ALLOWANCE FOR CREDIT LOSSES, NONPERFORMING ASSETS, AND CONCENTRATIONS OF CREDIT RISK - Performance Indicators for Nonperforming Assets (Details)	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans and leases as a percentage of total loans and leases	1.19%	1.65%
Nonperforming assets as a percentage of total assets	0.85%	1.20%
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans and leases as a percentage of total loans and leases	0.19%	0.31%
Nonperforming assets as a percentage of total assets	0.13%	0.23%
Retail
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonperforming loans and leases as a percentage of total loans and leases	1.00%	1.34%
Nonperforming assets as a percentage of total assets	0.72%	0.97%