CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Cash flows from operating activities
Net Income (Loss) Attributable to Parent	$ 701,443	$ 502,166	$ 684,047
Change in operating assets and liabilities:
Accrued investment income	(18,761)	(48,458)	(855)
Premiums receivable and other reinsurance balances	(156,836)	(313,882)	(136,710)
Deferred policy acquisition costs	31,024	(66,633)	101,493
Reinsurance ceded receivable balances	(53,221)	(11,740)	39,345
Future policy benefits, other policy claims and benefits, and other reinsurance balances	810,474	1,867,488	1,625,561
Deferred income taxes	293,777	148,996	170,731
Other assets and other liabilities, net	(98,675)	(55,345)	(17,244)
Amortization of net investment premiums, discounts and other	(93,952)	(77,303)	(102,459)
Depreciation, Depletion and Amortization	26,853	31,103	15,309
Investment related (gains) losses, net	(94,195)	164,750	(186,193)
Excess tax benefits from share-based payment arrangement	(162)	(2,963)	3,011
Other, net	117,949	(49,564)	140,119
Net cash provided by operating activities	1,465,718	2,088,615	2,336,155
Cash flows from investing activities
Sales of fixed maturity securities available-for-sale	4,584,828	5,461,687	4,309,985
Principal payments on mortgage loans on real estate	472,435	439,640	539,789
Proceeds from Sale of Available-for-sale Securities, Equity	434,518	81,319	361,831
Proceeds from Sale and Collection of Mortgage Notes Receivable	442,755	383,828	479,908
Principal payments on policy loans	88,840	21,322	63,785
Payments to Acquire Available-for-sale Securities	(7,414,647)	(5,874,309)	(6,129,956)
Payments to Acquire Available-for-sale Securities, Equity	(584,532)	(95,834)	(72,593)
Purchases of fixed maturity securities available-for-sale	(1,092,876)	(810,092)	(721,836)
Payments to Fund Policy Loans	(47,646)	(52,207)	(103,599)
Cash invested in funds withheld at interest	(32,597)	(339,062)	(86,588)
Purchase of businesses, net of cash acquired of $69,823	0	(145,235)	0
Payments to Acquire Property, Plant, and Equipment	(44,642)	(23,553)	(88,361)
Increase (Decrease) in Payables under Repurchase Agreements	0	(101,203)	101,203
Change in short-term investments	465,628	(470,002)	38,060
Change in other invested assets	(97,790)	91,960	(2,573)
Net cash used in investing activities	(2,825,726)	(1,431,741)	(1,310,945)
Cash flows from financing activities
Dividends to stockholders	(100,371)	(93,381)	(87,256)
Repayment of collateral finance and securitization notes	(64,571)	(19,732)	0
Proceeds from Issuance of Secured Debt	0	164,220	300,000
Proceeds from long-term debt issuance	799,984	0	100,000
Debt issuance costs	(8,766)	(4,748)	(4,260)
Principal payments of long-term debt	(2,479)	(2,380)	(772)
Purchases of treasury stock	(122,916)	(384,519)	(201,525)
Excess tax benefits from share-based payment arrangement	162	2,963	(3,011)
Exercise of stock options, net	15,321	11,151	9,246
Change in cash collateral for derivative positions and other arrangements	26,413	52,381	162,435
Deposits on universal life and other investment type policies and contracts	1,041,623	277,280	150,922
Withdrawals on universal life and other investment type policies and contracts	(529,011)	(711,517)	(681,338)
Net cash used in financing activities	1,055,389	(708,282)	(255,559)
Effect of exchange rate changes on cash	(19,938)	(68,986)	(47,629)
Change in cash and cash equivalents	(324,557)	(120,394)	722,022
Cash and cash equivalents, beginning of period	1,525,275	1,645,669	923,647
Cash and cash equivalents, end of period	1,200,718	1,525,275	1,645,669
Supplementary information:
Interest paid	156,727	148,124	136,499
Income taxes paid, net of refunds	61,085	41,577	70,342
Transfer to Investments	120,500	2,092,558	2,001,439
Capital Expenditures Incurred but Not yet Paid	0	253	24,458
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	0	3,894,940	0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	$ 0	$ 4,040,175	$ 0