GOODWILL AND OTHER INTANGIBLES - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Jun. 30, 2012
Finite Lived Intangible Assets [Line Items]
Goodwill	$ 28,100		$ 28,100		$ 28,100
Purchase credit card relationship intangible amount						$ 24,500
Amortization expense			3,817	$ 3,723
Business Combination Finite Lived Intangible Assets Net	5,300		5,300
Purchased Credit Card Relationship Intangible [Member]
Finite Lived Intangible Assets [Line Items]
Purchase credit card relationship intangible amount	$ 24,465		24,465		$ 24,465
Amortization period of purchased credit card relationship intangible	6 years 1 month 6 days				6 years 10 months 24 days
Amortization expense	$ 800	$ 800	2,300	2,600
Core Deposits [Member]
Finite Lived Intangible Assets [Line Items]
Purchase credit card relationship intangible amount	$ 45,844		45,844		$ 45,844
Amortization period of purchased credit card relationship intangible	9 years 3 months 18 days				8 years 4 months 24 days
Amortization expense	$ 600	$ 400	$ 1,500	$ 1,200