OTHER COMPREHENSIVE INCOME - Components (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated other comprehensive (loss) income, net of tax
Beginning balance, net of tax	$ (1,510)	$ (1,518)
Other comprehensive (loss) income before reclassification, net of tax	(12,860)	1,178
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(3,836)	302
Other comprehensive (loss), net of income taxes	(9,024)	876
Ending balance, net of tax	(10,534)	(642)
Accumulated Other Comprehensive Income
Accumulated other comprehensive (loss) income, net of tax
Other comprehensive (loss), net of income taxes	(9,024)	876
Unrealized gains (losses) on available for sale securities
Accumulated other comprehensive (loss) income, net of tax
Beginning balance, net of tax	680	680
Other comprehensive (loss) income before reclassification, net of tax	1,073	2,912
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	356	824
Other comprehensive (loss), net of income taxes	717	2,088
Ending balance, net of tax	1,397	2,768
Unrealized gains (losses) on derivatives
Accumulated other comprehensive (loss) income, net of tax
Beginning balance, net of tax	(2,198)	(2,198)
Other comprehensive (loss) income before reclassification, net of tax	(13,933)	(1,734)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(4,192)	(522)
Other comprehensive (loss), net of income taxes	(9,741)	(1,212)
Ending balance, net of tax	(11,939)	$ (3,410)
Retirement benefit plan
Accumulated other comprehensive (loss) income, net of tax
Beginning balance, net of tax	8
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	0
Other comprehensive (loss), net of income taxes	0
Ending balance, net of tax	$ 8