SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2014 entity	Dec. 31, 2015 location trust banking_branch representative_office
Operations summary
Number of banking locations | location		130
Principles of Consolidation
Number of wholly owned subsidiaries that are statutory business trusts ("the Trusts") | trust		6
Loans held-for-investments, net
Number of past due days for the loans receivable to be placed on nonaccrual status		90 days
MetroCorp
Principles of Consolidation
Number of acquisitions | entity	1
Greater China
Operations summary
Number of full-service branches		5
Number of representative offices | representative_office		5
Shanghai
Operations summary
Number of full-service branches		2
Shanghai Pilot Free Trade Zone
Operations summary
Number of full-service branches		1