Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Investments:
Securities held to maturity, at amortized cost (fair value: $6,082,330 and $5,259,332)	$ 5,641,909	$ 4,977,516
Securities available for sale, at fair value (amortized cost: $2,422,650 and $2,221,579)	2,624,953	2,390,107
Mortgage loans, net of allowance for possible losses ($4,571 and $3,962)	157,460	141,247
Policy loans	74,967	78,448
Derivatives, index options	30,844	80,284
Other long-term investments	34,472	29,569
Total Investments	8,564,605	7,697,171
Cash and short-term investments	119,290	80,332
Deferred policy acquisition costs	722,542	691,939
Deferred sales inducements	155,753	143,844
Accrued investment income	87,875	79,720
Federal income tax receivable	0	427
Other assets	77,934	80,515
Total assets	9,727,999	8,773,948
Future policy benefits:
Universal life and annuity contracts	8,023,798	7,108,599
Traditional life and annuity contracts	139,657	139,182
Other policyholder liabilities	151,308	151,526
Deferred Federal income tax liability	46,481	57,857
Federal income tax payable	5,962	0
Other liabilities	84,008	97,993
Total liabilities	8,451,214	7,555,157
COMMITMENTS AND CONTINGENCIES (Notes 4, 7, and 9)
Common stock:
Additional paid-in capital	37,767	37,140
Accumulated other comprehensive income	53,176	50,408
Retained earnings	1,182,207	1,127,614
Total stockholders’ equity	1,276,785	1,218,791
Total liabilities and stockholders' equity	9,727,999	8,773,948
Common Class A [Member]
Common stock:
Common stock, value outstanding	3,435	3,429
Common Class B [Member]
Common stock:
Common stock, value outstanding	$ 200	$ 200