BUSINESS COMBINATIONS (Details 3) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net income available to common stockholders	$ 20,049	$ 5,086	$ 33,101	$ 16,178
Coastal Bankshares, Inc. [Member]
Net interest income and noninterest income	82,968	66,635	161,766	127,924
Net income	$ 20,049	$ 5,086	$ 33,101	$ 16,178
Income per common share available to common stockholders - basic	$ 0.58	$ 0.15	$ 0.95	$ 0.48
Income per common share available to common stockholders - diluted	$ 0.57	$ 0.15	$ 0.94	$ 0.47
Average number of shares outstanding, basic	34,833	34,734	34,786	33,867
Average number of shares outstanding, diluted	35,153	35,069	35,101	34,202