Condensed Consolidated Statements of Earnings (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Premiums and other revenues:
Universal life and annuity contract charges	$ 38,217	$ 40,363	$ 76,222	$ 78,262
Traditional life premiums	5,169	5,218	9,440	9,082
Net investment income	155,179	129,687	263,630	310,501
Other revenues	5,211	5,990	10,974	12,132
Net realized investment gains (losses):
Total other-than-temporary impairment (“OTTI”) gains (losses)	0	(72)	(32)	310
Portion of OTTI (gains) losses recognized in other comprehensive income	0	(106)	(3)	(549)
Net OTTI losses recognized in earnings	0	(178)	(35)	(239)
Other net investment gains (losses)	3,065	1,779	4,613	4,153
Total net realized investment gains (losses)	3,065	1,601	4,578	3,914
Total condensed consolidated premiums and other revenues	206,841	182,859	364,844	413,891
Benefits and expenses:
Life and other policy benefits	14,796	18,450	27,759	31,140
Amortization of deferred policy acquisition costs	27,258	28,852	55,837	59,656
Universal life and annuity contract interest	102,429	71,438	165,365	211,738
Other operating expenses	19,500	24,843	42,963	46,767
Total benefits and expenses	163,983	143,583	291,924	349,301
Earnings before Federal income taxes	42,858	39,276	72,920	64,590
Federal income taxes	13,675	12,285	23,911	20,967
Net earnings	29,183	26,991	49,009	43,623
Common Class A [Member]
Benefits and expenses:
Net earnings	28,358	26,227	47,623	42,389
Basic earnings per share:
Earnings Per Share, Basic (in dollars per share)	$ 8.26	$ 7.64	$ 13.86	$ 12.34
Diluted earnings per share:
Earnings Per Share, Diluted (in dollars per share)	$ 8.25	$ 7.62	$ 13.86	$ 12.32
Common Class B [Member]
Benefits and expenses:
Net earnings	$ 825	$ 764	$ 1,386	$ 1,234
Basic earnings per share:
Earnings Per Share, Basic (in dollars per share)	$ 4.13	$ 3.82	$ 6.93	$ 6.17
Diluted earnings per share:
Earnings Per Share, Diluted (in dollars per share)	$ 4.13	$ 3.82	$ 6.93	$ 6.17