Summary Of Profitability By Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011		Jun. 30, 2012	Jun. 30, 2011
Segment Reporting Information [Line Items]
Pretax operating income				$ 379,478	$ 368,095	[1]
Applicable taxes				(124,209)	(121,919)	[1]
Total				255,269	246,176	[1]
Realized gains (losses)-Investments				6,284	5,557	[1]
Loss on disposal of discontinued operations	0	0	[2]	0	(599)	[1],[2]
Part D adjustment				(13,888)	(3,676)	[1]
Estimated state administrative settlement				0	(3,900)	[1]
Loss on sale of equipment				0	(636)	[1]
Net income	128,988	142,781	[2]	247,665	242,922	[1],[2]
Pretax operating income, Increase (Decrease)				11,383
Applicable taxes				(2,290)
Total				9,093
Realized gains (losses)-Investments				727
Loss on disposal of discontinued operations				599
Part D adjustment				(10,212)
Estimated state administrative settlement				3,900
Loss on sale of equipment				636
Net income				4,743
Pretax operating income, Increase (Decrease) %				3.00%
Applicable taxes				2.00%
Total				4.00%
Net income				2.00%
Life Insurance
Segment Reporting Information [Line Items]
Pretax operating income				250,295	228,142	[1]
Pretax operating income, Increase (Decrease)				22,153
Pretax operating income, Increase (Decrease) %				10.00%
Health Insurance
Segment Reporting Information [Line Items]
Pretax operating income				96,214	95,997	[1]
Pretax operating income, Increase (Decrease)				217
Annuity
Segment Reporting Information [Line Items]
Pretax operating income				1,772	1,166	[1]
Pretax operating income, Increase (Decrease)				606
Investment
Segment Reporting Information [Line Items]
Pretax operating income				126,206	131,272	[1]
Pretax operating income, Increase (Decrease)				(5,066)
Pretax operating income, Increase (Decrease) %				(4.00%)
Other Income
Segment Reporting Information [Line Items]
Pretax operating income				865	1,240	[1]
Pretax operating income, Increase (Decrease)				(375)
Pretax operating income, Increase (Decrease) %				(30.00%)
Administrative Expense
Segment Reporting Information [Line Items]
Pretax operating income				(80,427)	(77,909)	[1]
Pretax operating income, Increase (Decrease)				(2,518)
Pretax operating income, Increase (Decrease) %				3.00%
Corporate And Adjustments
Segment Reporting Information [Line Items]
Pretax operating income				(15,447)	(11,813)	[1]
Pretax operating income, Increase (Decrease)				$ (3,634)
Pretax operating income, Increase (Decrease) %				31.00%

[1] The 2011 balances have been retroactively adjusted to give effect to the adoption of new accounting guidance as described in Note F-Adoption of New Accounting Standard.

[2] The 2011 balances have been retrospectively adjusted to give effect to the adoption of new accounting guidance as described in Note F-Adoption of New Accounting Standard.