CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fixed Maturity Securities [Abstract]
Available-for-sale at fair value (amortized cost of $38,882,168 and $35,281,412)	$ 39,992,346	$ 38,150,820
Equity Securities, FV-NI	82,197	100,152
Mortgage loans on real estate (net of allowances of $11,286 and $9,384)	4,966,298	4,400,533
Policy loans	1,344,980	1,357,624
Funds withheld at interest	5,761,471	6,083,388
Short-term investments	142,598	93,304
Other invested assets	1,915,297	1,505,332
Total investments	54,205,187	51,691,153
Cash and cash equivalents	1,889,733	1,303,524
Accrued investment income	427,893	392,721
Premiums receivable and other reinsurance balances	3,017,868	2,338,481
Reinsurance ceded receivables	757,572	782,027
Deferred policy acquisition costs	3,397,770	3,239,824
Other assets	839,222	767,088
Total assets	64,535,245	60,514,818
Liabilities and Stockholders’ Equity
Future policy benefits	25,285,400	22,363,241
Interest-sensitive contract liabilities	18,004,526	16,227,642
Other policy claims and benefits	5,642,755	4,992,074
Other reinsurance balances	487,177	488,739
Deferred income taxes	1,798,800	2,198,309
Other liabilities	1,396,200	1,102,975
Long-term debt	2,787,873	2,788,365
Collateral finance and securitization notes	681,961	783,938
Total liabilities	56,084,692	50,945,283
Commitments and contingent liabilities (See Note 12)
Stockholders Equity:
Preferred stock (par value $.01 per share; 10,000,000 shares authorized; no shares issued or outstanding)	0	0
Common stock (par value $.01 per share; 140,000,000 shares authorized; shares issued: 79,137,758 at December 31, 2018 and 2017)	791	791
Additional paid-in-capital	1,898,652	1,870,906
Retained earnings	7,284,949	6,736,265
Treasury stock, at cost - 16,323,390 and 14,685,663 shares	(1,370,602)	(1,102,058)
Accumulated other comprehensive income	636,763	2,063,631
Total stockholders’ equity	8,450,553	9,569,535
Total liabilities and stockholders’ equity	$ 64,535,245	$ 60,514,818