Consolidated Statements Of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013
Statement Of Cash Flows [Abstract]
Cash provided from operations	$ 419,383		$ 492,620
Long-term investments sold or matured:
Fixed maturities available for sale-sold	28,194		75,096
Fixed maturities available for sale-matured, called, and repaid	107,394		369,962
Equities	700		14,000
Other long-term investments	23		266
Total long-term investments sold or matured	136,311		459,324
Long-term investments acquired:
Fixed maturities	(325,574)		(691,955)
Other long-term investments	0		(550)
Total long-term investments acquired	(325,574)		(692,505)
Net increase in policy loans	(8,937)		(9,281)
Net (increase) decrease in short-term investments	28,329		(8,152)
Net change in payable or receivable for securities	0		(43,991)
Disposition of properties	19		247
Additions to properties	(10,006)		(2,247)
Investment in low-income housing interests	(22,030)		(19,990)
Cash used for investment activities	(201,888)		(316,595)
Cash provided from (used for) financing activities:
Proceeds from exercise of stock options	35,015		53,383
Net borrowings (repayments) of commercial paper	45,874		29,797
Excess tax benefit from stock option exercises	11,098		9,758
Acquisition of treasury stock	(238,313)		(246,403)
Cash dividends paid to shareholders	(31,980)		(29,916)
Net receipts (withdrawals) from deposit-type products	(33,104)		(13,541)
Cash provided by (used for) financing activities	(211,410)		(196,922)
Effect of foreign exchange rate changes on cash	2,775		4,124
Net increase (decrease) in cash	8,860		(16,773)
Cash at beginning of year	36,943	[1]	61,710
Cash at end of period	$ 45,803		$ 44,937

[1] Derived from audited financial statements