AVAILABLE-FOR-SALE INVESTMENT SECURITIES (Details 4) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities
Proceeds from sales	$ 1,669,334	$ 623,689	$ 663,569
Gross realized gains	40,367	10,978	13,904
Gross realized losses	0	127	1,815
Related tax expense	$ 16,954	4,557	$ 5,077
MetroCorp
Schedule of Available-for-sale Securities
Gross realized losses		$ 127