Consolidated Statements Of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Net income		$ 527,100		$ 542,939	[1],[2]	$ 528,472	[1],[2]
Adjustments to reconcile net income from continuing operations to cash provided from continuing operations:
(Income) from discontinued operations, net of income taxes		(10,807)		(14,865)	[1],[2]	(21,267)	[1],[2]
Increase in future policy benefits		631,202		585,632	[2]	578,217	[2]
Increase (decrease) in other policy benefits		14,609		12,521	[2]	(7,151)	[2]
Deferral of policy acquisition costs		(612,181)		(562,245)	[2]	(520,248)	[2]
Amortization of deferred policy acquisition costs		445,625		415,914	[1],[2]	400,869	[1],[2]
Change in current and deferred income taxes		103,558		102,720	[2]	74,989	[2]
Realized (gains) losses on sale of investments and properties		8,791		(23,548)	[2]	(7,990)	[2]
Other, net		13,985		(38,354)	[2]	27,230	[2]
Net cash provided from (used for) continuing operations		1,121,882		1,020,714	[2]	1,053,121	[2]
Net cash provided from (used for) discontinued operations		(1,832)		(156,006)	[2]	66,159	[2]
Cash provided from operations		1,120,050		864,708	[2]	1,119,280	[2]
Cash provided from (used for) investment activities:
Fixed maturities available for sale—sold		226,792		109,024	[2]	133,463	[2]
Fixed maturities available for sale—matured, called, and repaid		376,158		273,223	[2]	493,885	[2]
Equity securities		0		700	[2]	14,000	[2]
Other long-term investments		3,740		795	[2]	1,333	[2]
Total investments sold or matured		606,690		383,742	[2]	642,681	[2]
Acquisition of investments:
Fixed maturities—available for sale		(1,070,908)		(704,993)	[2]	(1,143,840)	[2]
Other long-term investments		(31,707)		0	[2]	(591)	[2]
Total investments acquired		(1,102,615)		(704,993)	[2]	(1,144,431)	[2]
Net increase in policy loans		(20,353)		(23,222)	[2]	(24,837)	[2]
Net (increase) decrease in short-term investments		(38,884)		61,008	[2]	17,970	[2]
Net change in payable or receivable for securities		0		0	[2]	(43,987)	[2]
Additions to properties		(36,957)		(19,367)	[2]	(11,168)	[2]
Sales of properties		0		8,752	[2]	570	[2]
Investments in low-income housing interests		(41,231)		(56,083)	[2]	(51,176)	[2]
Cash provided from (used for) investment activities		(633,350)		(350,163)	[2]	(614,378)	[2]
Cash provided from (used for) financing activities:
Issuance of common stock		35,958		56,294	[2]	97,816	[2]
Cash dividends paid to shareholders		(66,899)		(65,006)	[2]	(60,911)	[2]
Net borrowing (repayment) of commercial paper		1,978		9,328	[2]	3,983	[2]
Excess tax benefit from stock option exercises		17,577		18,524	[2]	21,315	[2]
Acquisition of treasury stock		(418,526)		(449,308)	[2]	(482,264)	[2]
Net receipts (payments) from deposit-type product		(95,793)		(69,792)	[2]	(21,808)	[2]
Cash provided from (used for) financing activities		(525,705)		(499,960)	[2]	(535,919)	[2]
Effect of foreign exchange rate changes on cash		34,369		14,491	[2]	6,250	[2]
Increase (decrease) in cash		(4,636)		29,076	[2]	(24,767)	[2]
Cash at beginning of year	[2]	66,019	[3]	36,943		61,710
Cash at end of year		61,383		66,019	[2],[3]	36,943	[2]
7.375% Notes [Member]
Cash provided from (used for) financing activities:
Repayment of 7.375% Notes		$ 0		$ 0	[2]	$ (94,050)	[2]

[1] Certain balances were adjusted to give effect to discontinued operations and the adoption of new accounting guidance as described in Note 1- Significant Accounting Policies under the caption "Low-Income Housing Tax Credit Interests."

[2] Certain balances were adjusted to give effect to discontinued operations as described in Note 1—Significant Accounting Policies.

[3] Certain balances were adjusted to give effect to discontinued operations as described in Note 1—Significant Accounting Policies.