FEDERAL INCOME TAX (Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Computed expected income tax expense	$ 26,762	$ 35,666	$ 16,126
Tax-exempt municipal bond interest income	(7,417)	(7,732)	(8,027)
Nontaxable dividend income	(1,232)	(1,053)	(1,004)
Valuation allowance reduction	(548)	(548)	(547)
Acquisition related expenses	0	0	42
Other, net	(239)	(571)	(728)
Federal income tax expense	$ 17,326us-gaap_IncomeTaxExpenseBenefit	$ 25,762us-gaap_IncomeTaxExpenseBenefit	$ 5,862us-gaap_IncomeTaxExpenseBenefit

Income Tax Reconciliation, Tax Exempt Income, Dividend

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Income Tax Reconciliation, Tax Exempt Income, Interest

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax exempt income, equity in earnings (loss) of an unconsolidated subsidiary, minority noncontrolling interest income (loss), tax holiday, disposition of a business, disposition of an asset, repatriation of foreign earnings, repatriation of foreign earnings jobs creation act of 2004, increase (decrease) in enacted tax rate, prior year income taxes, increase (decrease) in deferred tax asset valuation allowance, and other adjustments.

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