Consolidated Statements Comprehensive of Income (Unaudited) (USD $)
In Thousands, except Per Share data, unless otherwise specified
 3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Insurance revenues:        
Premiums, net $ 34,205 $ 30,801 $ 66,909 $ 64,426
Contract charges 25,590 23,752 50,723 49,986
Total insurance revenues 59,795 54,553 117,632 114,412
Investment revenues:        
Net investment income 43,435 44,893 87,644 90,284
Net realized investment gains, excluding impairment losses 1,361 1,893 17,198 2,905
Net impairment losses recognized in earnings:        
Total other-than-temporary impairment losses (188) (238) (456) (507)
Portion of loss recognized in other comprehensive income 42 56 150 114
Net impairment losses recognized in earnings (146) (182) (306) (393)
Total investment revenues 44,650 46,604 104,536 92,796
Other revenues 2,312 2,666 4,497 5,074
Total revenues 106,757 103,823 226,665 212,282
BENEFITS AND EXPENSES        
Policyholder benefits 41,276 38,865 79,746 84,139
Interest credited to policyholder account balances 20,377 20,766 40,935 41,247
Amortization of deferred acquisition costs 5,121 705 13,022 10,289
Operating expenses 27,078 26,498 51,040 52,363
Total benefits and expenses 93,852 86,834 184,743 188,038
Income before income tax expense 12,905 16,989 41,922 24,244
Income tax expense 4,508 5,816 14,084 8,280
NET INCOME 8,397 11,173 27,838 15,964
COMPREHENSIVE INCOME, NET OF TAXES        
Change in net unrealized gains on securities available for sale 15,925 19,802 18,017 19,178
Change in future policy benefits (3,502) (2,926) (4,969) (2,206)
Change in policyholder account balances (143) (83) (218) (77)
Other comprehensive income 12,280 16,793 12,830 16,895
COMPREHENSIVE INCOME $ 20,677 $ 27,966 $ 40,668 $ 32,859
Basic and diluted earnings per share:        
Net income $ 0.78 $ 0.97 $ 2.50 $ 1.39