Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Investments:
Securities held to maturity, at amortized cost (fair value: $6,588,874 and $6,503,627)	$ 6,078,141		$ 5,962,120
Securities available for sale, at fair value (cost: $2,656,308 and $2,658,512)	2,904,202		2,826,001
Mortgage loans, net of allowance for possible losses ($650 and $650)	125,539	[1]	142,170	[1]
Policy loans	71,143		71,549
Derivatives, index options	130,967		57,890
Other long-term investments	39,136		41,439
Total investments	9,349,128		9,101,169
Cash and short-term investments	86,816		124,561
Deferred policy acquisition costs	709,329		705,397
Deferred sales inducements	154,673		152,844
Accrued investment income	96,355		92,665
Federal income tax receivable	0		5,655
Other assets	80,200		81,567
Total assets	10,476,501		10,263,858
Future policy benefits:
Universal life and annuity contracts	8,587,555		8,430,545
Traditional life reserves	137,826		138,309
Other policyholder liabilities	155,482		148,561
Deferred Federal income tax liability	36,556		55,054
Federal income tax payable	19,861		0
Other liabilities	132,283		99,709
Total liabilities	9,069,563		8,872,178
COMMITMENTS AND CONTINGENCIES (Note 8)
Common stock:
Additional paid-in capital	37,767		37,767
Accumulated other comprehensive income	75,412		76,786
Retained earnings	1,290,124		1,273,492
Total stockholders’ equity	1,406,938		1,391,680
Total liabilities and stockholders' equity	10,476,501		10,263,858
Common Class A [Member]
Common stock:
Common stock, value outstanding	3,435		3,435
Common Class B [Member]
Common stock:
Common stock, value outstanding	$ 200		$ 200

[1] Loan-to-Value Ratio using the most recent appraised value.