INCOME TAXES - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits
Balance, beginning of period	$ 11,353	$ 9,856	$ 13,138
Additions for tax positions of the current year	0	1,857	2,122
Additions for tax positions of prior years	0	70	1,318
Reductions of tax positions of prior years:
Changes in judgment	(4,219)	(430)	(975)
Settlements during the period	0	0	(5,747)
Lapses of applicable statute of limitations	0	0	0
Balance, end of period	7,134	11,353	9,856
Unrecognized tax benefits with certainty of deductibility but with uncertainty about the timing of deductions	0	700	700
Amount of unrecognized tax benefits that would affect the effective income tax rate if recognized	7,100	10,700	9,200
Accrued interest related to the unrecognized tax benefits included in income tax expense (benefit)	40	(2,400)	(3,100)
Accrued interest associated with unrecognized tax benefits	300	$ (1,100)	$ 2,800
Net refund in future period	6,200
Decrease in unrecognized tax benefits	$ 0