Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net earnings	$ 105,588us-gaap_NetIncomeLoss	$ 96,247us-gaap_NetIncomeLoss	$ 92,558us-gaap_NetIncomeLoss
Adjustments to reconcile net earnings to net cash provided by operating activities:
Universal life and annuity contract interest	298,259	454,594	262,339
Surrender charges and other policy revenues	(12,913)us-gaap_OtherNoncashIncome	(14,622)us-gaap_OtherNoncashIncome	(14,720)us-gaap_OtherNoncashIncome
Realized (gains) losses on investments	(11,605)us-gaap_GainLossOnInvestments	(8,653)us-gaap_GainLossOnInvestments	(13,201)us-gaap_GainLossOnInvestments
Accretion/amortization of discounts and premiums, investments	(653)	(2,019)	(1,458)
Depreciation and amortization	3,421	4,674	5,688
(Increase) decrease in value of derivatives	(68,616)us-gaap_UnrealizedGainLossOnDerivatives	(225,899)us-gaap_UnrealizedGainLossOnDerivatives	(27,147)us-gaap_UnrealizedGainLossOnDerivatives
(Increase) decrease in deferred policy acquisition and sales inducement costs	(18,336)	(26,165)	(10,623)
(Increase) decrease in accrued investment income	(760)	(2,312)	(4,790)
(Increase) decrease in other assets	(867)	(17,343)	(7,176)
Increase (decrease) in liabilities for future policy benefits	7,698	9,664	13,536
(Decrease) increase in other policyholder liabilities	(3,365)	(5,974)	(2,747)
(Decrease) increase in Federal income tax liability	(6,731)	15,722	(10,617)
Increase (decrease) in deferred Federal income tax	22,538	(23,654)	(4,437)
(Decrease) increase in other liabilities	(394)	(660)	13,076
Other, net	0	(1)	0
Net cash provided by operating activities	313,264	253,599	290,281
Proceeds from sales of:
Securities held to maturity	0	1,980	0
Securities available for sale	29,730	10,246	8,214
Other investments	3,399	11,024	8,791
Proceeds from maturities and redemptions of:
Securities held to maturity	445,679	1,231,796	1,473,885
Securities available for sale	330,127	287,858	347,521
Derivatives, index options	203,349	172,112	54,745
Purchases of:
Securities held to maturity	(773,743)	(1,775,153)	(1,787,388)
Securities available for sale	(410,127)	(256,855)	(490,689)
Derivatives, index options	(73,318)	(61,624)	(56,413)
Other investments	(376)	(15)	(5,380)
Principal payments on mortgage loans	20,506	43,856	36,545
Cost of mortgage loans acquired	(37,104)	(34,129)	(21,454)
(Increase) decrease in policy loans	2,324	5,580	3,418
Other, net	0	0	3
Net cash used in investing activities	(259,554)	(363,324)	(428,202)
Cash flows from financing activities:
Dividends on common stock	(1,273)us-gaap_PaymentsOfDividendsCommonStock	(1,273)us-gaap_PaymentsOfDividendsCommonStock	(1,273)us-gaap_PaymentsOfDividendsCommonStock
Deposits to account balances for universal life and annuity contracts	985,003	982,305	985,370
Return of account balances on universal life and annuity contracts	(880,658)	(875,661)	(841,126)
Issuance of common stock under stock option plan	350	0	0
Net cash provided by (used in) financing activities	103,422	105,371	142,971
Effect of foreign exchange	(913)	652	221
Net increase (decrease) in cash and cash equivalents	156,219	(3,702)	5,271
Cash and short-term investments at beginning of period	120,859	124,561	119,290
Cash and short-term investments at end of period	277,078	120,859	124,561
Cash paid during the period for:
Interest	40us-gaap_InterestPaid	50us-gaap_InterestPaid	40us-gaap_InterestPaid
Income taxes	36,123us-gaap_IncomeTaxesPaid	57,350us-gaap_IncomeTaxesPaid	62,540us-gaap_IncomeTaxesPaid
Noncash operating activities:
Deferral of sales inducements	$ (8,003)	$ 803	$ 4,498

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Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes.

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Cash includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the customer may deposit additional funds at any time and effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid Investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Short-term investments, exclusive of cash equivalents, generally consist of marketable securities intended to be sold within one year (or the normal operating cycle if longer) and may include trading securities, available-for-sale securities, or held-to-maturity securities (if maturing within one year), as applicable.

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This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting and losses recognized for other than temporary impairments (OTTI) of the subject investments.

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The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

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