Condensed Consolidated Statements of Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Premium income	$ 178,321	$ 128,087
Fee income	146,946	126,943
Other revenue	7,355
Net investment income	285,362	297,181
Realized investment gains (losses), net:
Total other-than-temporary impairments	(420)	(254)
Other-than-temporary impairments transferred to other comprehensive income (loss)	(434)
Other realized investment gains, net	15,593	16,941
Total realized investment gains (losses), net	14,739	16,687
Total revenues	632,723	568,898
Benefits and expenses:
Life and other policy benefits	145,592	180,908
Increase (decrease) in future policy benefits	45,272	(631)
Interest paid or credited to contractholders	126,931	127,289
Provision for policyholders' share of earnings on participating business	4,979	1,631
Dividends to policyholders	21,852	20,950
Total benefits	344,626	330,147
General insurance expenses	158,476	139,758
Amortization of deferred acquisition costs and value of business acquired	15,506	15,889
Interest expense	9,339	9,339
Total benefits and expenses, net	527,947	495,133
Income before income taxes	104,776	73,765
Income tax expense	37,941	23,842
Net income	$ 66,835	$ 49,923