Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016		Mar. 31, 2015
Cash provided from operations	$ 337,748	[1]	$ 279,729
Investments sold or matured:
Fixed maturities available for sale—sold	14,331	[1]	11,444
Fixed maturities available for sale—matured, called, and repaid	44,622	[1]	127,554
Other long-term investments	8	[1]	51
Total long-term investments sold or matured	58,961	[1]	139,049
Acquisition of investments:
Fixed maturities—available for sale	(287,204)	[1]	(291,798)
Other long-term investments	(644)	[1]	(19)
Total investments acquired	(287,848)	[1]	(291,817)
Net increase in policy loans	(4,378)	[1]	(2,608)
Net (increase) decrease in short-term investments	(89,905)	[1]	(76,006)
Net change in payable or receivable for securities	2,990	[1]	0
Additions to property and equipment	(3,879)	[1]	(6,080)
Investment in low-income housing interests	(7,925)	[1]	(6,865)
Cash from (used for) investment activities	(331,984)	[1]	(244,327)
Cash provided from (used for) financing activities:
Issuance of common stock	3,763	[1]	11,823
Cash dividends paid to shareholders	(16,524)	[1]	(16,210)
Net borrowing (repayment) of commercial paper	66,899	[1]	20,523
Excess tax benefit from stock option exercises	0	[1]	4,952
Acquisition of treasury stock	(85,089)	[1]	(110,619)
Net receipts (payments) from deposit-type product	(17,641)	[1]	(15,558)
Cash provided from (used for) financing activities	(48,592)	[1]	(105,089)
Effect of foreign exchange rate changes on cash	(5,797)	[1]	6,754
Net increase (decrease) in cash	(48,625)	[1]	(62,933)
Cash at beginning of year	61,383	[1]	66,019
Cash at end of period	12,758	[1]	$ 3,086
New Accounting Pronouncement, Early Adoption, Effect [Member]
Cash provided from (used for) financing activities:
Excess tax benefit from stock option exercises	$ 2,000

[1] Due to the adoption of ASU 2016-09, the excess tax benefits from stock option exercises of $2 million for the quarter ended March 31, 2016 were presented as a component of operating activities in the same manner as other cash flows related to income taxes. See further discussion at Note 2—New Accounting Standards.