INCOME TAXES - Significant Components of the Provision for Income Taxes ( (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current tax expense:
Federal	$ 5,415	$ 305	$ 0
State	0	0	0
Total current tax expense	5,415	305	0
Deferred tax expense:
Federal	16,653	7,924	432
State	4,053	1,981	2,042
Total deferred tax expense	20,706	9,905	2,474
Income tax expense before change in deferred tax asset valuation allowance	26,121	10,210	2,474
Change in deferred tax asset valuation allowance	(126)	(4,797)	(460)
Income tax expense	$ 25,995	$ 5,413	$ 2,014