FEDERAL INCOME TAX (Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation Of Consolidated Federal Income Tax Expense (Benefit) [Line Items]
Consolidated federal income tax expense (benefit)	$ (11,405)	$ (29,220)	$ 8,379
Consolidated federal income tax expense (benefit), gain on sale of discontinued operations	7,544	0	0
Consolidated federal income tax expense (benefit), discontinued operations	563	4,490	384
Continuing and Discontinuing Operations
Reconciliation Of Consolidated Federal Income Tax Expense (Benefit) [Line Items]
Computed expected income tax expense	5,114	9,202	20,533
Impact of enactment of Tax Act	0	(21,884)	0
Tax-exempt municipal bond interest income	(4,235)	(8,875)	(8,330)
Nontaxable dividend income	(591)	(1,540)	(1,317)
Valuation allowance reduction	(329)	(547)	(547)
Other, net	(3,257)	(1,086)	(1,576)
Consolidated federal income tax expense (benefit)	$ (3,298)	$ (24,730)	$ 8,763