CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash Flows from Operating Activities:
Net income	$ 145,512	$ 76,472
Change in operating assets and liabilities:
Accrued investment income	(10,501)	(24,379)
Premiums receivable and other reinsurance balances	(54,845)	(51,778)
Deferred policy acquisition costs	58,962	(79,468)
Reinsurance ceded receivable balances	(81,046)	(68,918)
Future policy benefits, other policy claims and benefits, and other reinsurance balances	396,459	375,670
Deferred income taxes	50,110	23,406
Other assets and other liabilities, net	(11,101)	(18,513)
Amortization of net investment premiums, discounts and other	(23,471)	(15,782)
Depreciation, Depletion and Amortization	6,845	6,128
Investment related (gains) losses, net	(60,523)	120,886
Other, net	964	24,848
Net cash provided by operating activities	417,365	368,572
Cash Flows from Investing Activities:
Sales of fixed maturity securities available-for-sale	1,563,956	977,314
Maturities of fixed maturity securities available-for-sale	201,515	116,644
Proceeds from Sale of Available-for-sale Securities, Equity	152,509	40,426
Payments to Acquire Mortgage Notes Receivable	(88,835)	(141,228)
Payments to Fund Policy Loans	(24,663)	(16,939)
Payments to Acquire Available-for-sale Securities	1,933,120	1,768,881
Payments to Acquire Available-for-sale Securities, Equity	(14,646)	(20,288)
Proceeds from Sale and Collection of Mortgage Notes Receivable	(184,575)	(305,252)
Increase (Decrease) in Funds Held under Reinsurance Agreements	2,753	4,980
Payments to Acquire Property, Plant, and Equipment	(16,893)	0
Change in short-term investments	23,668	124,653
Change in other invested assets	(14,126)	(27,400)
Net cash used in investing activities	(110,967)	(709,597)
Cash Flows from Financing Activities:
Dividends to stockholders	(26,381)	(24,019)
Proceeds from (Repayments of) Secured Debt	(16,908)	(6,877)
Payments of Debt Issuance Costs	0	0
Repayments of Long-term Debt	(300,636)	(610)
Purchases of treasury stock	(3,067)	(105,803)
Exercise of stock options, net	1,719	3,239
Change in cash collateral for derivative positions and other arrangements	(3,628)	40,392
Deposits on universal life and other investment type policies and contracts	202,850	432,684
Withdrawals on universal life and other investment type policies and contracts	(201,784)	(41,613)
Net cash provided by (used in) financing activities	(347,835)	297,393
Effect of exchange rate changes on cash	18,833	20,439
Change in cash and cash equivalents	(22,604)	(23,193)
Cash and cash equivalents, beginning of period	1,200,718	1,525,275
Cash and cash equivalents, end of period	1,178,114	1,502,082
Supplemental disclosures of cash flow information:
Interest Paid, Net	46,401	29,112
Income Taxes Paid, Net	12,132	12,322
Transfer to Investments	$ 1,653	$ 689