INCOME TAXES (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current expense
Federal									$ 11,946	$ 14,709	$ 9,570
State									5,052	6,350	4,357
Total current expense									16,998	21,059	13,927
Deferred expense (benefit)
Federal									8,466	2,877	1,598
State									1,754	(37)	959
Total deferred expense (benefit)									10,220	2,840	2,557
Total expense	$ 8,268	$ 7,867	$ 7,213	$ 3,869	$ 6,201	$ 6,415	$ 5,934	$ 5,350	$ 27,218	$ 23,899	$ 16,484