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	155,892	126,943
Other revenue	7,355
Net investment income	290,402	303,129
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	22,351	12,134
Total realized investment gains (losses), net	21,497	11,880
Total revenues	653,467	570,039
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	167,422	139,758
Amortization of deferred acquisition costs and value of business acquired	16,097	15,442
Interest expense	9,339	9,339
Total benefits and expenses, net	537,484	494,686
Income before income taxes	115,983	75,353
Income tax expense	41,755	24,360
Net income	$ 74,228	$ 50,993