Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash provided from (used for) operating activities:
Net income		$ 549,779	$ 527,100	$ 542,939
Adjustments to reconcile net income from continuing operations to cash provided from continuing operations:
(Income) from discontinued operations, net of income taxes		(10,189)	(10,807)	(14,865)
Increase in future policy benefits		645,844	631,202	585,632
Increase (decrease) in other policy benefits		24,668	14,609	12,521
Deferral of policy acquisition costs		(635,318)	(612,181)	(562,245)
Amortization of deferred policy acquisition costs		469,063	445,625	415,914
Change in current and deferred income taxes	[1]	152,210	103,558	102,720
Realized (gains) losses on sale of investments and properties		10,683	8,791	(23,548)
Other, net		20,079	13,985	(38,354)
Net cash provided from (used for) continuing operations		1,226,819	1,121,882	1,020,714
Net cash provided from (used for) discontinued operations		171,889	(1,832)	(156,006)
Cash provided from (used for) operating activities		1,398,708	1,120,050	864,708
Cash provided from (used for) investing activities:
Fixed maturities available for sale—sold		340,434	226,792	109,024
Fixed maturities available for sale—matured, called, and repaid		236,353	376,158	273,223
Other long-term investments		1,217	3,740	1,495
Total investments sold or matured		578,004	606,690	383,742
Acquisition of investments:
Fixed maturities—available for sale		(1,530,053)	(1,070,908)	(704,993)
Other long-term investments		(20,444)	(31,707)	0
Total investments acquired		(1,550,497)	(1,102,615)	(704,993)
Net increase in policy loans		(15,513)	(20,353)	(23,222)
Net (increase) decrease in short-term investments		(17,274)	(38,884)	61,008
Additions to properties		(25,162)	(36,957)	(19,367)
Sales of properties		90	0	8,752
Investments in low-income housing interests		(32,084)	(41,231)	(56,083)
Cash provided from (used for) investing activities		(1,062,436)	(633,350)	(350,163)
Cash provided from (used for) financing activities:
Issuance of common stock		61,329	35,958	56,294
Cash dividends paid to shareholders		(66,931)	(66,899)	(65,006)
Repayment of debt		(250,000)	0	0
Proceeds from issuance of debt		400,000	0	0
Payment for debt issuance costs		(9,638)	0	0
Net borrowing (repayment) of commercial paper		22,224	1,978	9,328
Excess tax benefit from stock option exercises	[1]	0	17,577	18,524
Acquisition of treasury stock		(404,784)	(418,526)	(449,308)
Net receipts (payments) from deposit-type product		(71,991)	(95,793)	(69,792)
Cash provided from (used for) financing activities		(319,791)	(525,705)	(499,960)
Effect of foreign exchange rate changes on cash		(1,701)	34,369	14,491
Increase (decrease) in cash		14,780	(4,636)	29,076
Cash at beginning of year		61,383	66,019	36,943
Cash at end of year		$ 76,163	$ 61,383	$ 66,019

[1] Certain current year amounts were prospectively adjusted to give effect to the adoption of ASU 2016-09 related to excess tax benefits from stock compensation as described in Note 1—Significant Accounting Policies under "Accounting Pronouncements Adopted in the Current Year."