ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) agreements	Dec. 31, 2016 JPY (¥)
Commitments and Contingencies Disclosure [Line Items]
Number of operating service agreements, technology and consulting	2
Number of operating service agreements, management consulting and technology	1
Middle Market Loan Commitment | $	$ 779
Commercial mortgage loan commitments | $	$ 19
Number of operating service agreements, information technology and data services	2
Operating Leases, lease terms	expire in various years through 2026	expire in various years through 2026
Mainframe and server computer operations and support
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	4 years	4 years
Outsourcing agreements, aggregate remaining cost	$ 315	¥ 36,700
Technology and consulting company application maintenance and development services
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	5 years	5 years
Outsourcing agreements, aggregate remaining cost	$ 102	¥ 11,900
Management consulting and technology services company application maintenance and development services
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	5 years	5 years
Outsourcing agreements, aggregate remaining cost	$ 132	¥ 15,400
Information technology and data services company application maintenance and development services first agreement
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	3 years	3 years
Outsourcing agreements, aggregate remaining cost	$ 53	¥ 6,100
Information technology and data services company application maintenance and development services second agreement
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	1 year	1 year
Outsourcing agreements, aggregate remaining cost	$ 6	¥ 740