COMMITMENTS AND CONTINGENT LIABILITIES - Additional Information (Detail) ¥ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2015 USD ($) agreements	Dec. 31, 2015 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 program commitment | $	$ 182
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	5 years	5 years
Outsourcing agreements, aggregate remaining cost	$ 298	¥ 36,000
Technology and consulting company application maintenance and development services
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	2 years	2 years
Outsourcing agreements, aggregate remaining cost	$ 20	¥ 2,400
Management consulting and technology services company application maintenance and development services
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	2 years	2 years
Outsourcing agreements, aggregate remaining cost	$ 26	¥ 3,100
Information technology and data services company application maintenance and development services first agreement
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	1 year	1 year
Outsourcing agreements, aggregate remaining cost	$ 5	¥ 637
Information technology and data services company application maintenance and development services second agreement
Commitments and Contingencies Disclosure [Line Items]
Outsourcing agreements, remaining term	2 years	2 years
Outsourcing agreements, aggregate remaining cost	$ 13	¥ 1,600