REGULATORY MATTERS, COMMITMENTS AND CONTINGENCIES - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Capital Conservation Buffer	2.50%
Common Equity Tier 1 Capital Conservation Buffer First Year	0.625%
Common Equity Tier 1 Capital Conservation Buffer	2.50%
Banking Organizations Basel Advanced Approach Asset Requirement	$ 250,000.0
Foreign Subsidiaries Basel Advanced Approach Asset Requirement	10,000.0
Government National Mortgage Association Certificates and Obligations (GNMA) [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Securitization of FHA/VA mortgage loan production into GNMA mortgage-backed securities	$ 233.2	$ 235.1
Minimum [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Common Equity Tier 1 Capital To Risk Weight Assets Ratio	4.50%
Common equity tier 1 capital to risk weight assets ratio plus common equity tier1 capital conservation buffer	7.00%
Total Tier 1 Capital To Risk Weight Assets Ratio	6.00%
Total Tier 1 Capital To Risk Weight Assets Ratio Plus Common Equity Tier 1 Capital Conservation Buffer	8.50%
Total Tier1 Capital And Tier 2 Capital To Risk Weight Assets Ratio	8.00%
Total Tier 1 Capital And Tier 2 Capital To Risk Weight Assets Ratio Plus Common Equity Tier 1 Capital Conservation Buffer	10.50%
Leverage Ratio	4.00%