FAIR VALUE OF FINANCIAL INSTRUMENTS (Carrying Value and Estimated Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Investments
Held-to-maturity securities	$ 199	$ 675
Available-for-sale securities	3,168,542	3,061,208
Trading securities	20,034	16,975
Fixed Maturities
Investments
Held-to-maturity securities	199
Available-for-sale securities	2,898,126
Fair Value
Investments
Mortgage loans	3,895	4,237
Policy loans	5,366	5,618
Other long-term investments	67,639	54,151
Short-term investments	175	175
Cash and cash equivalents	110,853	106,449
Corporate-owned life insurance	2,592	1,716
Policy reserves
Annuity (accumulations)	646,764	707,190
Annuity (benefit payments)	144,283	131,899
Fair Value \| Fixed Maturities
Investments
Held-to-maturity securities	199	675
Available-for-sale securities	2,898,126	2,824,961
Trading securities	14,390	12,622
Fair Value \| Equity securities
Investments
Available-for-sale securities	270,416	236,247
Trading securities	5,644	4,353
Carrying Value
Investments
Mortgage loans	3,706	3,961
Policy loans	5,366	5,618
Other long-term investments	67,639	54,151
Short-term investments	175	175
Cash and cash equivalents	110,853	106,449
Corporate-owned life insurance	2,592	1,716
Policy reserves
Annuity (accumulations)	666,711	744,931
Annuity (benefit payments)	95,129	95,467
Carrying Value \| Fixed Maturities
Investments
Held-to-maturity securities	198	672
Available-for-sale securities	2,898,126	2,824,961
Trading securities	14,390	12,622
Carrying Value \| Equity securities
Investments
Available-for-sale securities	270,416	236,247
Trading securities	$ 5,644	$ 4,353

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Fair value portion of the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

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Fair value of investments in debt securities classified as held-to-maturity.

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Fair value portion of mortgage loans held-for-sale.

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Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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