AVAILABLE-FOR-SALE INVESTMENT SECURITIES (Details 2) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Schedule of Available-for-sale Investment Securities
Proceeds from sales		$ 292,561	$ 21,611	$ 473,062	$ 351,842
Gross realized gains		5,554	671	9,958	4,216
Gross realized losses	[1]				127
Related tax expense		$ 2,333	$ 282	$ 4,182	1,717
MetroCorp
Schedule of Available-for-sale Investment Securities
Gross realized losses					$ 127

[1] The gross $127 thousand of losses resulted from the available-for-sale investment securities acquired from MetroCorp which were sold immediately after the acquisition closed.