CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities:
Net income	$ 605,293	$ 511,294
Change in operating assets and liabilities:
Accrued investment income	(63,321)	(58,863)
Premiums receivable and other reinsurance balances	(421,027)	(3,619)
Deferred policy acquisition costs	67,471	(15,059)
Reinsurance ceded receivable balances	(120,013)	(77,741)
Future policy benefits, other policy claims and benefits, and other reinsurance balances	982,164	479,606
Deferred income taxes	236,185	165,988
Other assets and other liabilities, net	78,848	29,343
Amortization of net investment premiums, discounts and other	(95,227)	(55,967)
Depreciation, Depletion and Amortization	21,384	19,489
Investment related (gains) losses, net	(139,471)	(84,002)
Other, net	(47,787)	109,403
Net cash provided by operating activities	1,104,499	1,019,872
Cash Flows from Investing Activities:
Sales of fixed maturity securities available-for-sale	6,364,236	3,649,187
Maturities of fixed maturity securities available-for-sale	385,993	349,836
Proceeds from Sale of Available-for-sale Securities, Equity	192,821	331,978
Payments to Acquire Available-for-sale Securities, Debt	7,450,749	5,938,302
Payments to Acquire Available-for-sale Securities, Equity	(60,790)	(523,499)
Payments to Acquire Mortgage Notes Receivable	(751,702)	(857,445)
Proceeds from Sale and Collection of Mortgage Notes Receivable	208,052	377,671
Proceeds from Collection of Policy Loans	93,286	59,518
Payments for (Proceeds from) Policy Loans	5,830	5,685
Increase (Decrease) in Funds Held under Reinsurance Agreements	12,597	31,222
Payments to Acquire Property, Plant, and Equipment	(33,242)	0
Change in short-term investments	65,664	418,625
Change in other invested assets	(51,476)	(78,068)
Net cash used in investing activities	(1,056,334)	(2,247,406)
Cash Flows from Financing Activities:
Dividends to stockholders	(85,086)	(74,034)
Proceeds from (Repayments of) Secured Debt	(56,637)	(60,971)
Proceeds from Issuance of Long-term Debt	0	799,984
Payments of Debt Issuance Costs	0	(9,026)
Repayments of Long-term Debt	(301,927)	(1,850)
Purchases of treasury stock	(41,360)	(121,896)
Exercise of stock options, net	4,450	11,752
Change in cash collateral for derivative positions and other arrangements	(46,206)	24,749
Deposits on universal life and other investment type policies and contracts	1,007,563	874,708
Withdrawals on universal life and other investment type policies and contracts	(568,789)	(386,900)
Net cash provided by financing activities	(87,992)	1,056,516
Effect of exchange rate changes on cash	43,699	25,436
Change in cash and cash equivalents	3,872	(145,582)
Cash and cash equivalents, beginning of period	1,200,718	1,525,275
Cash and cash equivalents, end of period	1,204,590	1,379,693
Supplemental disclosures of cash flow information:
Interest Paid, Net	129,136	114,043
Income Taxes Paid, Net	27,385	47,312
Transfer to Investments	$ 2,247,136	$ 3,621