INCOME TAXES - Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal									$ 23,923	$ 23,872	$ 22,612
State									4,913	5,116	4,863
Total current									28,836	28,988	27,475
Deferred:
Federal									2,920	2,220	991
State									586	432	221
Total deferred									3,506	2,652	1,212
Net provision	$ 8,890	$ 8,825	$ 8,540	$ 6,087	$ 9,258	$ 8,831	$ 7,955	$ 5,596	$ 32,342	$ 31,640	$ 28,687