Reinsurance Group of America (RGA) 10-Q 1 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Document Information [Line Items]
Amendment Flag	false
Entity Common Stock, Shares Outstanding		62,610,856
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Document Transition Report	false
Entity Incorporation, State or Country Code	MO
Entity Tax Identification Number	43-1627032
Entity File Number	1-11848
Entity Shell Company	false
Document Quarterly Report	true
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Document Period End Date	Sep. 30, 2019
Document Type	10-Q
Entity Central Index Key	0000898174
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Entity Registrant Name	REINSURANCE GROUP OF AMERICA, INCORPORATED

Document and Entity Informati_2

Document and Entity Information Address	9 Months Ended
	Sep. 30, 2019
Entity Addresses [Line Items]
City Area Code	636
Local Phone Number	736-7000
Entity Address, Address Line One	16600 Swingley Ridge Road
Entity Address, City or Town	Chesterfield
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	63017

Document and Entity Informati_3

Document and Entity Information Document and Entity Information Entity Listings - NEW YORK STOCK EXCHANGE, INC. [Member]	9 Months Ended
	Sep. 30, 2019
RGA [Member]
Entity Listings [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01
Trading Symbol	RGA
Security Exchange Name	NYSE
RZA [Member]
Entity Listings [Line Items]
Title of 12(b) Security	6.20% Fixed-To-Floating Rate Subordinated Debentures due 2042
Trading Symbol	RZA
Security Exchange Name	NYSE
RZB [Member]
Entity Listings [Line Items]
Title of 12(b) Security	5.75% Fixed-To-Floating Rate Subordinated Debentures due 2056
Trading Symbol	RZB
Security Exchange Name	NYSE

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets
Fixed maturity securities available-for-sale, at fair value (amortized cost $44,860,441 and $38,882,168)	$ 49,481,267	$ 39,992,346
Equity Securities, FV-NI	134,453	82,197
Mortgage loans on real estate (net of allowances of $11,775 and $11,286)	5,647,265	4,966,298
Policy loans	1,289,868	1,344,980
Funds withheld at interest	5,614,363	5,761,471
Short-term investments	107,503	142,598
Other invested assets	2,215,275	1,915,297
Total investments	64,489,994	54,205,187
Cash and cash equivalents	2,635,596	1,889,733
Accrued investment income	520,301	427,893
Premiums receivable and other reinsurance balances	2,817,709	3,017,868
Reinsurance ceded receivables	863,027	757,572
Deferred policy acquisition costs	3,411,481	3,397,770
Other assets	1,035,877	839,222
Total assets	75,773,985	64,535,245
Liabilities and Stockholders’ Equity
Future policy benefits	27,085,728	25,285,400
Interest-sensitive contract liabilities	22,345,126	18,004,526
Other policy claims and benefits	6,147,432	5,642,755
Other reinsurance balances	512,883	487,177
Deferred income taxes	2,761,726	1,798,800
Other liabilities	1,405,704	1,396,200
Long-term debt	3,381,406	2,787,873
Collateral finance and securitization notes	610,246	681,961
Total liabilities	64,250,251	56,084,692
Commitments and contingent liabilities (See Note 8)
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, 79,137,758 shares issued at September 30, 2019 and December 31, 2018	791	791
Additional paid-in capital	1,927,943	1,898,652
Retained earnings	7,765,678	7,284,949
Treasury stock, at cost - 16,528,557 and 16,323,390 shares	(1,429,024)	(1,370,602)
Accumulated other comprehensive income	3,258,346	636,763
Total stockholders’ equity	11,523,734	8,450,553
Total liabilities and stockholders’ equity	$ 75,773,985	$ 64,535,245

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS PARENTHETICAL - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Available for Sale at Fair value - Amortized cost	$ 44,860,441	$ 38,882,168
Available-for-sale Equity Securities, Amortized Cost Basis	$ 150,384	$ 107,721
Preferred stock par value (per share)	$ 0.01	$ 0.01
Preferred stock shares authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Common stock par value (per share)	$ 0.01	$ 0.01
Common stock shares authorized	140,000,000	140,000,000
Common Stock, Shares, Issued	79,137,758	79,137,758
Common stock shares outstanding	62,609,201	62,814,368
Treasury stock, shares	16,528,557	16,323,390
Allowances for Loan and Lease Losses, Real Estate	$ 11,775	$ 11,286

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Net premiums	$ 2,809,641	$ 2,562,042	$ 8,311,240	$ 7,739,053
Investment income, net of related expenses	678,805	572,742	1,842,760	1,617,132
Investment related gains (losses), net:
Other-than-temporary impairments on fixed maturity securities	(8,539)	(10,705)	(17,992)	(14,055)
Other investment related gains (losses), net	57,323	(9,312)	87,036	(17,004)
Total investment related gains (losses), net	48,784	(20,017)	69,044	(31,059)
Other revenues	90,335	112,764	291,960	272,020
Total revenues	3,627,565	3,227,531	10,515,004	9,597,146
Benefits and Expenses:
Claims and other policy benefits	2,469,981	2,209,920	7,493,516	6,851,614
Interest credited	226,262	143,292	517,293	333,068
Policy acquisition costs and other insurance expenses	321,855	310,639	894,081	987,817
Other operating expenses	209,348	200,262	634,330	586,495
Interest expense	45,927	33,290	129,383	107,769
Collateral finance and securitization expense	7,102	7,467	22,670	22,509
Total benefits and expenses	3,280,475	2,904,870	9,691,273	8,889,272
Income before income taxes	347,090	322,661	823,731	707,874
Provision for income taxes	84,325	21,462	188,761	102,071
Net income	$ 262,765	$ 301,199	$ 634,970	$ 605,803
Earnings per share:
Basic earnings per share	$ 4.19	$ 4.76	$ 10.13	$ 9.47
Diluted earnings per share	$ 4.12	$ 4.68	$ 9.93	$ 9.30

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Comprehensive income (loss)
Net income	$ 262,765	$ 301,199	$ 634,970	$ 605,803
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(34,465)	25,462	11,524	(30,375)
Net unrealized investment gains (losses)	656,656	(215,986)	2,616,390	(1,218,309)
Defined benefit pension and postretirement plan adjustments	(5,958)	931	(6,331)	431
Total other comprehensive income (loss), net of tax	616,233	(189,593)	2,621,583	(1,248,253)
Total comprehensive income (loss)	$ 878,998	$ 111,606	$ 3,256,553	$ (642,450)

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY Statement - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]
Stockholders' Equity Attributable to Parent	$ 9,569,535	$ 791	$ 1,870,906	$ 6,736,265	$ (1,102,058)	$ 2,063,631
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	(2,020)			553		(2,573)
Net income	605,803			605,803
Other Comprehensive Income (Loss), Net of Tax	(1,248,253)
Dividends, Common Stock, Cash	(102,441)			(102,441)
Treasury Stock, Value, Acquired, Cost Method	(273,873)				(273,873)
Stock Issued During Period, Value, Treasury Stock Reissued	(30,572)		(28,238)	(24,654)	(26,988)
Stockholders' Equity Attributable to Parent	8,601,702	791	1,887,336	6,952,170	(1,243,566)	1,004,971
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	0			2,573		(2,573)
Net income	301,199			301,199
Other Comprehensive Income (Loss), Net of Tax	(189,593)
Dividends, Common Stock, Cash	(38,071)			(38,071)
Treasury Stock, Value, Acquired, Cost Method	(108,804)				(108,804)
Stock Issued During Period, Value, Treasury Stock Reissued	(12,890)		(11,808)	(2,345)	(3,427)
Stockholders' Equity Attributable to Parent	8,579,323	791	1,899,144	7,215,526	(1,348,943)	812,805
Stockholders' Equity Attributable to Parent	8,450,553	791	1,898,652	7,284,949	(1,370,602)	636,763
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	(87)			(87)
Net income	634,970			634,970
Other Comprehensive Income (Loss), Net of Tax	2,621,583
Dividends, Common Stock, Cash	(119,233)			(119,233)
Treasury Stock, Value, Acquired, Cost Method	(98,231)				(98,231)
Stock Issued During Period, Value, Treasury Stock Reissued	(34,179)		(29,291)	(34,921)	(39,809)
Stockholders' Equity Attributable to Parent	10,709,011	791	1,920,144	7,549,737	(1,403,774)	2,642,113
Net income	262,765			262,765
Other Comprehensive Income (Loss), Net of Tax	616,233
Dividends, Common Stock, Cash	(43,886)			(43,886)
Treasury Stock, Value, Acquired, Cost Method	(30,487)				(30,487)
Stock Issued During Period, Value, Treasury Stock Reissued	(10,098)		(7,799)	(2,938)	(5,237)
Stockholders' Equity Attributable to Parent	$ 11,523,734	$ 791	$ 1,927,943	$ 7,765,678	$ (1,429,024)	$ 3,258,346

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Stockholders' Equity [Abstract]
Common Stock, Dividends, Per Share, Declared	$ 700	$ 600	$ 1,900	$ 1,600

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows from Operating Activities:
Net income	$ 634,970	$ 605,803
Change in operating assets and liabilities:
Accrued investment income	(40,160)	23,473
Premiums receivable and other reinsurance balances	182,018	(519,107)
Deferred policy acquisition costs	(130,305)	23,682
Reinsurance ceded receivable balances	(124,290)	37,468
Future policy benefits, other policy claims and benefits, and other reinsurance balances	1,174,427	920,492
Deferred income taxes	200,653	(8,136)
Other assets and other liabilities, net	(253,405)	(47,978)
Amortization of net investment premiums, discounts and other	(44,386)	(55,154)
Depreciation, Depletion and Amortization	33,624	32,153
Investment related (gains) losses, net	(69,044)	31,059
Other, net	199,148	56,408
Net cash provided by operating activities	1,763,250	1,100,163
Cash Flows from Investing Activities:
Sales of fixed maturity securities available-for-sale	10,544,915	6,314,968
Maturities of fixed maturity securities available-for-sale	614,489	461,764
Proceeds from Sale of Available-for-sale Securities, Equity	35,840	44,952
Payments to Acquire Debt Securities, Available-for-sale	11,377,473	6,041,665
Payments to Acquire Available-for-sale Securities, Equity	(77,553)	(12,578)
Payments to Acquire Mortgage Notes Receivable	(986,709)	(671,956)
Proceeds from Sale and Collection of Mortgage Notes Receivable	308,694	290,450
Proceeds from Collection of Policy Loans	73,705	43,995
Payments for (Proceeds from) Policy Loans	4,942	6,422
Increase (Decrease) in Funds Held under Reinsurance Agreements	51,623	61,969
Payments to Acquire Businesses, Net of Cash Acquired	3,561	(31,441)
Payments to Acquire Property, Plant, and Equipment	(23,967)	(20,478)
Change in short-term investments	154,332	34,856
Change in other invested assets	(193,475)	(313,464)
Net cash provided by (used in) investing activities	(980,206)	31,012
Cash Flows from Financing Activities:
Dividends to stockholders	(119,233)	(102,441)
Proceeds from (Repayments of) Secured Debt	(76,516)	(75,146)
Payments of Debt Issuance Costs	(4,750)	0
Proceeds from Issuance of Long-term Debt	598,524	0
Repayments of Long-term Debt	(2,091)	(2,007)
Purchases of treasury stock	(98,231)	(273,873)
Exercise of stock options, net	4,259	2,336
Change in cash collateral for derivative positions and other arrangements	(67,069)	(21,288)
Deposits on universal life and other investment type policies and contracts	318,510	320,871
Withdrawals on universal life and other investment type policies and contracts	(572,996)	(520,649)
Net cash used in financing activities	(19,593)	(672,197)
Effect of exchange rate changes on cash	(17,588)	(32,013)
Change in cash and cash equivalents	745,863	426,965
Cash and cash equivalents, beginning of period	1,889,733	1,303,524
Cash and cash equivalents, end of period	2,635,596	1,730,489
Supplemental disclosures of cash flow information:
Interest Paid, Excluding Capitalized Interest, Operating Activities	124,154	124,575
Income Taxes Paid, Net	14,115	99,554
Transfer to Investments	6,198,117	3,763,195
Capital Expenditures Incurred but Not yet Paid	986	0
Noncash or Part Noncash Acquisition, Value of Assets Acquired	8,303	69,853
Noncash or Part Noncash Acquisition, Value of Liabilities Assumed	$ (11,864)	$ (38,412)

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (PARENTHETICAL) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Statement of Cash Flows [Abstract]
Cash Acquired from Acquisition	$ 27,374	$ 4,938

Business and Basis of Presentat

Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	Business and Basis of Presentation Business Reinsurance Group of America, Incorporated (“RGA”) is an insurance holding company that was formed on December 31, 1992. RGA and its subsidiaries (collectively, the “Company”) is engaged in providing traditional reinsurance, which includes individual and group life and health, disability, and critical illness reinsurance. The Company also provides financial solutions, which includes longevity reinsurance, financial reinsurance, stable value products and asset-intensive products, primarily annuities. Basis of Presentation The unaudited condensed consolidated financial statements of the Company have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (“SEC”). Accordingly, these condensed consolidated financial statements do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the Company’s 2018 Annual Report on Form 10-K filed with the SEC on February 27, 2019 (the “2018 Annual Report”). In the opinion of management, all adjustments, including normal recurring adjustments necessary for a fair presentation have been included. Interim results are not necessarily indicative of the results that may be expected for the year ending December 31, 2019. Consolidation

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table sets forth the computation of basic and diluted earnings per share on net income (in thousands, except per share information): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Earnings: Net income (numerator for basic and diluted calculations) $ 262,765 $ 301,199 $ 634,970 $ 605,803 Shares: Weighted average outstanding shares (denominator for basic calculation) 62,666 63,279 62,701 63,941 Equivalent shares from outstanding stock options 1,123 1,017 1,218 1,189 Denominator for diluted calculation 63,789 64,296 63,919 65,130 Earnings per share: Basic $ 4.19 $ 4.76 $ 10.13 $ 9.47 Diluted $ 4.12 $ 4.68 $ 9.93 $ 9.30 The calculation of common equivalent shares does not include the impact of options having a strike or conversion price that exceeds the average stock price for the earnings period, as the result would be antidilutive. The calculation of common equivalent shares also excludes the impact of outstanding performance contingent shares, as the conditions necessary for their issuance have not been satisfied as of the end of the reporting period. The following table presents approximate amounts of stock options and performance contingent shares excluded from the calculation of common equivalent shares (in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Excluded from common equivalent shares: Stock options 139 227 416 349 Performance contingent shares 258 276 182 256

Equity

Equity	9 Months Ended
	Sep. 30, 2019
Stockholders' Equity Note [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	Equity Common Stock The changes in the number of common stock issued, held in treasury and outstanding are as follows for the periods indicated: Issued Held In Treasury Outstanding Balance, December 31, 2018 79,137,758 16,323,390 62,814,368 Common stock acquired — 546,614 (546,614 ) Stock-based compensation (1) — (341,447 ) 341,447 Balance, September 30, 2019 79,137,758 16,528,557 62,609,201 Issued Held In Treasury Outstanding Balance, December 31, 2017 79,137,758 14,685,663 64,452,095 Common stock acquired — 1,750,295 (1,750,295 ) Stock-based compensation (1) — (249,068 ) 249,068 Balance, September 30, 2018 79,137,758 16,186,890 62,950,868 (1) Represents net shares issued from treasury pursuant to the Company’s equity-based compensation programs. Common Stock Held in Treasury Common stock held in treasury is accounted for at average cost. Gains resulting from the reissuance of common stock held in treasury are credited to additional paid-in capital. Losses resulting from the reissuance of common stock held in treasury are charged first to additional paid-in capital to the extent the Company has previously recorded gains on treasury share transactions, then to retained earnings. In January 2019, RGA’s board of directors authorized a repurchase program for up to $400.0 million of RGA’s outstanding common stock. The authorization was effective immediately and does not have an expiration date. Repurchases would be made in accordance with applicable securities laws and would be made through market transactions, block trades, privately negotiated transactions or other means or a combination of these methods, with the timing and number of shares repurchased dependent on a variety of factors, including share price, corporate and regulatory requirements and market and business conditions. Repurchases may be commenced or suspended from time to time without prior notice. In connection with this new authorization, the board of directors terminated the stock repurchase authority granted in 2017. During the first nine months of 2019, RGA repurchased 0.5 million shares of common stock under this program for $79.8 million . During the first nine months of 2018, RGA repurchased 1.8 million shares of common stock under the 2017 repurchase program for $258.5 million . Accumulated Other Comprehensive Income (Loss) The balance of and changes in each component of accumulated other comprehensive income (loss) (“AOCI”) for the nine months ended September 30, 2019 and 2018 are as follows (dollars in thousands): Accumulated Currency Translation Adjustments Unrealized Appreciation (Depreciation) of Investments (1) Pension and Postretirement Benefits Total Balance, December 31, 2018 $ (168,698 ) $ 856,159 $ (50,698 ) $ 636,763 Other comprehensive income (loss) before reclassifications 16,155 3,526,151 (11,735 ) 3,530,571 Amounts reclassified to (from) AOCI — (170,531 ) 3,728 (166,803 ) Deferred income tax benefit (expense) (4,631 ) (739,230 ) 1,676 (742,185 ) Balance, September 30, 2019 $ (157,174 ) $ 3,472,549 $ (57,029 ) $ 3,258,346 Accumulated Currency Translation Adjustments Unrealized Appreciation (Depreciation) of Investments (1) Pension and Postretirement Benefits Total Balance, December 31, 2017 $ (86,350 ) $ 2,200,661 $ (50,680 ) $ 2,063,631 Other comprehensive income (loss) before reclassifications (24,977 ) (1,638,146 ) (3,391 ) (1,666,514 ) Amounts reclassified to (from) AOCI — 79,505 3,986 83,491 Deferred income tax benefit (expense) (5,398 ) 340,332 (164 ) 334,770 Adoption of new accounting standard (2,573 ) — — (2,573 ) Balance, September 30, 2018 $ (119,298 ) $ 982,352 $ (50,249 ) $ 812,805 (1) Includes cash flow hedges of $(47,202) and $8,788 as of September 30, 2019 and December 31, 2018 , respectively, and $29,043 and $2,619 as of September 30, 2018 and December 31, 2017 , respectively. See Note 5 - “Derivative Instruments” for additional information on cash flow hedges. The following table presents the amounts of AOCI reclassifications for the three and nine months ended September 30, 2019 and 2018 (dollars in thousands): Amount Reclassified from AOCI Three months ended September 30, Nine months ended September 30, Details about AOCI Components 2019 2018 2019 2018 Affected Line Item in Statements of Income Net unrealized investment gains (losses): Net unrealized gains (losses) on available-for-sale securities $ 50,537 $ (21,249 ) $ 70,513 $ (60,347 ) Investment related gains (losses), net Cash flow hedges - Interest rate 255 234 1,107 (108 ) (1) Cash flow hedges - Currency/Interest rate (38 ) 50 (19 ) 270 (1) Deferred policy acquisition costs attributed to unrealized gains and losses 21,275 (4,893 ) 98,930 (19,320 ) (2) Total 72,029 (25,858 ) 170,531 (79,505 ) Provision for income taxes (14,808 ) 5,355 (35,087 ) 16,978 Net unrealized gains (losses), net of tax $ 57,221 $ (20,503 ) $ 135,444 $ (62,527 ) Amortization of defined benefit plan items: Prior service cost (credit) $ 267 $ 246 $ 804 $ 739 (3) Actuarial gains/(losses) (1,102 ) (1,866 ) (4,532 ) (4,725 ) (3) Total (835 ) (1,620 ) (3,728 ) (3,986 ) Provision for income taxes 175 340 783 837 Amortization of defined benefit plans, net of tax $ (660 ) $ (1,280 ) $ (2,945 ) $ (3,149 ) Total reclassifications for the period $ 56,561 $ (21,783 ) $ 132,499 $ (65,676 ) (1) See Note 5 - “Derivative Instruments” for additional information on cash flow hedges. (2) This AOCI component is included in the computation of the deferred policy acquisition cost. See Note 8 – “Deferred Policy Acquisition Costs” of the 2018 Annual Report for additional details. (3) This AOCI component is included in the computation of the net periodic pension cost. See Note 10 – “Employee Benefit Plans” for additional details.

Equity Based Compensation

Equity Based Compensation	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Equity Based Compensation	Equity Based Compensation Equity compensation expense was $29.3 million and $28.4 million in the first nine months of 2019 and 2018 , respectively. In the first quarter of 2019, the Company granted 0.2 million stock appreciation rights at $145.25 weighted average exercise price per share and 0.1 million performance contingent units to employees. Additionally, non-employee directors were granted a total of 8,472 shares of common stock. As of September 30, 2019 , 1.4 million share options at a weighted average strike price per share of $76.08 were vested and exercisable, with a remaining weighted average exercise period of 4.1 years. As of September 30, 2019 , the total compensation cost of non-vested awards not yet recognized in the condensed consolidated financial statements was $26.5 million . It is estimated that these costs will vest over a weighted average period of 0.9 years.

Investments

Investments	9 Months Ended
	Sep. 30, 2019
Investments [Abstract]
Investments	Investments Fixed Maturity Securities Available-for-Sale The Company holds various types of fixed maturity securities available-for-sale and classifies them as corporate securities (“Corporate”), Canadian and Canadian provincial government securities (“Canadian government”), residential mortgage-backed securities (“RMBS”), asset-backed securities (“ABS”), commercial mortgage-backed securities (“CMBS”), U.S. government and agencies (“U.S. government”), state and political subdivisions, and other foreign government, supranational and foreign government-sponsored enterprises (“Other foreign government”). The following tables provide information relating to investments in fixed maturity securities by sector as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019: Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value % of Total Other-than- Available-for-sale: Corporate $ 28,154,301 $ 2,277,070 $ 78,152 $ 30,353,219 61.3 % $ — Canadian government 2,962,729 1,670,680 190 4,633,219 9.4 — RMBS 2,360,691 81,367 2,216 2,439,842 4.9 — ABS 2,809,008 27,621 13,994 2,822,635 5.7 275 CMBS 1,698,334 84,345 461 1,782,218 3.6 — U.S. government 1,570,540 98,193 228 1,668,505 3.4 — State and political subdivisions 1,078,019 113,684 1,600 1,190,103 2.4 — Other foreign government 4,226,819 370,109 5,402 4,591,526 9.3 — Total fixed maturity securities $ 44,860,441 $ 4,723,069 $ 102,243 $ 49,481,267 100.0 % $ 275 December 31, 2018: Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value % of Total Other-than- Available-for-sale: Corporate $ 24,006,407 $ 530,804 $ 555,092 $ 23,982,119 59.9 % $ — Canadian government 2,768,466 1,126,227 2,308 3,892,385 9.7 — RMBS 1,872,236 22,267 25,282 1,869,221 4.7 — ABS 2,171,254 10,779 32,829 2,149,204 5.4 275 CMBS 1,428,115 9,153 18,234 1,419,034 3.5 — U.S. government 2,233,537 10,204 57,867 2,185,874 5.5 — State and political subdivisions 721,290 39,914 9,010 752,194 1.9 — Other foreign government 3,680,863 109,320 47,868 3,742,315 9.4 — Total fixed maturity securities $ 38,882,168 $ 1,858,668 $ 748,490 $ 39,992,346 100.0 % $ 275 The Company enters into various collateral arrangements with counterparties that require both the pledging and acceptance of fixed maturity securities as collateral. Pledged fixed maturity securities are included in fixed maturity securities, available-for-sale in the condensed consolidated balance sheets. Fixed maturity securities received as collateral are held in separate custodial accounts and are not recorded on the Company’s condensed consolidated balance sheets. Subject to certain constraints, the Company is permitted by contract to sell or repledge collateral it receives; however, as of September 30, 2019 and December 31, 2018 , none of the collateral received had been sold or repledged. The Company also holds assets in trust to satisfy collateral requirements under derivative transactions and certain third-party reinsurance treaties. The following table includes fixed maturity securities pledged and received as collateral and assets in trust held to satisfy collateral requirements under derivative transactions and certain third-party reinsurance treaties as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Fixed maturity securities pledged as collateral $ 95,387 $ 99,393 $ 80,891 $ 83,950 Fixed maturity securities received as collateral n/a 696,435 n/a 616,584 Assets in trust held to satisfy collateral requirements 26,332,915 28,368,125 20,072,735 20,366,170 The Company monitors its concentrations of financial instruments on an ongoing basis and mitigates credit risk by maintaining a diversified investment portfolio that limits exposure to any one issuer. The Company’s exposure to concentrations of credit risk from single issuers greater than 10% of the Company’s stockholders’ equity included securities of the U.S. government and its agencies as well as the securities disclosed below as of September 30, 2019 and December 31, 2018 (dollars in thousands). September 30, 2019 December 31, 2018 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Fixed maturity securities guaranteed or issued by: Canadian province of Quebec $ 1,167,744 $ 2,153,434 $ 1,091,018 $ 1,757,087 Canadian province of Ontario 981,279 1,371,571 913,642 1,187,526 The amortized cost and estimated fair value of fixed maturity securities classified as available-for-sale at September 30, 2019 are shown by contractual maturity in the table below (dollars in thousands). Actual maturities can differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Asset and mortgage-backed securities are shown separately in the table below, as they are not due at a single maturity date. Amortized Cost Estimated Fair Value Available-for-sale: Due in one year or less $ 1,538,152 $ 1,547,966 Due after one year through five years 8,318,044 8,656,979 Due after five years through ten years 9,485,912 10,275,538 Due after ten years 18,650,300 21,956,089 Asset and mortgage-backed securities 6,868,033 7,044,695 Total $ 44,860,441 $ 49,481,267 Corporate Fixed Maturity Securities The tables below show the major industry types of the Company’s corporate fixed maturity holdings as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019: Estimated Amortized Cost Fair Value % of Total Finance $ 10,604,290 $ 11,327,324 37.3 % Industrial 14,099,496 15,213,256 50.1 Utility 3,450,515 3,812,639 12.6 Total $ 28,154,301 $ 30,353,219 100.0 % December 31, 2018: Estimated Amortized Cost Fair Value % of Total Finance $ 8,793,742 $ 8,730,568 36.3 % Industrial 12,336,857 12,342,111 51.6 Utility 2,875,808 2,909,440 12.1 Total $ 24,006,407 $ 23,982,119 100.0 % Other-Than-Temporary Impairments - Fixed Maturity Securities As discussed in Note 2 – “Significant Accounting Policies and Pronouncements” of the 2018 Annual Report, a portion of certain other-than-temporary impairment (“OTTI”) losses on fixed maturity securities is recognized in AOCI. For these securities, the net amount recognized in the condensed consolidated statements of income (“credit loss impairments”) represents the difference between the amortized cost of the security and the net present value of its projected future cash flows discounted at the effective interest rate implicit in the debt security prior to impairment. Any remaining difference between the fair value and amortized cost is recognized in AOCI. The amount of pre-tax credit loss impairments on fixed maturity securities held by the Company, for which a portion of the OTTI loss was recognized in AOCI, was $3.7 million as of September 30, 2019 and 2018. There were no changes in these amounts from their respective prior-year ending balances . Unrealized Losses for Fixed Maturity Securities Available-for-Sale The following table presents the total gross unrealized losses for the 856 and 3,109 fixed maturity securities as of September 30, 2019 and December 31, 2018, respectively, where the estimated fair value had declined and remained below amortized cost by the indicated amount (dollars in thousands): September 30, 2019 December 31, 2018 Gross Unrealized Losses % of Total Gross Unrealized Losses % of Total Less than 20% $ 75,658 74.0 % $ 721,015 96.3 % 20% or more for less than six months 10,064 9.8 21,336 2.9 20% or more for six months or greater 16,521 16.2 6,139 0.8 Total $ 102,243 100.0 % $ 748,490 100.0 % The Company’s determination of whether a decline in value is other-than-temporary includes an analysis of the underlying credit and the extent and duration of a decline in value. The Company’s credit analysis of an investment includes determining whether the issuer is current on its contractual payments, evaluating whether it is probable that the Company will be able to collect all amounts due according to the contractual terms of the security and analyzing the overall ability of the Company to recover the amortized cost of the investment. The following tables present the estimated fair values and gross unrealized losses, including other-than-temporary impairment losses reported in AOCI, for 856 and 3,109 fixed maturity securities that have estimated fair values below amortized cost as of September 30, 2019 and December 31, 2018, respectively (dollars in thousands). These investments are presented by class and grade of security, as well as the length of time the related fair value has remained below amortized cost. Less than 12 months 12 months or greater Total Gross Gross Gross September 30, 2019: Estimated Unrealized Estimated Unrealized Estimated Unrealized Fair Value Losses Fair Value Losses Fair Value Losses Investment grade securities: Corporate $ 1,570,113 $ 25,598 $ 410,462 $ 11,576 $ 1,980,575 $ 37,174 Canadian government 867 10 17,509 180 18,376 190 RMBS 222,644 987 116,037 1,218 338,681 2,205 ABS 765,223 4,861 413,297 9,133 1,178,520 13,994 CMBS 48,699 218 32,638 232 81,337 450 U.S. government 2,758 7 65,220 221 67,978 228 State and political subdivisions 11,129 97 13,838 1,503 24,967 1,600 Other foreign government 198,170 3,474 45,430 761 243,600 4,235 Total investment grade securities 2,819,603 35,252 1,114,431 24,824 3,934,034 60,076 Below investment grade securities: Corporate 206,108 24,561 122,670 16,417 328,778 40,978 RMBS — — 939 11 939 11 CMBS 1,042 11 — — 1,042 11 Other foreign government 12,914 290 13,173 877 26,087 1,167 Total below investment grade securities 220,064 24,862 136,782 17,305 356,846 42,167 Total fixed maturity securities $ 3,039,667 $ 60,114 $ 1,251,213 $ 42,129 $ 4,290,880 $ 102,243 Less than 12 months 12 months or greater Total Gross Gross Gross December 31, 2018: Estimated Unrealized Estimated Unrealized Estimated Unrealized Fair Value Losses Fair Value Losses Fair Value Losses Investment grade securities: Corporate $ 8,505,371 $ 302,604 $ 3,611,266 $ 195,082 $ 12,116,637 $ 497,686 Canadian government 25,169 419 131,806 1,612 156,975 2,031 RMBS 269,558 2,488 836,741 22,760 1,106,299 25,248 ABS 1,102,677 24,271 381,609 8,523 1,484,286 32,794 CMBS 384,259 4,304 414,719 13,930 798,978 18,234 U.S. government 8,616 80 1,086,694 57,787 1,095,310 57,867 State and political subdivisions 103,504 1,538 157,330 7,472 260,834 9,010 Other foreign government 789,859 24,509 472,934 17,446 1,262,793 41,955 Total investment grade securities 11,189,013 360,213 7,093,099 324,612 18,282,112 684,825 Below investment grade securities: Corporate 755,679 42,760 122,559 14,646 878,238 57,406 Canadian government 443 34 1,770 243 2,213 277 RMBS — — 1,026 34 1,026 34 ABS — — 1,063 35 1,063 35 Other foreign government 128,725 5,574 7,479 339 136,204 5,913 Total below investment grade securities 884,847 48,368 133,897 15,297 1,018,744 63,665 Total fixed maturity securities $ 12,073,860 $ 408,581 $ 7,226,996 $ 339,909 $ 19,300,856 $ 748,490 The Company has no intention to sell, nor does it expect to be required to sell, the securities outlined in the table above, as of the dates indicated. However, unforeseen facts and circumstances may cause the Company to sell fixed maturity securities in the ordinary course of managing its portfolio to meet certain diversification, credit quality and liquidity guidelines. Changes in unrealized losses are primarily driven by changes in interest rates. Investment Income, Net of Related Expenses Major categories of investment income, net of related expenses, consist of the following (dollars in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Fixed maturity securities available-for-sale $ 464,431 $ 378,669 $ 1,307,359 $ 1,121,496 Equity securities 1,709 1,319 3,600 3,710 Mortgage loans on real estate 67,071 54,424 187,142 155,083 Policy loans 14,580 14,730 43,083 44,285 Funds withheld at interest 81,862 108,232 209,568 270,094 Short-term investments and cash and cash equivalents 6,152 3,067 20,517 9,276 Other invested assets 66,611 35,594 140,757 80,207 Investment income 702,416 596,035 1,912,026 1,684,151 Investment expense (23,611 ) (23,293 ) (69,266 ) (67,019 ) Investment income, net of related expenses $ 678,805 $ 572,742 $ 1,842,760 $ 1,617,132 Investment Related Gains (Losses), Net Investment related gains (losses), net, consist of the following (dollars in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Fixed maturity securities available-for-sale: Other-than-temporary impairment losses $ (8,539 ) $ (10,705 ) $ (17,992 ) $ (14,055 ) Gain on investment activity 67,980 20,040 116,409 52,146 Loss on investment activity (12,996 ) (37,880 ) (38,589 ) (94,194 ) Equity securities: Gain on investment activity 432 3,932 506 4,429 Loss on investment activity — (174 ) (1 ) (1,124 ) Change in unrealized gains (losses) recognized in earnings 3,396 3,539 9,813 (7,564 ) Other impairment losses and change in mortgage loan provision (4,030 ) (6,566 ) (11,498 ) (8,235 ) Derivatives and other, net 2,541 7,797 10,396 37,538 Total investment related gains (losses), net $ 48,784 $ (20,017 ) $ 69,044 $ (31,059 ) The fixed maturity impairments for the three months ended September 30, 2019 and 2018 are primarily related to high-yield securities. The fixed maturity impairments for the nine months ended September 30, 2019 were primarily related to a U.S. utility company and high-yield securities. The fixed maturity impairments for the nine months ended September 30, 2018 were primarily related to high-yield securities. The other impairment losses and change in mortgage loan provision for the three months ended September 30, 2019 includes impairments on limited partnerships. The other impairment losses and change in mortgage loan provision for the three months ended September 30, 2018 includes impairments on real estate joint ventures and limited partnerships. The other impairment losses and change in mortgage loan provision for the nine months ended September 30, 2019 and 2018 includes impairments on real estate joint ventures and limited partnerships. The fluctuations in investment related gains (losses) for derivatives and other for the three and nine months ended September 30, 2019 , compared to the same periods in 2018 , are primarily due to changes in the fair value of embedded derivatives and interest rate swaps. During the three months ended September 30, 2019 and 2018 , the Company sold fixed maturity securities with fair values of $1,313.7 million and $1,345.3 million at losses of $13.0 million and $37.9 million , respectively. During the nine months ended September 30, 2019 and 2018 , the Company sold fixed maturity securities with fair values of $3,026.5 million and $3,783.3 million at losses of $38.6 million and $94.2 million , respectively. The Company did not sell any equity securities at losses during the three months ended September 30, 2019 . During the three months ended September 30, 2018, the Company sold equity securities with fair values of $3.1 million at losses of $0.2 million. During the nine months ended September 30, 2019 , the Company sold equity securities for immaterial losses. During the nine months ended September 30, 2018 , the Company sold equity securities with fair values $31.5 million at losses of $1.1 million . The Company generally does not buy and sell securities on a short-term basis. Securities Borrowing, Lending and Other The following table includes the amount of borrowed securities, securities lent and securities collateral received as part of the securities lending program and repurchased/reverse repurchased securities pledged and received as of September 30, 2019 and December 31, 2018 (dollars in thousands). September 30, 2019 December 31, 2018 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Borrowed securities $ 335,408 $ 372,617 $ 335,781 $ 366,663 Securities lending: Securities loaned 97,606 104,191 101,981 102,618 Securities received n/a 107,000 n/a 112,000 Repurchase program/reverse repurchase program: Securities pledged 610,701 644,471 554,806 554,589 Securities received n/a 624,348 n/a 530,932 The Company also held cash collateral for repurchase/reverse repurchase programs of $27.5 million and $28.6 million as of September 30, 2019 and December 31, 2018 , respectively. No cash or securities have been pledged by the Company for its securities borrowing program as of September 30, 2019 and December 31, 2018 . The following tables present information on the Company’s securities lending and repurchase transactions as of September 30, 2019 and December 31, 2018 , respectively (dollars in thousands). Collateral associated with certain borrowed securities is not included within the table, as the collateral pledged to each counterparty is the right to reinsurance treaty cash flows. September 30, 2019 Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days Total Securities lending transactions: Corporate $ — $ — $ — $ 104,191 $ 104,191 Total — — — 104,191 104,191 Repurchase transactions: Corporate — — — 324,033 324,033 U.S. government — — 66,264 142,124 208,388 Foreign government — — — 112,050 112,050 Other — — — — — Total — — 66,264 578,207 644,471 Total borrowings $ — $ — $ 66,264 $ 682,398 $ 748,662 Gross amount of recognized liabilities for securities lending and repurchase transactions in preceding table $ 758,883 Amounts related to agreements not included in offsetting disclosure $ 10,221 December 31, 2018 Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days Total Securities lending transactions: Corporate $ — $ — $ — $ 102,618 $ 102,618 Total $ — $ — $ — $ 102,618 $ 102,618 Repurchase transactions: Corporate $ — $ — $ — $ 254,151 $ 254,151 U.S. government — — — 221,572 221,572 Foreign government — — — 78,866 78,866 Total — — — 554,589 554,589 Total borrowings $ — $ — $ — $ 657,207 $ 657,207 Gross amount of recognized liabilities for securities lending and repurchase transactions in preceding table $ 671,492 Amounts related to agreements not included in offsetting disclosure $ 14,285 The Company has elected to offset amounts recognized as receivables and payables resulting from the repurchase/reverse repurchase programs. After the effect of offsetting, the net amount presented on the condensed consolidated balance sheets was a liability of $0.5 million and $0.4 million as of September 30, 2019 and December 31, 2018 , respectively. As of September 30, 2019 and December 31, 2018 , the Company recognized payables resulting from cash received as collateral associated with a repurchase agreement as discussed above. Amounts owed to and due from the counterparties may be settled in cash or offset, in accordance with the agreements. Mortgage Loans on Real Estate Mortgage loans represented approximately 8.8% and 9.1% of the Company’s total investments as of September 30, 2019 and December 31, 2018 . As of September 30, 2019 , mortgage loans were geographically dispersed throughout the U.S. with the largest concentrations in California ( 17.0% ), Texas ( 12.9% ) and Washington ( 7.4% ). In addition, the Company held mortgage loans secured by properties in Canada ( 2.9% ) and United Kingdom ( 0.5% ). The recorded investment in mortgage loans on real estate presented below is gross of unamortized deferred loan origination fees and expenses, and valuation allowances. The distribution of mortgage loans by property type is as follows as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Property type: Carrying Value % of Total Carrying Value % of Total Office building $ 1,787,871 31.6 % $ 1,725,748 34.6 % Retail 1,645,521 29.0 1,432,394 28.7 Industrial 1,137,598 20.1 961,924 19.3 Apartment 748,392 13.2 571,291 11.5 Other commercial 347,972 6.1 291,997 5.9 Recorded investment 5,667,354 100.0 % 4,983,354 100.0 % Unamortized balance of loan origination fees and expenses (8,314 ) (5,770 ) Valuation allowances (11,775 ) (11,286 ) Total mortgage loans on real estate $ 5,647,265 $ 4,966,298 The maturities of mortgage loans as of September 30, 2019 and December 31, 2018 are as follows (dollars in thousands): September 30, 2019 December 31, 2018 Recorded Investment % of Total Recorded Investment % of Total Due within five years $ 1,750,771 30.9 % $ 1,425,598 28.6 % Due after five years through ten years 3,001,527 53.0 2,686,264 53.9 Due after ten years 915,056 16.1 871,492 17.5 Total $ 5,667,354 100.0 % $ 4,983,354 100.0 % The following tables set forth certain key credit quality indicators of the Company’s recorded investment in mortgage loans as of September 30, 2019 and December 31, 2018 (dollars in thousands): Recorded Investment Debt Service Ratios Construction Loans >1.20x 1.00x - 1.20x <1.00x Total % of Total September 30, 2019: Loan-to-Value Ratio 0% - 59.99% $ 2,912,673 $ 91,954 $ 12,932 $ 21,434 $ 3,038,993 53.6 % 60% - 69.99% 1,889,981 83,814 37,321 — 2,011,116 35.5 70% - 79.99% 395,599 — 32,586 — 428,185 7.6 Greater than 80% 116,605 49,087 23,368 — 189,060 3.3 Total $ 5,314,858 $ 224,855 $ 106,207 $ 21,434 $ 5,667,354 100.0 % Recorded Investment Debt Service Ratios Construction Loans >1.20x 1.00x - 1.20x <1.00x Total % of Total December 31, 2018: Loan-to-Value Ratio 0% - 59.99% $ 2,410,556 $ 61,246 $ 38,177 $ 13,691 $ 2,523,670 50.6 % 60% - 69.99% 1,618,374 73,908 38,120 18,929 1,749,331 35.1 70% - 79.99% 414,269 48,438 54,440 — 517,147 10.4 Greater than 80% 117,978 49,668 25,560 — 193,206 3.9 Total $ 4,561,177 $ 233,260 $ 156,297 $ 32,620 $ 4,983,354 100.0 % The age analysis of the Company’s past due recorded investments in mortgage loans as of September 30, 2019 and December 31, 2018 is as follows (dollars in thousands): September 30, 2019 December 31, 2018 31-60 days past due $ 21,065 $ — Total past due 21,065 — Current 5,646,289 4,983,354 Total $ 5,667,354 $ 4,983,354 The following table presents the recorded investment in mortgage loans, by method of measuring impairment, and the related valuation allowances as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Mortgage loans: Individually measured for impairment $ 17,016 $ 30,635 Collectively measured for impairment 5,650,338 4,952,719 Recorded investment $ 5,667,354 $ 4,983,354 Valuation allowances: Individually measured for impairment $ — $ — Collectively measured for impairment 11,775 11,286 Total valuation allowances $ 11,775 $ 11,286 Information regarding the Company’s loan valuation allowances for mortgage loans for the three and nine months ended September 30, 2019 and 2018 is as follows (dollars in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Balance, beginning of period $ 11,692 $ 9,706 $ 11,286 $ 9,384 Provision (release) 88 656 485 986 Translation adjustment (5 ) 4 4 (4 ) Balance, end of period $ 11,775 $ 10,366 $ 11,775 $ 10,366 Information regarding the portion of the Company’s mortgage loans that were impaired as of September 30, 2019 and December 31, 2018 is as follows (dollars in thousands): Unpaid Principal Balance Recorded Investment Related Allowance Carrying Value September 30, 2019: Impaired mortgage loans with no valuation allowance recorded $ 17,017 $ 17,016 $ — $ 17,016 Impaired mortgage loans with valuation allowance recorded — — — — Total impaired mortgage loans $ 17,017 $ 17,016 $ — $ 17,016 December 31, 2018: Impaired mortgage loans with no valuation allowance recorded $ 30,660 $ 30,635 $ — $ 30,635 Impaired mortgage loans with valuation allowance recorded — — — — Total impaired mortgage loans $ 30,660 $ 30,635 $ — $ 30,635 The Company’s average investment balance of impaired mortgage loans and the related interest income are reflected in the table below for the periods indicated (dollars in thousands): Three months ended September 30, 2019 2018 Average (1) Interest Income Average Recorded Investment (1) Interest Income Impaired mortgage loans with no valuation allowance recorded $ 17,015 $ 170 $ 30,641 $ 346 Impaired mortgage loans with valuation allowance recorded — — — — Total impaired mortgage loans $ 17,015 $ 170 $ 30,641 $ 346 Nine months ended September 30, 2019 2018 Average (1) Interest Income Average (1) Interest Income Impaired mortgage loans with no valuation allowance recorded $ 20,436 $ 669 $ 22,641 $ 650 Impaired mortgage loans with valuation allowance recorded — — — — Total impaired mortgage loans $ 20,436 $ 669 $ 22,641 $ 650 (1) Average recorded investment represents the average loan balances as of the beginning of period and all subsequent quarterly end of period balances. The Company did not acquire any impaired mortgage loans during the nine months ended September 30, 2019 and 2018 . The Company had no mortgage loans that were on a nonaccrual status at September 30, 2019 and December 31, 2018 . Policy Loans Policy loans comprised approximately 2.0% and 2.5% of the Company’s total investments as of September 30, 2019 and December 31, 2018 , respectively, the majority of which are associated with one client. These policy loans present no credit risk because the amount of the loan cannot exceed the obligation due to the ceding company upon the death of the insured or surrender of the underlying policy. The provisions of the treaties in force and the underlying policies determine the policy loan interest rates. The Company earns a spread between the interest rate earned on policy loans and the interest rate credited to corresponding liabilities. Funds Withheld at Interest Funds withheld at interest comprised approximately 8.7% and 10.6% of the Company’s total investments as of September 30, 2019 and December 31, 2018 , respectively. Of the $5.6 billion funds withheld at interest balance, net of embedded derivatives, as of September 30, 2019 , $3.6 billion of the balance is associated with one client. For reinsurance agreements written on a modified coinsurance basis and certain agreements written on a coinsurance funds withheld basis, assets equal to the net statutory reserves are withheld and legally owned and managed by the ceding company and are reflected as funds withheld at interest on the Company’s condensed consolidated balance sheets. In the event of a ceding company’s insolvency, the Company would need to assert a claim on the assets supporting its reserve liabilities. However, the risk of loss to the Company is mitigated by its ability to offset amounts it owes the ceding company for claims or allowances against amounts owed to the Company from the ceding company. Other Invested Assets Other invested assets represented approximately 3.4% and 3.5% of the Company’s total investments as of September 30, 2019 and December 31, 2018 , respectively. Carrying values of these assets as of September 30, 2019 and December 31, 2018 were as follows (dollars in thousands): September 30, 2019 December 31, 2018 Limited partnership interests and real estate joint ventures $ 1,059,025 $ 965,094 Lifetime mortgages 669,981 475,905 Derivatives 142,099 180,699 FVO contractholder-directed unit-linked investments 252,277 197,770 Other 91,893 95,829 Total other invested assets $ 2,215,275 $ 1,915,297

Derivative Instruments

Derivative Instruments	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments Accounting for Derivative Instruments and Hedging Activities See Note 2 – “Significant Accounting Policies and Pronouncements” of the Company’s 2018 Annual Report for a detailed discussion of the accounting treatment for derivative instruments, including embedded derivatives. See Note 6 – “Fair Value of Assets and Liabilities” for additional disclosures related to the fair value hierarchy for derivative instruments, including embedded derivatives. Types of Derivatives Used by the Company Commonly used derivative instruments include, but are not necessarily limited to: credit default swaps, financial futures, equity options, foreign currency swaps, foreign currency forwards, interest rate swaps, synthetic guaranteed investment contracts (“GICs”), consumer price index (“CPI”) swaps, longevity swaps, mortality swaps and embedded derivatives. For detailed information on these derivative instruments and the related strategies, see Note 5 – “Derivative Instruments” of the Company’s 2018 Annual Report. Summary of Derivative Positions Derivatives, except for embedded derivatives and longevity and mortality swaps, are carried on the Company’s condensed consolidated balance sheets in other invested assets or other liabilities, at fair value. Longevity and mortality swaps are included on the condensed consolidated balance sheets in other assets or other liabilities, at fair value. Embedded derivative assets and liabilities on modified coinsurance (“modco”) or funds withheld arrangements are included on the condensed consolidated balance sheets with the host contract in funds withheld at interest, at fair value. Embedded derivative liabilities on indexed annuity and variable annuity products are included on the condensed consolidated balance sheets with the host contract in interest-sensitive contract liabilities, at fair value. The following table presents the notional amounts and gross fair value of derivative instruments prior to taking into account the netting effects of master netting agreements as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Primary Underlying Risk Notional Carrying Value/Fair Value Notional Carrying Value/Fair Value Amount Assets Liabilities Amount Assets Liabilities Derivatives not designated as hedging instruments: Interest rate swaps Interest rate $ 929,963 $ 84,306 $ 2,778 $ 1,040,588 $ 47,652 $ 961 Financial futures Equity 361,030 — — 325,620 — — Foreign currency swaps Foreign currency 149,698 — 12,454 149,698 504 4,659 Foreign currency forwards Foreign currency 125,000 337 — 25,000 — 234 Consumer price index swaps CPI 422,068 360 33,245 385,580 — 11,384 Credit default swaps Credit 1,337,800 5,888 139 1,338,300 6,003 1,166 Equity options Equity 386,536 24,844 — 439,158 42,836 — Longevity swaps Longevity 871,920 51,620 — 917,360 47,789 — Mortality swaps Mortality 25,000 — 853 25,000 — 369 Synthetic guaranteed investment contracts Interest rate 13,919,866 — — 13,397,729 — — Embedded derivatives in: Modified coinsurance or funds withheld arrangements — 121,275 — — 109,597 — Indexed annuity products — — 779,128 — — 776,940 Variable annuity products — — 210,041 — — 167,925 Total non-hedging derivatives 18,528,881 288,630 1,038,638 18,044,033 254,381 963,638 Derivatives designated as hedging instruments: Interest rate swaps Foreign currency/Interest rate 435,000 — 34,467 435,000 — 27,257 Foreign currency swaps Foreign currency 366,193 26,384 7,615 494,461 51,311 — Foreign currency forwards Foreign currency 1,025,548 43,441 — 911,197 50,974 — Total hedging derivatives 1,826,741 69,825 42,082 1,840,658 102,285 27,257 Total derivatives $ 20,355,622 $ 358,455 $ 1,080,720 $ 19,884,691 $ 356,666 $ 990,895 Fair Value Hedges The Company designates and reports certain foreign currency swaps to hedge the foreign currency fair value exposure of foreign currency denominated assets as fair value hedges when they meet the requirements of the general accounting principles for Derivatives and Hedging . The gain or loss on the hedged item attributable to a change in foreign currency and the offsetting gain or loss on the related foreign currency swaps as of September 30, 2019 and 2018, were (dollars in thousands): Type of Fair Value Hedge Hedged Item Gains (Losses) Recognized for Derivatives Gains (Losses) Recognized for Hedged Items Investment Related Gains (Losses) For the three months ended September 30, 2019: Foreign currency swaps Foreign-denominated fixed maturity securities $ (5,995 ) $ 4,088 For the three months ended September 30, 2018: Foreign currency swaps Foreign-denominated fixed maturity securities $ (2,258 ) $ 2,832 For the nine months ended September 30, 2019: Foreign currency swaps Foreign-denominated fixed maturity securities $ (10,422 ) $ 4,503 For the nine months ended September 30, 2018: Foreign currency swaps Foreign-denominated fixed maturity securities $ (5,284 ) $ 9,666 Cash Flow Hedges Certain derivative instruments are designated as cash flow hedges when they meet the requirements of the general accounting principles for Derivatives and Hedging . The Company designates and accounts for the following as cash flow hedges: (i) certain interest rate swaps, in which the cash flows of assets and liabilities are variable based on a benchmark rate; and (ii) certain interest rate swaps, in which the cash flows of assets are denominated in different currencies, commonly referred to as cross-currency swaps. The following table presents the components of AOCI, before income tax, and the condensed consolidated income statement classification where the gain or loss is recognized related to cash flow hedges for the three and nine months ended September 30, 2019 and 2018 (dollars in thousands): Three months ended September 30, 2019 2018 Balance beginning of period $ (14,862 ) $ 22,656 Gains (losses) deferred in other comprehensive income (loss) (32,123 ) 6,671 Amounts reclassified to investment income 38 (50 ) Amounts reclassified to interest expense (255 ) (234 ) Balance end of period $ (47,202 ) $ 29,043 Nine months ended September 30, 2019 2018 Balance beginning of period $ 8,788 $ 2,619 Gains (losses) deferred in other comprehensive income (loss) (54,902 ) 26,586 Amounts reclassified to investment income 19 (270 ) Amounts reclassified to interest expense (1,107 ) 108 Balance end of period $ (47,202 ) $ 29,043 As of September 30, 2019 , the before-tax deferred net gains (losses) on derivative instruments recorded in AOCI that are expected to be reclassified to earnings during the next twelve months are approximately $0.1 million and $(0.8) million in investment income and interest expense, respectively. The following table presents the effect of derivatives in cash flow hedging relationships on the condensed consolidated statements of income and the condensed consolidated statements of comprehensive income for the three and nine months ended September 30, 2019 and 2018 (dollars in thousands): Derivative Type Gain (Loss) Deferred in AOCI Gain (Loss) Reclassified into Income from AOCI Investment Income Interest Expense For the three months ended September 30, 2019: Interest rate $ (24,846 ) $ — $ 255 Currency/Interest rate (7,277 ) (38 ) — Total $ (32,123 ) $ (38 ) $ 255 For the three months ended September 30, 2018: Interest rate $ 7,490 $ — $ 234 Currency/Interest rate (819 ) 50 — Total $ 6,671 $ 50 $ 234 For the nine months ended September 30, 2019: Interest rate $ (46,816 ) $ — $ 1,107 Currency/Interest rate (8,086 ) (19 ) — Total $ (54,902 ) $ (19 ) $ 1,107 For the nine months ended September 30, 2018: Interest rate $ 27,217 $ — $ (108 ) Currency/Interest rate (631 ) 270 — Total $ 26,586 $ 270 $ (108 ) Hedges of Net Investments in Foreign Operations The Company uses foreign currency swaps and foreign currency forwards to hedge a portion of its net investment in certain foreign operations against adverse movements in exchange rates. The following table illustrates the Company’s net investments in foreign operations (“NIFO”) hedges for the three and nine months ended September 30, 2019 and 2018 (dollars in thousands): Derivative Gains (Losses) Deferred in AOCI For the three months ended September 30, For the nine months ended September 30, Type of NIFO Hedge (1) 2019 2018 2019 2018 Foreign currency swaps $ 3,930 $ (5,877 ) $ (5,563 ) $ 11,125 Foreign currency forwards 16,427 (11,562 ) (7,669 ) 11,737 Total $ 20,357 $ (17,439 ) $ (13,232 ) $ 22,862 (1) There were no sales or substantial liquidations of net investments in foreign operations that would have required the reclassification of gains or losses from accumulated other comprehensive income (loss) into investment income during the periods presented. The cumulative foreign currency translation gain recorded in AOCI related to these hedges was $187.8 million and $201.0 million at September 30, 2019 and December 31, 2018 , respectively. If a hedged foreign operation was sold or substantially liquidated, the amounts in AOCI would be reclassified to the condensed consolidated statements of income. A pro rata portion would be reclassified upon partial sale of a hedged foreign operation. Non-qualifying Derivatives and Derivatives for Purposes Other Than Hedging The Company uses various other derivative instruments for risk management purposes that either do not qualify or have not been qualified for hedge accounting treatment. The gain or loss related to the change in fair value for these derivative instruments is recognized in investment related gains (losses), net in the condensed consolidated statements of income, except where otherwise noted. A summary of the effect of non-hedging derivatives, including embedded derivatives, on the Company’s condensed consolidated statements of income for the three and nine months ended September 30, 2019 and 2018 is as follows (dollars in thousands): Gain (Loss) for the three months ended September 30, Type of Non-hedging Derivative Income Statement Location of Gain (Loss) 2019 2018 Interest rate swaps Investment related gains (losses), net $ 38,701 $ (12,228 ) Financial futures Investment related gains (losses), net 322 (6,544 ) Foreign currency swaps Investment related gains (losses), net 867 — Foreign currency forwards Investment related gains (losses), net 337 (58 ) CPI swaps Investment related gains (losses), net (8,235 ) (4,223 ) Credit default swaps Investment related gains (losses), net 1,961 4,689 Equity options Investment related gains (losses), net 243 (9,793 ) Longevity swaps Other revenues 2,063 2,426 Mortality swaps Other revenues — 473 Subtotal 36,259 (25,258 ) Embedded derivatives in: Modified coinsurance or funds withheld arrangements Investment related gains (losses), net 8,508 (2,081 ) Indexed annuity products Interest credited (44,972 ) (25,347 ) Variable annuity products Investment related gains (losses), net (42,233 ) 32,133 Total non-hedging derivatives $ (42,438 ) $ (20,553 ) Gain (Loss) for the nine months ended September 30, Type of Non-hedging Derivative Income Statement Location of Gain (Loss) 2019 2018 Interest rate swaps Investment related gains (losses), net $ 96,079 $ (47,399 ) Financial futures Investment related gains (losses), net (29,641 ) (7,312 ) Foreign currency swaps Investment related gains (losses), net (4,790 ) — Foreign currency forwards Investment related gains (losses), net 571 3 CPI swaps Investment related gains (losses), net (23,898 ) (996 ) Credit default swaps Investment related gains (losses), net 21,539 5,371 Equity options Investment related gains (losses), net (27,269 ) (15,207 ) Longevity swaps Other revenues 6,390 6,983 Mortality swaps Other revenues (484 ) (326 ) Subtotal 38,497 (58,883 ) Embedded derivatives in: Modified coinsurance or funds withheld arrangements Investment related gains (losses), net 11,678 20,335 Indexed annuity products Interest credited (50,361 ) 6,523 Variable annuity products Investment related gains (losses), net (42,116 ) 62,242 Total non-hedging derivatives $ (42,302 ) $ 30,217 Credit Derivatives The following table presents the estimated fair value, maximum amount of future payments and weighted average years to maturity of credit default swaps sold by the Company at September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Rating Agency Designation of Referenced Credit Obligations (1) Estimated Fair Value of Credit Default Swaps Maximum Amount of Future Payments under Credit Default Swaps (2) Weighted Average Years to Maturity (3) Estimated Fair Value of Credit Default Swaps Maximum Amount of Future Payments under Credit Default Swaps (2) Weighted Average Years to Maturity (3) AAA/AA+/AA/AA-/A+/A/A- Single name credit default swaps $ 1,018 $ 117,500 1.6 $ 1,953 $ 152,000 2.2 Credit default swaps referencing indices 342 240,000 10.2 — — 0.0 Subtotal 1,360 357,500 7.4 1,953 152,000 2.2 BBB+/BBB/BBB- Single name credit default swaps 4,103 337,700 2.0 2,930 353,700 2.2 Credit default swaps referencing indices 111 632,600 2.9 (76 ) 817,600 6.4 Subtotal 4,214 970,300 2.6 2,854 1,171,300 5.1 BB+/BB/BB- Single name credit default swaps 175 10,000 2.7 30 15,000 0.7 Subtotal 175 10,000 2.7 30 15,000 0.7 Total $ 5,749 $ 1,337,800 3.9 $ 4,837 $ 1,338,300 4.7 (1) The rating agency designations are based on ratings from Standard and Poor’s (“S&P”). (2) Assumes the value of the referenced credit obligations is zero. (3) The weighted average years to maturity of the credit default swaps is calculated based on weighted average notional amounts. Netting Arrangements and Credit Risk Certain of the Company’s derivatives are subject to enforceable master netting arrangements and reported as a net asset or liability in the condensed consolidated balance sheets. The Company nets all derivatives that are subject to such arrangements. The Company has elected to include all derivatives, except embedded derivatives, in the tables below, irrespective of whether they are subject to an enforceable master netting arrangement or a similar agreement. See Note 4 – “Investments” for information regarding the Company’s securities borrowing, lending, repurchase and repurchase/reverse repurchase programs. The following table provides information relating to the Company’s derivative instruments as of September 30, 2019 and December 31, 2018 (dollars in thousands): Gross Amounts Not Offset in the Balance Sheet Gross Amounts Recognized Gross Amounts Offset in the Balance Sheet Net Amounts Presented in the Balance Sheet Financial Instruments (1) Cash Collateral Pledged/ Received Net Amount September 30, 2019: Derivative assets $ 237,180 $ (43,461 ) $ 193,719 $ — $ (205,890 ) $ (12,171 ) Derivative liabilities 91,551 (43,461 ) 48,090 (81,090 ) (60,080 ) (93,080 ) December 31, 2018: Derivative assets $ 247,069 $ (18,581 ) $ 228,488 $ — $ (235,611 ) $ (7,123 ) Derivative liabilities 46,030 (18,581 ) 27,449 (71,376 ) (24,080 ) (68,007 ) (1) Includes initial margin posted to a central clearing partner. The Company may be exposed to credit-related losses in the event of non-performance by counterparties to derivative financial instruments with a positive fair value. Generally, the credit exposure of the Company’s derivative contracts is limited to the fair value at the reporting date plus or minus any collateral posted or held by the Company. The Company had no credit exposure related to its derivative contracts, as of September 30, 2019 and December 31, 2018 , as the net amount of collateral pledged to the Company from counterparties exceeded the fair value of the derivative contracts. Derivatives may be exchange-traded or they may be privately negotiated contracts, which are referred to as over-the-counter (“OTC”) derivatives. Certain of the Company’s OTC derivatives are cleared and settled through central clearing counterparties (“OTC cleared”) and others are bilateral contracts between two counterparties. The Company manages its credit risk related to OTC derivatives by entering into transactions with creditworthy counterparties, maintaining collateral arrangements and through the use of master netting agreements that provide for a single net payment to be made by one counterparty to another at each due date and upon termination. The Company is only exposed to the default of the central clearing counterparties for OTC cleared derivatives, and these transactions require initial and daily variation margin collateral postings. Exchange-traded derivatives are settled on a daily basis, thereby reducing the credit risk exposure in the event of non-performance by counterparties to such financial instruments.

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Disclosures	Fair Value of Assets and Liabilities Fair Value Measurement General accounting principles for Fair Value Measurements and Disclosures define fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. These principles also establish a fair value hierarchy that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value and describes three levels of inputs that may be used to measure fair value: Level 1 - Unadjusted quoted prices in active markets for identical assets or liabilities. The Company’s Level 1 assets and liabilities are traded in active exchange markets. Level 2 - Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or market standard valuation techniques and assumptions that use significant inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the related assets or liabilities. Prices are determined using valuation methodologies such as discounted cash flow models and other similar techniques that require management’s judgment or estimation in developing inputs that are consistent with what other market participants would use when pricing similar assets and liabilities. Additionally, the Company’s embedded derivatives, all of which are associated with reinsurance treaties and longevity and mortality swaps, are classified in Level 3 since their values include significant unobservable inputs. For a discussion of the Company’s valuation methodologies for assets and liabilities measured at fair value and the fair value hierarchy, see Note 6 in the Notes to Consolidated Financial Statements included in the Company’s 2018 Annual Report. Assets and Liabilities by Hierarchy Level Assets and liabilities measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018 are summarized below (dollars in thousands): September 30, 2019: Fair Value Measurements Using: Total Level 1 Level 2 Level 3 Assets: Fixed maturity securities – available-for-sale: Corporate $ 30,353,219 $ — $ 28,547,959 $ 1,805,260 Canadian government 4,633,219 — 3,942,376 690,843 RMBS 2,439,842 — 2,416,762 23,080 ABS 2,822,635 — 2,719,526 103,109 CMBS 1,782,218 — 1,752,250 29,968 U.S. government 1,668,505 1,541,294 110,070 17,141 State and political subdivisions 1,190,103 — 1,180,150 9,953 Other foreign government 4,591,526 — 4,575,383 16,143 Total fixed maturity securities – available-for-sale 49,481,267 1,541,294 45,244,476 2,695,497 Equity securities 134,453 86,968 — 47,485 Funds withheld at interest – embedded derivatives 121,275 — — 121,275 Cash equivalents 927,175 922,291 4,884 — Short-term investments 89,130 17,375 68,898 2,857 Other invested assets: Derivatives: Interest rate swaps 73,085 — 73,085 — Foreign currency forwards 43,654 — 43,654 — Credit default swaps (7,174 ) — (7,174 ) — Equity options 6,150 — 6,150 — Foreign currency swaps 26,384 — 26,384 — FVO contractholder-directed unit-linked investments 252,277 197,195 55,082 — Total other invested assets 394,376 197,195 197,181 — Other assets - longevity swaps 51,620 — — 51,620 Total $ 51,199,296 $ 2,765,123 $ 45,515,439 $ 2,918,734 Liabilities: Interest sensitive contract liabilities – embedded derivatives $ 989,170 $ — $ — $ 989,170 Other liabilities: Derivatives: Interest rate swaps 26,024 — 26,024 — Foreign currency swaps - non-hedged 12,454 — 12,454 — Foreign currency forwards (124 ) — (124 ) — CPI swaps 32,885 — 32,885 — Credit default swaps (12,923 ) — (12,923 ) — Equity options (18,694 ) — (18,694 ) — Foreign currency swaps 7,615 — 7,615 — Mortality swaps 853 — — 853 Total $ 1,037,260 $ — $ 47,237 $ 990,023 December 31, 2018: Fair Value Measurements Using: Total Level 1 Level 2 Level 3 Assets: Fixed maturity securities – available-for-sale: Corporate $ 23,982,119 $ — $ 22,651,194 $ 1,330,925 Canadian government 3,892,385 — 3,364,261 528,124 RMBS 1,869,221 — 1,862,366 6,855 ABS 2,149,204 — 2,053,632 95,572 CMBS 1,419,034 — 1,419,012 22 U.S. government 2,185,874 2,067,529 100,320 18,025 State and political subdivisions 752,194 — 741,992 10,202 Other foreign government 3,742,315 — 3,737,309 5,006 Total fixed maturity securities – available-for-sale 39,992,346 2,067,529 35,930,086 1,994,731 Equity securities 82,197 48,737 — 33,460 Funds withheld at interest – embedded derivatives 109,597 — — 109,597 Cash equivalents 485,167 473,509 11,658 — Short-term investments 105,991 4,989 98,774 2,228 Other invested assets: Derivatives: Interest rate swaps 37,976 — 37,976 — Foreign currency forwards 50,740 — 50,740 — Credit default swaps 4,466 — 4,466 — Equity options 36,206 — 36,206 — Foreign currency swaps 51,311 — 51,311 — FVO contractholder-directed unit-linked investments 197,770 196,781 989 — Total other invested assets 378,469 196,781 181,688 — Other assets - longevity swaps 47,789 — — 47,789 Total $ 41,201,556 $ 2,791,545 $ 36,222,206 $ 2,187,805 Liabilities: Interest sensitive contract liabilities – embedded derivatives $ 944,865 $ — $ — $ 944,865 Other liabilities: Derivatives: Interest rate swaps 18,542 — 18,542 — Foreign currency swaps - non-hedged 4,155 — 4,155 — CPI swaps 11,384 — 11,384 — Credit default swaps (371 ) — (371 ) — Equity options (6,630 ) — (6,630 ) — Mortality swaps 369 — — 369 Total $ 972,314 $ — $ 27,080 $ 945,234 Transfers between Levels 1 and 2 Transfers between Levels 1 and 2 are made to reflect changes in observability of inputs and market activity. The Company recognizes transfers of assets and liabilities into and out of levels within the fair value hierarchy at the beginning of the quarter in which the actual event or change in circumstances that caused the transfer occurs. There were no transfers between Level 1 and Level 2 during the nine months ended September 30, 2019 or 2018. Quantitative Information Regarding Internally - Priced Assets and Liabilities The following table presents quantitative information about significant unobservable inputs used in Level 3 fair value measurements that are developed internally by the Company as of September 30, 2019 and December 31, 2018 (dollars in thousands): Estimated Fair Value Valuation Technique Unobservable Inputs Range (Weighted Average) September 30, 2019 December 31, 2018 September 30, 2019 December 31, 2018 Assets: Corporate $ 888,946 $ 642,647 Market comparable securities Liquidity premium 0-5% (1%) 0-5% (1%) EBITDA Multiple 5.2x-6.1x (5.8x) 5.9x-7.5x (6.5x) ABS 102,027 77,842 Market comparable securities Liquidity premium 0-4% (1%) 0-1% (1%) U.S. government 17,141 18,025 Market comparable securities Liquidity premium 0-1% (1%) 0-1% (1%) Other foreign government 16,143 5,006 Market comparable securities Liquidity premium 0-1% (1%) 1 % Equity securities 30,681 25,007 Market comparable securities Liquidity premium 4 % 4 % EBITDA Multiple 6.9x-9.3x (7.9x) 6.9x-12.3x (7.9x) Funds withheld at interest- embedded derivatives 121,275 109,597 Total return swap Mortality 0-100% (2%) 0-100% (2%) Lapse 0-35% (12%) 0-35% (10%) Withdrawal 0-5% (3%) 0-5% (3%) CVA 0-5% (1%) 0-5% (1%) Crediting rate 2-4% (2%) 2-4% (2%) Longevity swaps 51,620 47,789 Discounted cash flow Mortality 0-100% (2%) 0-100% (2%) Mortality improvement (10%)-10% (3%) (10%)-10% (3%) Liabilities: Interest sensitive contract liabilities- embedded derivatives- indexed annuities 779,128 776,940 Discounted cash flow Mortality 0-100% (2%) 0-100% (2%) Lapse 0-35% (12%) 0-35% (10%) Withdrawal 0-5% (3%) 0-5% (3%) Option budget projection 2-4% (2%) 2-4% (2%) Interest sensitive contract liabilities- embedded derivatives- variable annuities 210,041 167,925 Discounted cash flow Mortality 0-100% (1%) 0-100% (1%) Lapse 0-25% (5%) 0-25% (5%) Withdrawal 0-7% (5%) 0-7% (5%) CVA 0-5% (1%) 0-5% (1%) Long-term volatility 0-27% (12%) 0-27% (13%) Mortality swaps 853 369 Discounted cash flow Mortality 0-100% (1%) 0-100% (1%) Changes in Level 3 Assets and Liabilities Assets and liabilities transferred into Level 3 are due to a lack of observable market transactions and price information. Transfers out of Level 3 are primarily the result of the Company obtaining observable pricing information or a third party pricing quotation that appropriately reflects the fair value of those assets and liabilities. In 2018, the Company transferred equity securities with a fair value of approximately $38.9 million into Level 3 as a result of the adoption of the new accounting guidance for the recognition and measurement of equity securities (see “New Accounting Pronouncements - Financial Instruments - Recognition and Measurement” in Note 2 - “Significant Accounting Policies and Pronouncements” in the Notes to Consolidated Financial Statements included in the Company’s 2018 Annual Report). For further information on the Company’s valuation processes, see Note 6 in the Notes to Consolidated Financial Statements included in the Company’s 2018 Annual Report. The reconciliations for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) are as follows (dollars in thousands): For the three months ended September 30, 2019: Fixed maturity securities - available-for-sale Corporate Canadian government RMBS ABS Fair value, beginning of period $ 1,644,364 $ 671,027 $ 16,032 $ 110,322 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses 318 3,713 (113 ) 3 Included in other comprehensive income 17,090 16,103 150 (51 ) Purchases (1) 214,025 — — 10,764 Sales (1) (34,363 ) — — — Settlements (1) (63,216 ) — (2,370 ) (17,929 ) Transfers into Level 3 27,042 — 15,421 — Transfers out of Level 3 — — (6,040 ) — Fair value, end of period $ 1,805,260 $ 690,843 $ 23,080 $ 103,109 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ 344 $ 3,713 $ (113 ) $ 3 For the three months ended September 30, 2019 (continued): Fixed maturity securities available-for-sale CMBS U.S. government State Other foreign government Equity securities Fair value, beginning of period $ 19 $ 17,406 $ 9,855 $ 15,686 $ 44,807 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — (90 ) 6 — — Investment related gains (losses), net — — — — 2,737 Included in other comprehensive income (975 ) 79 132 457 — Purchases (1) 1,155 104 — — 821 Sales (1) — — — — (880 ) Settlements (1) (3 ) (358 ) (40 ) — — Transfers into Level 3 29,772 — — — — Fair value, end of period $ 29,968 $ 17,141 $ 9,953 $ 16,143 $ 47,485 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ (90 ) $ 6 $ — $ — Investment related gains (losses), net — — — — 2,638 For the three months ended September 30, 2019 (continued): Funds withheld at interest- embedded derivatives Short-term Investments Other assets - longevity swaps Interest sensitive contract liabilities embedded derivatives Other liabilities - mortality swaps Fair value, beginning of period $ 112,767 $ 28,387 $ 51,755 $ (908,491 ) $ (853 ) Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — 133 — — — Investment related gains (losses), net 8,508 — — (42,233 ) — Interest credited — — — (44,972 ) — Included in other comprehensive income — (266 ) (2,198 ) — — Other revenues — — 2,063 — — Purchases (1) — 1,656 — (16,887 ) — Sales (1) — — — — — Settlements (1) — (11 ) — 23,413 — Transfers out of Level 3 — (27,042 ) — — — Fair value, end of period $ 121,275 $ 2,857 $ 51,620 $ (989,170 ) $ (853 ) Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ 133 $ — $ — $ — Investment related gains (losses), net 8,508 — — (44,965 ) — Other revenues — — 2,063 — — Interest credited — — — (68,385 ) — For the nine months ended September 30, 2019: Fixed maturity securities - available-for-sale Corporate Canadian government RMBS ABS Fair value, beginning of period $ 1,330,925 $ 528,124 $ 6,855 $ 95,572 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses 478 10,775 (132 ) 25 Investment related gains (losses), net 15 — — 110 Included in other comprehensive income 53,222 151,944 221 1,972 Purchases (1) 604,897 — 3,018 50,511 Sales (1) (59,000 ) — — — Settlements (1) (166,865 ) — (3,945 ) (45,081 ) Transfers into Level 3 43,083 — 23,103 — Transfers out of Level 3 (1,495 ) — (6,040 ) — Fair value, end of period $ 1,805,260 $ 690,843 $ 23,080 $ 103,109 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ 580 $ 10,775 $ (132 ) $ 24 For the nine months ended September 30, 2019 (continued): Fixed maturity securities available-for-sale CMBS U.S. government State Other foreign government Equity securities Fair value, beginning of period $ 22 $ 18,025 $ 10,202 $ 5,006 $ 33,460 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — (265 ) 16 — — Investment related gains (losses), net — — — — 8,284 Included in other comprehensive income (975 ) 668 164 1,137 — Purchases (1) 1,155 290 — 10,000 6,621 Sales (1) — — — — (880 ) Settlements (1) (6 ) (1,577 ) (429 ) — — Transfers into Level 3 29,772 — — — — Fair value, end of period $ 29,968 $ 17,141 $ 9,953 $ 16,143 $ 47,485 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ (265 ) $ 16 $ — $ — Investment related gains (losses), net — — — — 8,185 For the nine months ended September 30, 2019 (continued): Funds withheld at interest- embedded derivatives Cash equivalents Short-term Investments Other assets - longevity swaps Interest sensitive contract liabilities embedded derivatives Other liabilities - mortality swaps Fair value, beginning of period $ 109,597 $ — $ 2,228 $ 47,789 $ (944,865 ) $ (369 ) Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — — 221 — — — Investment related gains (losses), net 11,678 — 17 — (42,116 ) — Interest credited — — — — (50,361 ) — Included in other comprehensive income — — (134 ) (2,559 ) — — Other revenues — — — 6,390 — (484 ) Purchases (1) — 19 29,664 — (12,904 ) — Sales (1) — — (1,517 ) — — — Settlements (1) — — (558 ) — 61,076 — Transfers out of Level 3 — (19 ) (27,064 ) — — — Fair value, end of period $ 121,275 $ — $ 2,857 $ 51,620 $ (989,170 ) $ (853 ) Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ — $ 221 $ — $ — $ — Investment related gains (losses), net 11,678 — — — (48,041 ) — Other revenues — — — 6,390 — (484 ) Interest credited — — — — (111,436 ) — For the three months ended September 30, 2018: Fixed maturity securities - available-for-sale Corporate Canadian government RMBS ABS Fair value, beginning of period $ 1,367,154 $ 572,698 $ 54,839 $ 70,686 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses (156 ) 3,520 3 20 Investment related gains (losses), net 239 — — 626 Included in other comprehensive income (4,858 ) (27,476 ) (1 ) (130 ) Purchases (1) 123,808 — — 11,099 Sales (1) (62,047 ) — — (462 ) Settlements (1) (101,868 ) — (3 ) (24,166 ) Transfers into Level 3 2,782 — — 64,009 Transfers out of Level 3 (69,119 ) — (54,838 ) (38,915 ) Fair value, end of period $ 1,255,935 $ 548,742 $ — $ 82,767 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ (180 ) $ 3,520 $ — $ 13 Investment related gains (losses), net (1,430 ) — — — For the three months ended September 30, 2018 (continued): Fixed maturity securities available-for-sale CMBS U.S. government State Other foreign government Fair value, beginning of period $ 1,867 $ 20,735 $ 16,505 $ 5,044 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — (107 ) 6 — Included in other comprehensive income 7 (122 ) (544 ) (32 ) Purchases (1) — 120 — — Settlements (1) (1 ) (374 ) (37 ) — Transfers into Level 3 1,752 — 9,859 — Transfers out of Level 3 (1,843 ) — (12,144 ) — Fair value, end of period $ 1,782 $ 20,252 $ 13,645 $ 5,012 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ (107 ) $ 6 $ — For the three months ended September 30, 2018 (continued): Equity securities Funds withheld at interest- embedded derivatives Short-term Investments Other assets - longevity swaps Interest sensitive contract liabilities embedded derivatives Other liabilities - mortality swaps Fair value, beginning of period $ 42,937 $ 144,610 $ 3,217 $ 43,971 $ (928,797 ) $ (782 ) Total gains/losses (realized/unrealized) Included in earnings, net: Investment related gains (losses), net 5,532 (2,081 ) — — 32,133 — Interest credited — — — — (25,348 ) — Included in other comprehensive income — — 47 (307 ) — 1 Other revenues — — — 2,426 — 473 Purchases (1) 863 — 1,721 — (4,231 ) — Sales (1) (5,847 ) — — — — — Settlements (1) — — — — 20,044 — Transfers out of Level 3 — — (2,782 ) — — — Fair value, end of period $ 43,485 $ 142,529 $ 2,203 $ 46,090 $ (906,199 ) $ (308 ) Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment related gains (losses), net $ 2,178 $ (2,081 ) $ — $ — $ 30,433 $ — Other revenues — — — 2,426 — 473 Interest credited — — — — (45,393 ) — For the nine months ended September 30, 2018: Fixed maturity securities - available-for-sale Corporate Canadian government RMBS ABS Fair value, beginning of period $ 1,337,272 $ 593,942 $ 107,882 $ 123,474 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses (822 ) 10,432 (132 ) 202 Investment related gains (losses), net (2,902 ) — 312 1,910 Included in other comprehensive income (35,532 ) (55,632 ) (1,782 ) (821 ) Purchases (1) 379,476 — 45,328 22,099 Sales (1) (79,316 ) — (4,961 ) (462 ) Settlements (1) (245,342 ) — (4,538 ) (46,449 ) Transfers into Level 3 9,948 — 3,031 68,977 Transfers out of Level 3 (106,847 ) — (145,140 ) (86,163 ) Fair value, end of period $ 1,255,935 $ 548,742 $ — $ 82,767 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ (845 ) $ 10,432 $ — $ 187 Investment related gains (losses), net (4,571 ) — — — For the nine months ended September 30, 2018 (continued): Fixed maturity securities available-for-sale CMBS U.S. government State Other foreign government Fair value, beginning of period $ 3,234 $ 22,511 $ 41,203 $ 5,092 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — (324 ) 4 — Included in other comprehensive income (56 ) (635 ) 46 (80 ) Purchases (1) — 334 — — Settlements (1) (4 ) (1,634 ) (158 ) — Transfers into Level 3 1,752 — 9,859 — Transfers out of Level 3 (3,144 ) — (37,309 ) — Fair value, end of period $ 1,782 $ 20,252 $ 13,645 $ 5,012 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ (325 ) $ 3 $ — For the nine months ended September 30, 2018 (continued): Equity securities Funds withheld at interest- embedded derivatives Short-term Investments Other assets - longevity swaps Interest sensitive contract liabilities embedded derivatives Other liabilities - mortality swaps Fair value, beginning of period $ — $ 122,194 $ 3,096 $ 40,659 $ (1,014,228 ) $ (1,683 ) Total gains/losses (realized/unrealized) Included in earnings, net: Investment related gains (losses), net (2,067 ) 20,335 — — 62,242 — Interest credited — — — — 6,523 — Included in other comprehensive income — — 1 (1,552 ) — 1 Other revenues — — — 6,983 — (326 ) Purchases (1) 13,111 — 2,202 — (16,946 ) — Sales (1) (6,416 ) — — — — — Settlements (1) (48 ) — (314 ) — 56,210 1,700 Transfers into Level 3 38,905 — — — — — Transfers out of Level 3 — — (2,782 ) — — — Fair value, end of period $ 43,485 $ 142,529 $ 2,203 $ 46,090 $ (906,199 ) $ (308 ) Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment related gains (losses), net $ (5,527 ) $ 20,335 $ — $ — $ 56,808 $ — Other revenues — — — 6,983 — (326 ) Interest credited — — — — (49,688 ) — (1) The amount reported within purchases, sales and settlements is the purchase price (for purchases) and the sales/settlement proceeds (for sales and settlements) based upon the actual date purchased or sold/settled. Items purchased and sold/settled in the same period are excluded from the rollforward. The Company had no issuances during the period. Nonrecurring Fair Value Measurements The following table (dollars in thousands) presents information for assets measured at an estimated fair value on a nonrecurring basis during the 2019 and 2018 periods presented and still held at the reporting date (for example, when there is evidence of impairment). The estimated fair values for these assets were determined using significant unobservable inputs (Level 3). Carrying Value After Measurement Investment Related Gains (Losses), Net At September 30, Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 2019 2018 Limited partnership interests (1) $ 17,785 $ 2,246 $ (3,537 ) $ (1,860 ) $ (8,586 ) $ (1,860 ) (1) The impaired limited partnership interests presented above were accounted for using the cost method. Impairments on these cost method investments were recognized at estimated fair value determined using the net asset values of the Company’s ownership interest as provided in the financial statements of the investees. The market for these investments has limited activity and price transparency. Fair Value of Financial Instruments The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments, which were not measured at fair value on a recurring basis, as of September 30, 2019 and December 31, 2018 (dollars in thousands). For additional information regarding the methods and significant assumptions used by the Company to estimate these fair values, see Note 6 in the Notes to Consolidated Financial Statements included in the Company’s 2018 Annual Report. This table excludes any payables or receivables for collateral under repurchase agreements and other transactions. The estimated fair value of the excluded amount approximates carrying value as they equal the amount of cash collateral received/paid. September 30, 2019: Carrying Value (1) Estimated Fair Value Fair Value Measurement Using: Level 1 Level 2 Level 3 NAV Assets: Mortgage loans on real estate $ 5,647,265 $ 5,936,051 $ — $ — $ 5,936,051 $ — Policy loans 1,289,868 1,289,868 — 1,289,868 — — Funds withheld at interest 5,476,148 5,873,575 — — 5,873,575 — Cash and cash equivalents 1,708,421 1,708,421 1,708,421 — — — Short-term investments 18,373 18,373 18,373 — — — Other invested assets 1,147,167 1,205,284 5,208 82,360 737,064 380,652 Accrued investment income 520,301 520,301 — 520,301 — — Liabilities: Interest-sensitive contract liabilities $ 18,747,630 $ 20,446,240 $ — $ — $ 20,446,240 $ — Long-term debt 3,381,406 3,564,595 — — 3,564,595 — Collateral finance and securitization notes 610,246 561,011 — — 561,011 — December 31, 2018: Carrying Value (1) Estimated Fair Value Fair Value Measurement Using: Level 1 Level 2 Level 3 NAV Assets: Mortgage loans on real estate $ 4,966,298 $ 4,917,416 $ — $ — $ 4,917,416 $ — Policy loans 1,344,980 1,344,980 — 1,344,980 — — Funds withheld at interest 5,655,055 5,802,518 — — 5,802,518 — Cash and cash equivalents 1,404,566 1,404,566 1,404,566 — — — Short-term investments 36,607 36,607 36,607 — — — Other invested assets 945,731 941,449 4,640 83,203 477,214 376,392 Accrued investment income 427,893 427,893 — 427,893 — — Liabilities: Interest-sensitive contract liabilities $ 14,547,436 $ 14,611,011 $ — $ — $ 14,611,011 $ — Long-term debt 2,787,873 2,752,047 — — 2,752,047 — Collateral finance and securitization notes 681,961 626,731 — — 626,731 — (1) Carrying values presented herein may differ from those in the Company’s condensed consolidated balance sheets because certain items within the respective financial statement captions may be measured at fair value on a recurring basis.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information The accounting policies of the segments are the same as those described in the Significant Accounting Policies and Pronouncements in Note 2 of the consolidated financial statements accompanying the 2018 Annual Report. The Company measures segment performance primarily based on profit or loss from operations before income taxes. There are no intersegment reinsurance transactions and the Company does not have any material long-lived assets. The Company allocates capital to its segments based on an internally developed economic capital model, the purpose of which is to measure the risk in the business and to provide a basis upon which capital is deployed. The economic capital model considers the unique and specific nature of the risks inherent in the Company’s businesses. As a result of the economic capital allocation process, a portion of investment income is attributed to the segments based on the level of allocated capital. In addition, the segments are charged for excess capital utilized above the allocated economic capital basis. This charge is included in policy acquisition costs and other insurance expenses. The Company has geographic-based and business-based operational segments. Geographic-based operations are further segmented into traditional and financial solutions businesses. Information related to revenues, income (loss) before income taxes and total assets of the Company for each reportable segment are summarized below (dollars in thousands). Three months ended September 30, Nine months ended September 30, Revenues: 2019 2018 2019 2018 U.S. and Latin America: Traditional $ 1,609,866 $ 1,547,790 $ 4,735,208 $ 4,601,631 Financial Solutions 382,672 290,848 938,589 734,148 Total 1,992,538 1,838,638 5,673,797 5,335,779 Canada: Traditional 324,851 295,962 955,326 910,480 Financial Solutions 24,204 12,168 71,707 37,034 Total 349,055 308,130 1,027,033 947,514 Europe, Middle East and Africa: Traditional 378,110 357,059 1,131,615 1,123,379 Financial Solutions 116,800 91,664 340,207 280,482 Total 494,910 448,723 1,471,822 1,403,861 Asia Pacific: Traditional 685,886 578,035 1,992,475 1,763,094 Financial Solutions 45,702 16,167 159,788 54,005 Total 731,588 594,202 2,152,263 1,817,099 Corporate and Other 59,474 37,838 190,089 92,893 Total $ 3,627,565 $ 3,227,531 $ 10,515,004 $ 9,597,146 Three months ended September 30, Nine months ended September 30, Income (loss) before income taxes: 2019 2018 2019 2018 U.S. and Latin America: Traditional $ 112,542 $ 116,328 $ 179,371 $ 191,198 Financial Solutions 118,876 87,073 294,171 236,882 Total 231,418 203,401 473,542 428,080 Canada: Traditional 43,684 21,149 140,222 66,661 Financial Solutions 3,108 1,646 8,269 8,381 Total 46,792 22,795 148,491 75,042 Europe, Middle East and Africa: Traditional 25,342 18,370 56,887 40,259 Financial Solutions 61,246 56,205 151,437 160,738 Total 86,588 74,575 208,324 200,997 Asia Pacific: Traditional 21,453 62,007 92,852 143,756 Financial Solutions 1,886 206 9,887 8,365 Total 23,339 62,213 102,739 152,121 Corporate and Other (41,047 ) (40,323 ) (109,365 ) (148,366 ) Total $ 347,090 $ 322,661 $ 823,731 $ 707,874 Assets: September 30, 2019 December 31, 2018 U.S. and Latin America: Traditional $ 19,035,387 $ 19,235,781 Financial Solutions 25,522,131 19,870,388 Total 44,557,518 39,106,169 Canada: Traditional 4,248,447 4,200,792 Financial Solutions 81,684 154,000 Total 4,330,131 4,354,792 Europe, Middle East and Africa: Traditional 3,774,565 3,643,174 Financial Solutions 6,094,334 4,737,529 Total 9,868,899 8,380,703 Asia Pacific: Traditional 6,440,974 5,680,978 Financial Solutions 1,671,502 1,180,745 Total 8,112,476 6,861,723 Corporate and Other 8,904,961 5,831,858 Total $ 75,773,985 $ 64,535,245

Commitments, Contingencies and

Commitments, Contingencies and Guarantees	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	Commitments, Contingencies and Guarantees Commitments Funding of Investments The Company’s commitments to fund investments as of September 30, 2019 and December 31, 2018 are presented in the following table (dollars in thousands): September 30, 2019 December 31, 2018 Limited partnership interests and joint ventures $ 619,582 $ 523,903 Commercial mortgage loans 111,110 22,605 Bank loans and private placements 188,648 137,076 Lifetime mortgages 44,910 264,858 The Company anticipates that the majority of its current commitments will be invested over the next five years; however, these commitments could become due any time at the request of the counterparties. Bank loans and private placements are included in fixed maturity securities available-for-sale. Contingencies Litigation The Company is subject to litigation in the normal course of its business. The Company currently has no material litigation. A legal reserve is established when the Company is notified of an arbitration demand or litigation or is notified that an arbitration demand or litigation is imminent, it is probable that the Company will incur a loss as a result and the amount of the probable loss is reasonably capable of being estimated. Other Contingencies The Company indemnifies its directors and officers as provided in its charters and by-laws. Since this indemnity generally is not subject to limitation with respect to duration or amount, the Company does not believe that it is possible to determine the maximum potential amount due under this indemnity in the future. Guarantees Statutory Reserve Support RGA, through wholly-owned subsidiaries, has committed to provide statutory reserve support to third parties, in exchange for a fee, by funding loans if certain defined events occur. Such statutory reserves are required under the U.S. Valuation of Life Policies Model Regulation (commonly referred to as Regulation XXX for term life insurance policies and Regulation A-XXX for universal life secondary guarantees). The third parties have recourse to RGA should the subsidiary fail to provide the required funding, however, as of September 30, 2019 , the Company does not believe that it will be required to provide any funding under these commitments as the occurrence of the defined events is considered remote. The following table presents the maximum potential obligation for these commitments as of September 30, 2019 (dollars in millions): Commitment Period: Maximum Potential Obligation 2023 $ 500.0 2034 2,000.0 2035 1,314.2 2036 2,658.0 2037 5,750.0 2038 1,800.0 2039 1,750.0 Other Guarantees RGA has issued guarantees to third parties on behalf of its subsidiaries for the payment of amounts due under certain securities borrowing and repurchase arrangements, financing arrangements and office lease obligations, whereby, if a subsidiary fails to meet an obligation, RGA or one of its other subsidiaries will make a payment to fulfill the obligation. Additionally, in limited circumstances, treaty guarantees are granted to ceding companies in order to provide them additional security, particularly in cases where RGA’s subsidiary is relatively new, unrated, or not of a significant size, relative to the ceding company. Liabilities supported by the treaty guarantees, before consideration of any legally offsetting amounts due from the guaranteed party are reflected on the Company’s condensed consolidated balance sheets in future policy benefits. Potential guaranteed amounts of future payments will vary depending on production levels and underwriting results. Guarantees related to securities borrowing and repurchase arrangements provide additional security to third parties should a subsidiary fail to provide securities when due. RGA’s guarantees issued as of September 30, 2019 and December 31, 2018 are reflected in the following table (dollars in thousands): September 30, 2019 December 31, 2018 Treaty guarantees $ 1,764,146 $ 1,392,352 Treaty guarantees, net of assets in trust 902,008 1,291,445 Securities borrowing and repurchase arrangements 273,295 269,980 Financing arrangements 41,246 61,273 Lease obligations — 392

Income Tax

Income Tax	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Text Block]	Income Tax The provision for income tax expense differed from the amounts computed by applying the U.S. federal income tax statutory rate of 21.0% to pre-tax income as a result of the following for the three and nine months ended September 30, 2019 and 2018 , respectively (dollars in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Tax provision at U.S. statutory rate $ 72,889 $ 67,759 $ 172,984 $ 148,654 Increase (decrease) in income taxes resulting from: U.S. Tax Reform provisional adjustments — 664 — (2,685 ) U.S. Tax Reform valuation allowance adjustments — (58,949 ) — (59,139 ) Foreign tax rate differing from U.S. tax rate 84 7,537 1,373 8,795 Differences in tax bases in foreign jurisdictions (9,550 ) (2,371 ) (30,626 ) (9,264 ) Deferred tax valuation allowance 27,721 (5,334 ) 50,607 5,357 Amounts related to tax audit contingencies 3,259 1,851 6,223 650 Corporate rate changes 116 (166 ) (1,621 ) 30 Subpart F (26 ) (99 ) 440 211 Foreign tax credits (651 ) (544 ) (759 ) (1,003 ) Global intangible low-taxed income, net of credit — 7,624 — 11,916 Equity compensation excess benefit (1,034 ) (817 ) (6,189 ) (5,067 ) Return to provision adjustments (8,362 ) 4,213 (4,400 ) 4,108 Other, net (121 ) 94 729 (492 ) Total provision for income taxes $ 84,325 $ 21,462 $ 188,761 $ 102,071 Effective tax rate 24.3 % 6.7 % 22.9 % 14.4 % The effective tax rates for the third quarter and first nine months of 2019 were higher than the U.S. Statutory rate of 21.0% primarily as a result of valuation allowances established on deferred tax assets in foreign jurisdictions and the accrual of uncertain tax positions, which was partially offset by differences in tax bases of foreign jurisdictions, return to provision adjustments, and tax benefits related to equity compensation. The effective tax rates for the third quarter and first nine months of 2018 were lower than the U.S. Statutory rate of 21.0% primarily as a result of the release of a valuation allowance on foreign tax credits, which was partially offset by income earned in jurisdictions with statutory rate higher than the U.S. tax rate and a tax expense related to global intangible low-taxed income. During the third quarter of 2018 the Company released an uncertain tax position due to the expiration of the statute of limitations and established a new position. The foreign tax credits were used to offset the new uncertain tax liability, resulting in a valuation allowance no longer being necessary. $58.9 million of the release of the valuation allowance was previously established as part of U.S. Tax Reform.

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans The components of net periodic benefit costs, included in other operating expenses on the condensed consolidated statements of income, for the three and nine months ended September 30, 2019 and 2018 were as follows (dollars in thousands): Pension Benefits Other Benefits Three months ended September 30, Three months ended September 30, 2019 2018 2019 2018 Service cost $ 3,158 $ 3,106 $ 461 $ 999 Interest cost 1,662 1,341 827 680 Expected return on plan assets (1,788 ) (1,884 ) — — Amortization of prior service cost (credit) 61 82 (328 ) (328 ) Amortization of prior actuarial losses 1,073 929 29 937 Net periodic benefit cost $ 4,166 $ 3,574 $ 989 $ 2,288 Pension Benefits Other Benefits Nine months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Service cost $ 9,465 $ 9,330 $ 1,975 $ 2,271 Interest cost 4,979 4,028 1,986 1,739 Expected return on plan assets (5,364 ) (5,651 ) — — Amortization of prior service cost (credit) 182 247 (986 ) (986 ) Amortization of prior actuarial losses 3,215 2,792 1,317 1,933 Net periodic benefit cost $ 12,477 $ 10,746 $ 4,292 $ 4,957

Reinsurance

Reinsurance	9 Months Ended
	Sep. 30, 2019
Retrocession Arrangements And Reinsurance Ceded Receivables [Abstract]
Retrocession Arrangements and Reinsurance Ceded Receivables	Reinsurance Retrocession reinsurance treaties do not relieve the Company from its obligations to direct writing companies. Failure of retrocessionaires to honor their obligations could result in losses to the Company. Consequently, allowances would be established for amounts deemed uncollectible. At September 30, 2019 and December 31, 2018 , no allowances were deemed necessary. The Company regularly evaluates the financial condition of the insurance companies from which it assumes and to which it cedes reinsurance. Retrocessions are arranged through the Company’s retrocession pools for amounts in excess of the Company’s retention limit. As of September 30, 2019 and December 31, 2018 , all rated retrocession pool participants followed by the A.M. Best Company were rated “A- (excellent)” or better. The Company verifies retrocession pool participants’ ratings on a quarterly basis. For a majority of the retrocessionaires that were not rated, security in the form of letters of credit or trust assets has been posted. In addition, the Company performs annual financial reviews of its retrocessionaires to evaluate financial stability and performance. The following table presents information for the Company’s reinsurance ceded receivable assets, including the respective amount and A.M. Best rating for each reinsurer representing in excess of five percent of the total as of September 30, 2019 or December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Reinsurer A.M. Best Rating Amount % of Total Amount % of Total Reinsurer A A+ $ 358,845 41.6 % $ 303,036 40.0 % Reinsurer B A+ 201,011 23.3 193,324 25.5 Reinsurer C A 76,807 8.9 69,885 9.2 Reinsurer D A++ 57,247 6.6 36,600 4.8 Reinsurer E A+ 40,816 4.7 40,004 5.3 Other reinsurers 128,301 14.9 114,723 15.2 Total $ 863,027 100.0 % $ 757,572 100.0 % Included in the total reinsurance ceded receivables balance were $189.9 million and $242.8 million of claims recoverable, of which $15.6 million and $17.4 million were in excess of 90 days past due, as of September 30, 2019 and December 31, 2018

Policy Claims and Benefits (Not

Policy Claims and Benefits (Notes)	9 Months Ended
	Sep. 30, 2019
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]	Policy Claims and Benefits The liability for unpaid claims is reported in future policy benefits and other policy-related balances within the Company’s consolidated balance sheet. Activity associated with unpaid claims is summarized below (dollars in thousands): Nine months ended September 30, 2019 2018 Balance at beginning of year $ 6,584,668 $ 5,896,469 Less: reinsurance recoverable (432,582 ) (455,547 ) Net balance at beginning of year 6,152,086 5,440,922 Incurred: Current year 8,203,842 7,534,297 Prior years 108,023 97,336 Total incurred 8,311,865 7,631,633 Payments: Current year (2,937,099 ) (2,748,547 ) Prior years (4,774,623 ) (4,222,550 ) Total payments (7,711,722 ) (6,971,097 ) Other changes: Interest accretion 19,887 18,550 Foreign exchange adjustments (99,788 ) (153,247 ) Total other changes (79,901 ) (134,697 ) Net balance at end the period 6,672,328 5,966,761 Plus: reinsurance recoverable 508,003 424,545 Balance at end of the period $ 7,180,331 $ 6,391,306 Incurred claims related to prior years reflected in the table above resulted in part from developed claims for prior years being different than were anticipated when the liabilities for unpaid claims were originally estimated. These trends have been considered in establishing the current year liability for unpaid claims.

Financing Activities

Financing Activities	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Financing Activities On May 15, 2019 , RGA issued 3.9% Senior Notes due May 15, 2029 with a face amount of $600.0 million . The net proceeds were approximately $593.8 million and will be used in part to repay upon maturity the Company’s $400.0 million 6.45% Senior Notes that mature in November 2019. The remainder will be used for general corporate purposes. Capitalized issue costs were approximately $4.8 million .

New Accounting Standards

New Accounting Standards	9 Months Ended
	Sep. 30, 2019
Accounting Changes and Error Corrections [Abstract]
New Accounting Standards	New Accounting Standards Changes to the general accounting principles are established by the Financial Accounting Standards Board (“FASB”) in the form of accounting standards updates to the FASB Accounting Standards Codification™. Accounting standards updates not listed below were assessed and determined to be either not applicable or are expected to have minimal impact on the Company’s condensed consolidated financial statements. Description Date of Adoption Effect on the financial statements or other significant matters Standards adopted: Financial Instruments - Recognition and Measurement This guidance requires equity investments that are not accounted for under the equity method of accounting to be measured at fair value with changes recognized in net income and also updates certain presentation and disclosure requirements. January 1, 2018 This guidance required a cumulative-effect adjustment for certain items upon adoption. The adoption of the new guidance was not material to the Company's financial position. Compensation - Retirement Benefits - Defined Benefit Plans - General This guidance is part of the FASB’s disclosure framework project and eliminates certain disclosure requirements for defined benefit pension and other postretirement plans. Early adoption is permitted. December 31, 2018 This guidance was applied retrospectively to all periods presented in the year of adoption. The adoption of the new guidance was not material to the Company’s financial position. Leases This new standard, based on the principle that entities should recognize assets and liabilities arising from leases, does not significantly change the lessees’ recognition, measurement and presentation of expenses and cash flows from the previous accounting standard. Leases are classified as finance or operating. The new standard’s primary change is the requirement for entities to recognize a lease liability for payments and a right of use asset representing the right to use the leased asset during the term of operating lease arrangements. Lessees are permitted to make an accounting policy election to not recognize the asset and liability for leases with a term of twelve months or less. Lessors’ accounting is largely unchanged from the previous accounting standard. In addition, the new standard expands the disclosure requirements of lease arrangements. Early adoption is permitted. January 1, 2019 This guidance was adopted by applying the optional transition method. The adoption of the standard did not have a material impact on the Company’s results of operations or financial position. The adoption of the updated guidance resulted in the Company recognizing a right-to-use asset and lease liability of $55.2 million included in other assets and other liabilities, respectively, in the condensed consolidated balance sheets. Derivatives and Hedging This updated guidance improves the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements and make certain targeted improvements to simplify the application of the hedge accounting in current GAAP related to the assessment of hedge effectiveness. Early adoption is permitted. January 1, 2019 This guidance was adopted by applying a modified retrospective approach to existing hedging relationships as of the date of adoption. The adoption of the new standard did not have a material impact on the Company’s results of operations or financial position. Upon adoption of the guidance, the Company recorded an immaterial adjustment to retained earnings as of the beginning of the first reporting period in which the guidance was effective and modified some disclosures. Description Anticipated Date of Adoption Effect on the financial statements or other significant matters Standards not yet adopted: Financial Services - Insurance This guidance significantly changes how insurers account for long-duration insurance contracts. The new guidance also significantly expands the disclosure requirements of long-duration insurance contracts. The FASB has tentatively agreed to defer the original effective date by one year. Upon issuance of a final standard, the new guidance will be effective for annual and interim reporting periods beginning January 1, 2022. Below are the most significant areas of change: January 1, 2022 See each significant area of change below for the method of adoption and impact to the Company’s results of operations and financial position. Cash flow assumptions for measuring liability for future policy benefits The new guidance requires insurers to review, and if necessary, update the cash flow assumptions used to measure liabilities for future policy benefits periodically. The change in the liability estimate as a result of updating cash flow assumptions will be recognized in net income. Cash flow assumptions for measuring liability for future policy benefits The Company will likely adopt this guidance on a modified retrospective basis as of the earliest period presented in the year of adoption. The Company is currently evaluating the impact of this amendment on its results of operations and financial position but anticipates the updated guidance will likely have a material impact. Discount rate assumption for measuring liability for future policy benefits The new guidance requires insurers to update the discount rate assumption used to measure liabilities for future policy benefits at each reporting period, and the discount rate utilized must be based on an upper-medium grade fixed income instrument yield. The change in the liability estimate as a result of updating the discount rate assumption will be recognized in other comprehensive income. Discount rate assumption for measuring liability for future policy benefits The Company will likely adopt this guidance on a modified retrospective basis as of the earliest period presented in the year of adoption. The Company is currently evaluating the impact of this amendment on its results of operations and financial position but anticipates the updated guidance will likely have a material impact. Market risk benefits The new guidance created a new category of benefit features called market risk benefits that will be measured at fair value with changes in fair value attributable to a change in the instrument-specific credit risk recognized in other comprehensive income. Market risk benefits The Company will adopt this guidance on a retrospective basis as of the earliest period presented in the year of adoption. The Company is currently evaluating the impact of this amendment on its results of operations and financial position but anticipates the updated guidance will likely have a material impact. Amortization of deferred acquisition costs (“DAC”) and other balances The new guidance requires DAC and other balances to be amortized on a constant level basis over the expected term of the related contracts. Amortization of deferred acquisition costs (“DAC”) and other balances The Company will likely adopt this guidance on a modified retrospective basis as of the earliest period presented in the year of adoption. The Company is currently evaluating the impact of this amendment on its results of operations and financial position but anticipates the updated guidance will likely have a material impact. Financial Instruments - Credit Losses Financial Instruments - Credit Losses This guidance adds to U.S. GAAP an impairment model, known as current expected credit loss (“CECL”) model that is based on expected losses rather than incurred losses. For traditional and other receivables, held-to-maturity debt securities, loans and other instruments entities will be required to use the new forward-looking “expected loss” model that generally will result in earlier recognition of allowance for losses. For available-for-sale debt securities with unrealized losses, entities will measure credit losses similar to what they do today, except the losses will be recognized through an allowance for credit losses and adjusted each period for changes in credit risks. Early adoption is permitted. January 1, 2020 For asset classes within the scope of the CECL model, this guidance will be adopted through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective (that is, a modified-retrospective approach). For available-for-sale debt securities, this guidance will be applied prospectively. The Company is developing its expected credit loss models and related system processes and controls for assets held at amortized costs, the most significant of which are commercial mortgages and other loans. The allowance for credit losses will increase when this guidance is adopted to include expected losses over the lifetime of commercial mortgages and other loans, including reasonable and supportable forecasts and expected changes in future economic conditions. Based on a preliminary analysis performed in the third quarter of 2019 and forecasts of macroeconomic conditions and exposures at that time, the overall impact is estimated to be an approximate $15 million to $25 million increase in the allowance for credit losses. This increase will be reflected as a decrease to opening retained earnings, net of income taxes, as of January 1, 2020. The extent of the impact of the adoption of this guidance on the Company’s consolidated financial statements will depend on various factors including the economic environment, the size and type of commercial loans and the nature and size of transactions closed in the fourth quarter of 2019. Fair Value Measurement This guidance is part of the FASB’s disclosure framework project and eliminates certain disclosure requirements for fair value measurement, requires entities to disclose new information and modifies existing disclosure requirements. Early adoption is permitted. January 1, 2020 Certain disclosure changes in this guidance will be applied prospectively in the year of adoption. The remaining changes in this guidance will be applied retrospectively to all periods presented in the year of adoption. The Company does not expect the adoption of this guidance to have a material impact on its financial position.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table sets forth the computation of basic and diluted earnings per share on net income (in thousands, except per share information): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Earnings: Net income (numerator for basic and diluted calculations) $ 262,765 $ 301,199 $ 634,970 $ 605,803 Shares: Weighted average outstanding shares (denominator for basic calculation) 62,666 63,279 62,701 63,941 Equivalent shares from outstanding stock options 1,123 1,017 1,218 1,189 Denominator for diluted calculation 63,789 64,296 63,919 65,130 Earnings per share: Basic $ 4.19 $ 4.76 $ 10.13 $ 9.47 Diluted $ 4.12 $ 4.68 $ 9.93 $ 9.30
Schedule Of Earnings Per Share Basic And Diluted By Common Class [Text Block]	The following table presents approximate amounts of stock options and performance contingent shares excluded from the calculation of common equivalent shares (in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Excluded from common equivalent shares: Stock options 139 227 416 349 Performance contingent shares 258 276 182 256

Equity (Tables)

Equity (Tables)	9 Months Ended
	Sep. 30, 2019
Stockholders' Equity Note [Abstract]
Schedule of Stock by Class [Table Text Block]	The changes in the number of common stock issued, held in treasury and outstanding are as follows for the periods indicated: Issued Held In Treasury Outstanding Balance, December 31, 2018 79,137,758 16,323,390 62,814,368 Common stock acquired — 546,614 (546,614 ) Stock-based compensation (1) — (341,447 ) 341,447 Balance, September 30, 2019 79,137,758 16,528,557 62,609,201 Issued Held In Treasury Outstanding Balance, December 31, 2017 79,137,758 14,685,663 64,452,095 Common stock acquired — 1,750,295 (1,750,295 ) Stock-based compensation (1) — (249,068 ) 249,068 Balance, September 30, 2018 79,137,758 16,186,890 62,950,868 (1) Represents net shares issued from treasury pursuant to the Company’s equity-based compensation programs.
Components of Accumulated Other Comprehensive Income	The balance of and changes in each component of accumulated other comprehensive income (loss) (“AOCI”) for the nine months ended September 30, 2019 and 2018 are as follows (dollars in thousands): Accumulated Currency Translation Adjustments Unrealized Appreciation (Depreciation) of Investments (1) Pension and Postretirement Benefits Total Balance, December 31, 2018 $ (168,698 ) $ 856,159 $ (50,698 ) $ 636,763 Other comprehensive income (loss) before reclassifications 16,155 3,526,151 (11,735 ) 3,530,571 Amounts reclassified to (from) AOCI — (170,531 ) 3,728 (166,803 ) Deferred income tax benefit (expense) (4,631 ) (739,230 ) 1,676 (742,185 ) Balance, September 30, 2019 $ (157,174 ) $ 3,472,549 $ (57,029 ) $ 3,258,346 Accumulated Currency Translation Adjustments Unrealized Appreciation (Depreciation) of Investments (1) Pension and Postretirement Benefits Total Balance, December 31, 2017 $ (86,350 ) $ 2,200,661 $ (50,680 ) $ 2,063,631 Other comprehensive income (loss) before reclassifications (24,977 ) (1,638,146 ) (3,391 ) (1,666,514 ) Amounts reclassified to (from) AOCI — 79,505 3,986 83,491 Deferred income tax benefit (expense) (5,398 ) 340,332 (164 ) 334,770 Adoption of new accounting standard (2,573 ) — — (2,573 ) Balance, September 30, 2018 $ (119,298 ) $ 982,352 $ (50,249 ) $ 812,805 (1) Includes cash flow hedges of $(47,202) and $8,788 as of September 30, 2019 and December 31, 2018 , respectively, and $29,043 and $2,619 as of September 30, 2018 and December 31, 2017 , respectively. See Note 5 - “Derivative Instruments” for additional information on cash flow hedges.
Reclassification Out Of Accumulated Other Comprehensive Income	The following table presents the amounts of AOCI reclassifications for the three and nine months ended September 30, 2019 and 2018 (dollars in thousands): Amount Reclassified from AOCI Three months ended September 30, Nine months ended September 30, Details about AOCI Components 2019 2018 2019 2018 Affected Line Item in Statements of Income Net unrealized investment gains (losses): Net unrealized gains (losses) on available-for-sale securities $ 50,537 $ (21,249 ) $ 70,513 $ (60,347 ) Investment related gains (losses), net Cash flow hedges - Interest rate 255 234 1,107 (108 ) (1) Cash flow hedges - Currency/Interest rate (38 ) 50 (19 ) 270 (1) Deferred policy acquisition costs attributed to unrealized gains and losses 21,275 (4,893 ) 98,930 (19,320 ) (2) Total 72,029 (25,858 ) 170,531 (79,505 ) Provision for income taxes (14,808 ) 5,355 (35,087 ) 16,978 Net unrealized gains (losses), net of tax $ 57,221 $ (20,503 ) $ 135,444 $ (62,527 ) Amortization of defined benefit plan items: Prior service cost (credit) $ 267 $ 246 $ 804 $ 739 (3) Actuarial gains/(losses) (1,102 ) (1,866 ) (4,532 ) (4,725 ) (3) Total (835 ) (1,620 ) (3,728 ) (3,986 ) Provision for income taxes 175 340 783 837 Amortization of defined benefit plans, net of tax $ (660 ) $ (1,280 ) $ (2,945 ) $ (3,149 ) Total reclassifications for the period $ 56,561 $ (21,783 ) $ 132,499 $ (65,676 ) (1) See Note 5 - “Derivative Instruments” for additional information on cash flow hedges. (2) This AOCI component is included in the computation of the deferred policy acquisition cost. See Note 8 – “Deferred Policy Acquisition Costs” of the 2018 Annual Report for additional details. (3) This AOCI component is included in the computation of the net periodic pension cost. See Note 10 – “Employee Benefit Plans” for additional details.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2019
Investments [Abstract]
Available For Sale Securities	The following tables provide information relating to investments in fixed maturity securities by sector as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019: Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value % of Total Other-than- Available-for-sale: Corporate $ 28,154,301 $ 2,277,070 $ 78,152 $ 30,353,219 61.3 % $ — Canadian government 2,962,729 1,670,680 190 4,633,219 9.4 — RMBS 2,360,691 81,367 2,216 2,439,842 4.9 — ABS 2,809,008 27,621 13,994 2,822,635 5.7 275 CMBS 1,698,334 84,345 461 1,782,218 3.6 — U.S. government 1,570,540 98,193 228 1,668,505 3.4 — State and political subdivisions 1,078,019 113,684 1,600 1,190,103 2.4 — Other foreign government 4,226,819 370,109 5,402 4,591,526 9.3 — Total fixed maturity securities $ 44,860,441 $ 4,723,069 $ 102,243 $ 49,481,267 100.0 % $ 275 December 31, 2018: Amortized Cost Unrealized Gains Unrealized Losses Estimated Fair Value % of Total Other-than- Available-for-sale: Corporate $ 24,006,407 $ 530,804 $ 555,092 $ 23,982,119 59.9 % $ — Canadian government 2,768,466 1,126,227 2,308 3,892,385 9.7 — RMBS 1,872,236 22,267 25,282 1,869,221 4.7 — ABS 2,171,254 10,779 32,829 2,149,204 5.4 275 CMBS 1,428,115 9,153 18,234 1,419,034 3.5 — U.S. government 2,233,537 10,204 57,867 2,185,874 5.5 — State and political subdivisions 721,290 39,914 9,010 752,194 1.9 — Other foreign government 3,680,863 109,320 47,868 3,742,315 9.4 — Total fixed maturity securities $ 38,882,168 $ 1,858,668 $ 748,490 $ 39,992,346 100.0 % $ 275
Schedule of Financial Instruments Owned and Pledged as Collateral [Table Text Block]	The following table includes fixed maturity securities pledged and received as collateral and assets in trust held to satisfy collateral requirements under derivative transactions and certain third-party reinsurance treaties as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Fixed maturity securities pledged as collateral $ 95,387 $ 99,393 $ 80,891 $ 83,950 Fixed maturity securities received as collateral n/a 696,435 n/a 616,584 Assets in trust held to satisfy collateral requirements 26,332,915 28,368,125 20,072,735 20,366,170
Concentration Risk Disclosure [Text Block]	The Company’s exposure to concentrations of credit risk from single issuers greater than 10% of the Company’s stockholders’ equity included securities of the U.S. government and its agencies as well as the securities disclosed below as of September 30, 2019 and December 31, 2018 (dollars in thousands). September 30, 2019 December 31, 2018 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Fixed maturity securities guaranteed or issued by: Canadian province of Quebec $ 1,167,744 $ 2,153,434 $ 1,091,018 $ 1,757,087 Canadian province of Ontario 981,279 1,371,571 913,642 1,187,526
Investments Classified By Contractual Maturity Date	The amortized cost and estimated fair value of fixed maturity securities classified as available-for-sale at September 30, 2019 are shown by contractual maturity in the table below (dollars in thousands). Actual maturities can differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. Asset and mortgage-backed securities are shown separately in the table below, as they are not due at a single maturity date. Amortized Cost Estimated Fair Value Available-for-sale: Due in one year or less $ 1,538,152 $ 1,547,966 Due after one year through five years 8,318,044 8,656,979 Due after five years through ten years 9,485,912 10,275,538 Due after ten years 18,650,300 21,956,089 Asset and mortgage-backed securities 6,868,033 7,044,695 Total $ 44,860,441 $ 49,481,267
Fixed Maturity Holdings Industry Types Weighted Average Credit Ratings [Table Text Block]	The tables below show the major industry types of the Company’s corporate fixed maturity holdings as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019: Estimated Amortized Cost Fair Value % of Total Finance $ 10,604,290 $ 11,327,324 37.3 % Industrial 14,099,496 15,213,256 50.1 Utility 3,450,515 3,812,639 12.6 Total $ 28,154,301 $ 30,353,219 100.0 % December 31, 2018: Estimated Amortized Cost Fair Value % of Total Finance $ 8,793,742 $ 8,730,568 36.3 % Industrial 12,336,857 12,342,111 51.6 Utility 2,875,808 2,909,440 12.1 Total $ 24,006,407 $ 23,982,119 100.0 %
Investments In Debt And Equity Securities Gross Unrealized Losses Disclosures	The following table presents the total gross unrealized losses for the 856 and 3,109 fixed maturity securities as of September 30, 2019 and December 31, 2018, respectively, where the estimated fair value had declined and remained below amortized cost by the indicated amount (dollars in thousands): September 30, 2019 December 31, 2018 Gross Unrealized Losses % of Total Gross Unrealized Losses % of Total Less than 20% $ 75,658 74.0 % $ 721,015 96.3 % 20% or more for less than six months 10,064 9.8 21,336 2.9 20% or more for six months or greater 16,521 16.2 6,139 0.8 Total $ 102,243 100.0 % $ 748,490 100.0 %
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block]	The following tables present the estimated fair values and gross unrealized losses, including other-than-temporary impairment losses reported in AOCI, for 856 and 3,109 fixed maturity securities that have estimated fair values below amortized cost as of September 30, 2019 and December 31, 2018, respectively (dollars in thousands). These investments are presented by class and grade of security, as well as the length of time the related fair value has remained below amortized cost. Less than 12 months 12 months or greater Total Gross Gross Gross September 30, 2019: Estimated Unrealized Estimated Unrealized Estimated Unrealized Fair Value Losses Fair Value Losses Fair Value Losses Investment grade securities: Corporate $ 1,570,113 $ 25,598 $ 410,462 $ 11,576 $ 1,980,575 $ 37,174 Canadian government 867 10 17,509 180 18,376 190 RMBS 222,644 987 116,037 1,218 338,681 2,205 ABS 765,223 4,861 413,297 9,133 1,178,520 13,994 CMBS 48,699 218 32,638 232 81,337 450 U.S. government 2,758 7 65,220 221 67,978 228 State and political subdivisions 11,129 97 13,838 1,503 24,967 1,600 Other foreign government 198,170 3,474 45,430 761 243,600 4,235 Total investment grade securities 2,819,603 35,252 1,114,431 24,824 3,934,034 60,076 Below investment grade securities: Corporate 206,108 24,561 122,670 16,417 328,778 40,978 RMBS — — 939 11 939 11 CMBS 1,042 11 — — 1,042 11 Other foreign government 12,914 290 13,173 877 26,087 1,167 Total below investment grade securities 220,064 24,862 136,782 17,305 356,846 42,167 Total fixed maturity securities $ 3,039,667 $ 60,114 $ 1,251,213 $ 42,129 $ 4,290,880 $ 102,243 Less than 12 months 12 months or greater Total Gross Gross Gross December 31, 2018: Estimated Unrealized Estimated Unrealized Estimated Unrealized Fair Value Losses Fair Value Losses Fair Value Losses Investment grade securities: Corporate $ 8,505,371 $ 302,604 $ 3,611,266 $ 195,082 $ 12,116,637 $ 497,686 Canadian government 25,169 419 131,806 1,612 156,975 2,031 RMBS 269,558 2,488 836,741 22,760 1,106,299 25,248 ABS 1,102,677 24,271 381,609 8,523 1,484,286 32,794 CMBS 384,259 4,304 414,719 13,930 798,978 18,234 U.S. government 8,616 80 1,086,694 57,787 1,095,310 57,867 State and political subdivisions 103,504 1,538 157,330 7,472 260,834 9,010 Other foreign government 789,859 24,509 472,934 17,446 1,262,793 41,955 Total investment grade securities 11,189,013 360,213 7,093,099 324,612 18,282,112 684,825 Below investment grade securities: Corporate 755,679 42,760 122,559 14,646 878,238 57,406 Canadian government 443 34 1,770 243 2,213 277 RMBS — — 1,026 34 1,026 34 ABS — — 1,063 35 1,063 35 Other foreign government 128,725 5,574 7,479 339 136,204 5,913 Total below investment grade securities 884,847 48,368 133,897 15,297 1,018,744 63,665 Total fixed maturity securities $ 12,073,860 $ 408,581 $ 7,226,996 $ 339,909 $ 19,300,856 $ 748,490
Investment Income	Major categories of investment income, net of related expenses, consist of the following (dollars in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Fixed maturity securities available-for-sale $ 464,431 $ 378,669 $ 1,307,359 $ 1,121,496 Equity securities 1,709 1,319 3,600 3,710 Mortgage loans on real estate 67,071 54,424 187,142 155,083 Policy loans 14,580 14,730 43,083 44,285 Funds withheld at interest 81,862 108,232 209,568 270,094 Short-term investments and cash and cash equivalents 6,152 3,067 20,517 9,276 Other invested assets 66,611 35,594 140,757 80,207 Investment income 702,416 596,035 1,912,026 1,684,151 Investment expense (23,611 ) (23,293 ) (69,266 ) (67,019 ) Investment income, net of related expenses $ 678,805 $ 572,742 $ 1,842,760 $ 1,617,132
Gain Loss On Investments	Investment related gains (losses), net, consist of the following (dollars in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Fixed maturity securities available-for-sale: Other-than-temporary impairment losses $ (8,539 ) $ (10,705 ) $ (17,992 ) $ (14,055 ) Gain on investment activity 67,980 20,040 116,409 52,146 Loss on investment activity (12,996 ) (37,880 ) (38,589 ) (94,194 ) Equity securities: Gain on investment activity 432 3,932 506 4,429 Loss on investment activity — (174 ) (1 ) (1,124 ) Change in unrealized gains (losses) recognized in earnings 3,396 3,539 9,813 (7,564 ) Other impairment losses and change in mortgage loan provision (4,030 ) (6,566 ) (11,498 ) (8,235 ) Derivatives and other, net 2,541 7,797 10,396 37,538 Total investment related gains (losses), net $ 48,784 $ (20,017 ) $ 69,044 $ (31,059 )
Schedule of Repurchase Agreements [Table Text Block]	The following table includes the amount of borrowed securities, securities lent and securities collateral received as part of the securities lending program and repurchased/reverse repurchased securities pledged and received as of September 30, 2019 and December 31, 2018 (dollars in thousands). September 30, 2019 December 31, 2018 Amortized Cost Estimated Fair Value Amortized Cost Estimated Fair Value Borrowed securities $ 335,408 $ 372,617 $ 335,781 $ 366,663 Securities lending: Securities loaned 97,606 104,191 101,981 102,618 Securities received n/a 107,000 n/a 112,000 Repurchase program/reverse repurchase program: Securities pledged 610,701 644,471 554,806 554,589 Securities received n/a 624,348 n/a 530,932
Schedule of Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets [Table Text Block]	The following tables present information on the Company’s securities lending and repurchase transactions as of September 30, 2019 and December 31, 2018 , respectively (dollars in thousands). Collateral associated with certain borrowed securities is not included within the table, as the collateral pledged to each counterparty is the right to reinsurance treaty cash flows. September 30, 2019 Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days Total Securities lending transactions: Corporate $ — $ — $ — $ 104,191 $ 104,191 Total — — — 104,191 104,191 Repurchase transactions: Corporate — — — 324,033 324,033 U.S. government — — 66,264 142,124 208,388 Foreign government — — — 112,050 112,050 Other — — — — — Total — — 66,264 578,207 644,471 Total borrowings $ — $ — $ 66,264 $ 682,398 $ 748,662 Gross amount of recognized liabilities for securities lending and repurchase transactions in preceding table $ 758,883 Amounts related to agreements not included in offsetting disclosure $ 10,221 December 31, 2018 Remaining Contractual Maturity of the Agreements Overnight and Continuous Up to 30 Days 30-90 Days Greater than 90 Days Total Securities lending transactions: Corporate $ — $ — $ — $ 102,618 $ 102,618 Total $ — $ — $ — $ 102,618 $ 102,618 Repurchase transactions: Corporate $ — $ — $ — $ 254,151 $ 254,151 U.S. government — — — 221,572 221,572 Foreign government — — — 78,866 78,866 Total — — — 554,589 554,589 Total borrowings $ — $ — $ — $ 657,207 $ 657,207 Gross amount of recognized liabilities for securities lending and repurchase transactions in preceding table $ 671,492 Amounts related to agreements not included in offsetting disclosure $ 14,285
Disclosure Of Real Estate Holdings By Property Type [Table Text Block]	The distribution of mortgage loans by property type is as follows as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Property type: Carrying Value % of Total Carrying Value % of Total Office building $ 1,787,871 31.6 % $ 1,725,748 34.6 % Retail 1,645,521 29.0 1,432,394 28.7 Industrial 1,137,598 20.1 961,924 19.3 Apartment 748,392 13.2 571,291 11.5 Other commercial 347,972 6.1 291,997 5.9 Recorded investment 5,667,354 100.0 % 4,983,354 100.0 % Unamortized balance of loan origination fees and expenses (8,314 ) (5,770 ) Valuation allowances (11,775 ) (11,286 ) Total mortgage loans on real estate $ 5,647,265 $ 4,966,298
Mortgage Loans Classified By Contractual Maturity Date [Table Text Block]	The maturities of mortgage loans as of September 30, 2019 and December 31, 2018 are as follows (dollars in thousands): September 30, 2019 December 31, 2018 Recorded Investment % of Total Recorded Investment % of Total Due within five years $ 1,750,771 30.9 % $ 1,425,598 28.6 % Due after five years through ten years 3,001,527 53.0 2,686,264 53.9 Due after ten years 915,056 16.1 871,492 17.5 Total $ 5,667,354 100.0 % $ 4,983,354 100.0 %
Financing Receivable Credit Quality Indicators [Table Text Block]	The following tables set forth certain key credit quality indicators of the Company’s recorded investment in mortgage loans as of September 30, 2019 and December 31, 2018 (dollars in thousands): Recorded Investment Debt Service Ratios Construction Loans >1.20x 1.00x - 1.20x <1.00x Total % of Total September 30, 2019: Loan-to-Value Ratio 0% - 59.99% $ 2,912,673 $ 91,954 $ 12,932 $ 21,434 $ 3,038,993 53.6 % 60% - 69.99% 1,889,981 83,814 37,321 — 2,011,116 35.5 70% - 79.99% 395,599 — 32,586 — 428,185 7.6 Greater than 80% 116,605 49,087 23,368 — 189,060 3.3 Total $ 5,314,858 $ 224,855 $ 106,207 $ 21,434 $ 5,667,354 100.0 % Recorded Investment Debt Service Ratios Construction Loans >1.20x 1.00x - 1.20x <1.00x Total % of Total December 31, 2018: Loan-to-Value Ratio 0% - 59.99% $ 2,410,556 $ 61,246 $ 38,177 $ 13,691 $ 2,523,670 50.6 % 60% - 69.99% 1,618,374 73,908 38,120 18,929 1,749,331 35.1 70% - 79.99% 414,269 48,438 54,440 — 517,147 10.4 Greater than 80% 117,978 49,668 25,560 — 193,206 3.9 Total $ 4,561,177 $ 233,260 $ 156,297 $ 32,620 $ 4,983,354 100.0 %
Financing Receivable, Past Due [Table Text Block]	The age analysis of the Company’s past due recorded investments in mortgage loans as of September 30, 2019 and December 31, 2018 is as follows (dollars in thousands): September 30, 2019 December 31, 2018 31-60 days past due $ 21,065 $ — Total past due 21,065 — Current 5,646,289 4,983,354 Total $ 5,667,354 $ 4,983,354
Recorded Investment And Allowance For Credit Losses	The following table presents the recorded investment in mortgage loans, by method of measuring impairment, and the related valuation allowances as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Mortgage loans: Individually measured for impairment $ 17,016 $ 30,635 Collectively measured for impairment 5,650,338 4,952,719 Recorded investment $ 5,667,354 $ 4,983,354 Valuation allowances: Individually measured for impairment $ — $ — Collectively measured for impairment 11,775 11,286 Total valuation allowances $ 11,775 $ 11,286
Allowance For Mortgage Loan And Lease Losses Provision For Loss Net	Information regarding the Company’s loan valuation allowances for mortgage loans for the three and nine months ended September 30, 2019 and 2018 is as follows (dollars in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Balance, beginning of period $ 11,692 $ 9,706 $ 11,286 $ 9,384 Provision (release) 88 656 485 986 Translation adjustment (5 ) 4 4 (4 ) Balance, end of period $ 11,775 $ 10,366 $ 11,775 $ 10,366
Impaired Financing Receivables Table	Information regarding the portion of the Company’s mortgage loans that were impaired as of September 30, 2019 and December 31, 2018 is as follows (dollars in thousands): Unpaid Principal Balance Recorded Investment Related Allowance Carrying Value September 30, 2019: Impaired mortgage loans with no valuation allowance recorded $ 17,017 $ 17,016 $ — $ 17,016 Impaired mortgage loans with valuation allowance recorded — — — — Total impaired mortgage loans $ 17,017 $ 17,016 $ — $ 17,016 December 31, 2018: Impaired mortgage loans with no valuation allowance recorded $ 30,660 $ 30,635 $ — $ 30,635 Impaired mortgage loans with valuation allowance recorded — — — — Total impaired mortgage loans $ 30,660 $ 30,635 $ — $ 30,635 The Company’s average investment balance of impaired mortgage loans and the related interest income are reflected in the table below for the periods indicated (dollars in thousands): Three months ended September 30, 2019 2018 Average (1) Interest Income Average Recorded Investment (1) Interest Income Impaired mortgage loans with no valuation allowance recorded $ 17,015 $ 170 $ 30,641 $ 346 Impaired mortgage loans with valuation allowance recorded — — — — Total impaired mortgage loans $ 17,015 $ 170 $ 30,641 $ 346 Nine months ended September 30, 2019 2018 Average (1) Interest Income Average (1) Interest Income Impaired mortgage loans with no valuation allowance recorded $ 20,436 $ 669 $ 22,641 $ 650 Impaired mortgage loans with valuation allowance recorded — — — — Total impaired mortgage loans $ 20,436 $ 669 $ 22,641 $ 650 (1) Average recorded investment represents the average loan balances as of the beginning of period and all subsequent quarterly end of period balances.
Schedule Of Other Invested Assets [Table Text Block]	Carrying values of these assets as of September 30, 2019 and December 31, 2018 were as follows (dollars in thousands): September 30, 2019 December 31, 2018 Limited partnership interests and real estate joint ventures $ 1,059,025 $ 965,094 Lifetime mortgages 669,981 475,905 Derivatives 142,099 180,699 FVO contractholder-directed unit-linked investments 252,277 197,770 Other 91,893 95,829 Total other invested assets $ 2,215,275 $ 1,915,297

Derivative Instruments (Tables)

Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule Of Derivative Instruments In Statement Of Financial Position Fair Value	The following table presents the notional amounts and gross fair value of derivative instruments prior to taking into account the netting effects of master netting agreements as of September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Primary Underlying Risk Notional Carrying Value/Fair Value Notional Carrying Value/Fair Value Amount Assets Liabilities Amount Assets Liabilities Derivatives not designated as hedging instruments: Interest rate swaps Interest rate $ 929,963 $ 84,306 $ 2,778 $ 1,040,588 $ 47,652 $ 961 Financial futures Equity 361,030 — — 325,620 — — Foreign currency swaps Foreign currency 149,698 — 12,454 149,698 504 4,659 Foreign currency forwards Foreign currency 125,000 337 — 25,000 — 234 Consumer price index swaps CPI 422,068 360 33,245 385,580 — 11,384 Credit default swaps Credit 1,337,800 5,888 139 1,338,300 6,003 1,166 Equity options Equity 386,536 24,844 — 439,158 42,836 — Longevity swaps Longevity 871,920 51,620 — 917,360 47,789 — Mortality swaps Mortality 25,000 — 853 25,000 — 369 Synthetic guaranteed investment contracts Interest rate 13,919,866 — — 13,397,729 — — Embedded derivatives in: Modified coinsurance or funds withheld arrangements — 121,275 — — 109,597 — Indexed annuity products — — 779,128 — — 776,940 Variable annuity products — — 210,041 — — 167,925 Total non-hedging derivatives 18,528,881 288,630 1,038,638 18,044,033 254,381 963,638 Derivatives designated as hedging instruments: Interest rate swaps Foreign currency/Interest rate 435,000 — 34,467 435,000 — 27,257 Foreign currency swaps Foreign currency 366,193 26,384 7,615 494,461 51,311 — Foreign currency forwards Foreign currency 1,025,548 43,441 — 911,197 50,974 — Total hedging derivatives 1,826,741 69,825 42,082 1,840,658 102,285 27,257 Total derivatives $ 20,355,622 $ 358,455 $ 1,080,720 $ 19,884,691 $ 356,666 $ 990,895
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The gain or loss on the hedged item attributable to a change in foreign currency and the offsetting gain or loss on the related foreign currency swaps as of September 30, 2019 and 2018, were (dollars in thousands): Type of Fair Value Hedge Hedged Item Gains (Losses) Recognized for Derivatives Gains (Losses) Recognized for Hedged Items Investment Related Gains (Losses) For the three months ended September 30, 2019: Foreign currency swaps Foreign-denominated fixed maturity securities $ (5,995 ) $ 4,088 For the three months ended September 30, 2018: Foreign currency swaps Foreign-denominated fixed maturity securities $ (2,258 ) $ 2,832 For the nine months ended September 30, 2019: Foreign currency swaps Foreign-denominated fixed maturity securities $ (10,422 ) $ 4,503 For the nine months ended September 30, 2018: Foreign currency swaps Foreign-denominated fixed maturity securities $ (5,284 ) $ 9,666
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table presents the components of AOCI, before income tax, and the condensed consolidated income statement classification where the gain or loss is recognized related to cash flow hedges for the three and nine months ended September 30, 2019 and 2018 (dollars in thousands): Three months ended September 30, 2019 2018 Balance beginning of period $ (14,862 ) $ 22,656 Gains (losses) deferred in other comprehensive income (loss) (32,123 ) 6,671 Amounts reclassified to investment income 38 (50 ) Amounts reclassified to interest expense (255 ) (234 ) Balance end of period $ (47,202 ) $ 29,043 Nine months ended September 30, 2019 2018 Balance beginning of period $ 8,788 $ 2,619 Gains (losses) deferred in other comprehensive income (loss) (54,902 ) 26,586 Amounts reclassified to investment income 19 (270 ) Amounts reclassified to interest expense (1,107 ) 108 Balance end of period $ (47,202 ) $ 29,043
Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following table presents the effect of derivatives in cash flow hedging relationships on the condensed consolidated statements of income and the condensed consolidated statements of comprehensive income for the three and nine months ended September 30, 2019 and 2018 (dollars in thousands): Derivative Type Gain (Loss) Deferred in AOCI Gain (Loss) Reclassified into Income from AOCI Investment Income Interest Expense For the three months ended September 30, 2019: Interest rate $ (24,846 ) $ — $ 255 Currency/Interest rate (7,277 ) (38 ) — Total $ (32,123 ) $ (38 ) $ 255 For the three months ended September 30, 2018: Interest rate $ 7,490 $ — $ 234 Currency/Interest rate (819 ) 50 — Total $ 6,671 $ 50 $ 234 For the nine months ended September 30, 2019: Interest rate $ (46,816 ) $ — $ 1,107 Currency/Interest rate (8,086 ) (19 ) — Total $ (54,902 ) $ (19 ) $ 1,107 For the nine months ended September 30, 2018: Interest rate $ 27,217 $ — $ (108 ) Currency/Interest rate (631 ) 270 — Total $ 26,586 $ 270 $ (108 )
Schedule of Net Investment Hedges, Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following table illustrates the Company’s net investments in foreign operations (“NIFO”) hedges for the three and nine months ended September 30, 2019 and 2018 (dollars in thousands): Derivative Gains (Losses) Deferred in AOCI For the three months ended September 30, For the nine months ended September 30, Type of NIFO Hedge (1) 2019 2018 2019 2018 Foreign currency swaps $ 3,930 $ (5,877 ) $ (5,563 ) $ 11,125 Foreign currency forwards 16,427 (11,562 ) (7,669 ) 11,737 Total $ 20,357 $ (17,439 ) $ (13,232 ) $ 22,862 (1) There were no sales or substantial liquidations of net investments in foreign operations that would have required the reclassification of gains or losses from accumulated other comprehensive income (loss) into investment income during the periods presented.
Derivatives Not Designated as Hedging Instruments [Table Text Block]	A summary of the effect of non-hedging derivatives, including embedded derivatives, on the Company’s condensed consolidated statements of income for the three and nine months ended September 30, 2019 and 2018 is as follows (dollars in thousands): Gain (Loss) for the three months ended September 30, Type of Non-hedging Derivative Income Statement Location of Gain (Loss) 2019 2018 Interest rate swaps Investment related gains (losses), net $ 38,701 $ (12,228 ) Financial futures Investment related gains (losses), net 322 (6,544 ) Foreign currency swaps Investment related gains (losses), net 867 — Foreign currency forwards Investment related gains (losses), net 337 (58 ) CPI swaps Investment related gains (losses), net (8,235 ) (4,223 ) Credit default swaps Investment related gains (losses), net 1,961 4,689 Equity options Investment related gains (losses), net 243 (9,793 ) Longevity swaps Other revenues 2,063 2,426 Mortality swaps Other revenues — 473 Subtotal 36,259 (25,258 ) Embedded derivatives in: Modified coinsurance or funds withheld arrangements Investment related gains (losses), net 8,508 (2,081 ) Indexed annuity products Interest credited (44,972 ) (25,347 ) Variable annuity products Investment related gains (losses), net (42,233 ) 32,133 Total non-hedging derivatives $ (42,438 ) $ (20,553 ) Gain (Loss) for the nine months ended September 30, Type of Non-hedging Derivative Income Statement Location of Gain (Loss) 2019 2018 Interest rate swaps Investment related gains (losses), net $ 96,079 $ (47,399 ) Financial futures Investment related gains (losses), net (29,641 ) (7,312 ) Foreign currency swaps Investment related gains (losses), net (4,790 ) — Foreign currency forwards Investment related gains (losses), net 571 3 CPI swaps Investment related gains (losses), net (23,898 ) (996 ) Credit default swaps Investment related gains (losses), net 21,539 5,371 Equity options Investment related gains (losses), net (27,269 ) (15,207 ) Longevity swaps Other revenues 6,390 6,983 Mortality swaps Other revenues (484 ) (326 ) Subtotal 38,497 (58,883 ) Embedded derivatives in: Modified coinsurance or funds withheld arrangements Investment related gains (losses), net 11,678 20,335 Indexed annuity products Interest credited (50,361 ) 6,523 Variable annuity products Investment related gains (losses), net (42,116 ) 62,242 Total non-hedging derivatives $ (42,302 ) $ 30,217
Disclosure of Credit Derivatives [Table Text Block]	The following table presents the estimated fair value, maximum amount of future payments and weighted average years to maturity of credit default swaps sold by the Company at September 30, 2019 and December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Rating Agency Designation of Referenced Credit Obligations (1) Estimated Fair Value of Credit Default Swaps Maximum Amount of Future Payments under Credit Default Swaps (2) Weighted Average Years to Maturity (3) Estimated Fair Value of Credit Default Swaps Maximum Amount of Future Payments under Credit Default Swaps (2) Weighted Average Years to Maturity (3) AAA/AA+/AA/AA-/A+/A/A- Single name credit default swaps $ 1,018 $ 117,500 1.6 $ 1,953 $ 152,000 2.2 Credit default swaps referencing indices 342 240,000 10.2 — — 0.0 Subtotal 1,360 357,500 7.4 1,953 152,000 2.2 BBB+/BBB/BBB- Single name credit default swaps 4,103 337,700 2.0 2,930 353,700 2.2 Credit default swaps referencing indices 111 632,600 2.9 (76 ) 817,600 6.4 Subtotal 4,214 970,300 2.6 2,854 1,171,300 5.1 BB+/BB/BB- Single name credit default swaps 175 10,000 2.7 30 15,000 0.7 Subtotal 175 10,000 2.7 30 15,000 0.7 Total $ 5,749 $ 1,337,800 3.9 $ 4,837 $ 1,338,300 4.7 (1) The rating agency designations are based on ratings from Standard and Poor’s (“S&P”). (2) Assumes the value of the referenced credit obligations is zero. (3) The weighted average years to maturity of the credit default swaps is calculated based on weighted average notional amounts.
Offsetting Assets [Table Text Block]	The following table provides information relating to the Company’s derivative instruments as of September 30, 2019 and December 31, 2018 (dollars in thousands): Gross Amounts Not Offset in the Balance Sheet Gross Amounts Recognized Gross Amounts Offset in the Balance Sheet Net Amounts Presented in the Balance Sheet Financial Instruments (1) Cash Collateral Pledged/ Received Net Amount September 30, 2019: Derivative assets $ 237,180 $ (43,461 ) $ 193,719 $ — $ (205,890 ) $ (12,171 ) Derivative liabilities 91,551 (43,461 ) 48,090 (81,090 ) (60,080 ) (93,080 ) December 31, 2018: Derivative assets $ 247,069 $ (18,581 ) $ 228,488 $ — $ (235,611 ) $ (7,123 ) Derivative liabilities 46,030 (18,581 ) 27,449 (71,376 ) (24,080 ) (68,007 ) (1) Includes initial margin posted to a central clearing partner.
Offsetting Liabilities [Table Text Block]	The following table provides information relating to the Company’s derivative instruments as of September 30, 2019 and December 31, 2018 (dollars in thousands): Gross Amounts Not Offset in the Balance Sheet Gross Amounts Recognized Gross Amounts Offset in the Balance Sheet Net Amounts Presented in the Balance Sheet Financial Instruments (1) Cash Collateral Pledged/ Received Net Amount September 30, 2019: Derivative assets $ 237,180 $ (43,461 ) $ 193,719 $ — $ (205,890 ) $ (12,171 ) Derivative liabilities 91,551 (43,461 ) 48,090 (81,090 ) (60,080 ) (93,080 ) December 31, 2018: Derivative assets $ 247,069 $ (18,581 ) $ 228,488 $ — $ (235,611 ) $ (7,123 ) Derivative liabilities 46,030 (18,581 ) 27,449 (71,376 ) (24,080 ) (68,007 ) (1) Includes initial margin posted to a central clearing partner.

Fair Value of Assets and Liab_2

Fair Value of Assets and Liabilities Fair Value of Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Schedule Of Fair Value Assets and Liabilities Measured on Recurring Basis Table Text Block	Assets and liabilities measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018 are summarized below (dollars in thousands): September 30, 2019: Fair Value Measurements Using: Total Level 1 Level 2 Level 3 Assets: Fixed maturity securities – available-for-sale: Corporate $ 30,353,219 $ — $ 28,547,959 $ 1,805,260 Canadian government 4,633,219 — 3,942,376 690,843 RMBS 2,439,842 — 2,416,762 23,080 ABS 2,822,635 — 2,719,526 103,109 CMBS 1,782,218 — 1,752,250 29,968 U.S. government 1,668,505 1,541,294 110,070 17,141 State and political subdivisions 1,190,103 — 1,180,150 9,953 Other foreign government 4,591,526 — 4,575,383 16,143 Total fixed maturity securities – available-for-sale 49,481,267 1,541,294 45,244,476 2,695,497 Equity securities 134,453 86,968 — 47,485 Funds withheld at interest – embedded derivatives 121,275 — — 121,275 Cash equivalents 927,175 922,291 4,884 — Short-term investments 89,130 17,375 68,898 2,857 Other invested assets: Derivatives: Interest rate swaps 73,085 — 73,085 — Foreign currency forwards 43,654 — 43,654 — Credit default swaps (7,174 ) — (7,174 ) — Equity options 6,150 — 6,150 — Foreign currency swaps 26,384 — 26,384 — FVO contractholder-directed unit-linked investments 252,277 197,195 55,082 — Total other invested assets 394,376 197,195 197,181 — Other assets - longevity swaps 51,620 — — 51,620 Total $ 51,199,296 $ 2,765,123 $ 45,515,439 $ 2,918,734 Liabilities: Interest sensitive contract liabilities – embedded derivatives $ 989,170 $ — $ — $ 989,170 Other liabilities: Derivatives: Interest rate swaps 26,024 — 26,024 — Foreign currency swaps - non-hedged 12,454 — 12,454 — Foreign currency forwards (124 ) — (124 ) — CPI swaps 32,885 — 32,885 — Credit default swaps (12,923 ) — (12,923 ) — Equity options (18,694 ) — (18,694 ) — Foreign currency swaps 7,615 — 7,615 — Mortality swaps 853 — — 853 Total $ 1,037,260 $ — $ 47,237 $ 990,023 December 31, 2018: Fair Value Measurements Using: Total Level 1 Level 2 Level 3 Assets: Fixed maturity securities – available-for-sale: Corporate $ 23,982,119 $ — $ 22,651,194 $ 1,330,925 Canadian government 3,892,385 — 3,364,261 528,124 RMBS 1,869,221 — 1,862,366 6,855 ABS 2,149,204 — 2,053,632 95,572 CMBS 1,419,034 — 1,419,012 22 U.S. government 2,185,874 2,067,529 100,320 18,025 State and political subdivisions 752,194 — 741,992 10,202 Other foreign government 3,742,315 — 3,737,309 5,006 Total fixed maturity securities – available-for-sale 39,992,346 2,067,529 35,930,086 1,994,731 Equity securities 82,197 48,737 — 33,460 Funds withheld at interest – embedded derivatives 109,597 — — 109,597 Cash equivalents 485,167 473,509 11,658 — Short-term investments 105,991 4,989 98,774 2,228 Other invested assets: Derivatives: Interest rate swaps 37,976 — 37,976 — Foreign currency forwards 50,740 — 50,740 — Credit default swaps 4,466 — 4,466 — Equity options 36,206 — 36,206 — Foreign currency swaps 51,311 — 51,311 — FVO contractholder-directed unit-linked investments 197,770 196,781 989 — Total other invested assets 378,469 196,781 181,688 — Other assets - longevity swaps 47,789 — — 47,789 Total $ 41,201,556 $ 2,791,545 $ 36,222,206 $ 2,187,805 Liabilities: Interest sensitive contract liabilities – embedded derivatives $ 944,865 $ — $ — $ 944,865 Other liabilities: Derivatives: Interest rate swaps 18,542 — 18,542 — Foreign currency swaps - non-hedged 4,155 — 4,155 — CPI swaps 11,384 — 11,384 — Credit default swaps (371 ) — (371 ) — Equity options (6,630 ) — (6,630 ) — Mortality swaps 369 — — 369 Total $ 972,314 $ — $ 27,080 $ 945,234
Fair Value Inputs, Liabilities, Quantitative Information [Table Text Block]	The following table presents quantitative information about significant unobservable inputs used in Level 3 fair value measurements that are developed internally by the Company as of September 30, 2019 and December 31, 2018 (dollars in thousands): Estimated Fair Value Valuation Technique Unobservable Inputs Range (Weighted Average) September 30, 2019 December 31, 2018 September 30, 2019 December 31, 2018 Assets: Corporate $ 888,946 $ 642,647 Market comparable securities Liquidity premium 0-5% (1%) 0-5% (1%) EBITDA Multiple 5.2x-6.1x (5.8x) 5.9x-7.5x (6.5x) ABS 102,027 77,842 Market comparable securities Liquidity premium 0-4% (1%) 0-1% (1%) U.S. government 17,141 18,025 Market comparable securities Liquidity premium 0-1% (1%) 0-1% (1%) Other foreign government 16,143 5,006 Market comparable securities Liquidity premium 0-1% (1%) 1 % Equity securities 30,681 25,007 Market comparable securities Liquidity premium 4 % 4 % EBITDA Multiple 6.9x-9.3x (7.9x) 6.9x-12.3x (7.9x) Funds withheld at interest- embedded derivatives 121,275 109,597 Total return swap Mortality 0-100% (2%) 0-100% (2%) Lapse 0-35% (12%) 0-35% (10%) Withdrawal 0-5% (3%) 0-5% (3%) CVA 0-5% (1%) 0-5% (1%) Crediting rate 2-4% (2%) 2-4% (2%) Longevity swaps 51,620 47,789 Discounted cash flow Mortality 0-100% (2%) 0-100% (2%) Mortality improvement (10%)-10% (3%) (10%)-10% (3%) Liabilities: Interest sensitive contract liabilities- embedded derivatives- indexed annuities 779,128 776,940 Discounted cash flow Mortality 0-100% (2%) 0-100% (2%) Lapse 0-35% (12%) 0-35% (10%) Withdrawal 0-5% (3%) 0-5% (3%) Option budget projection 2-4% (2%) 2-4% (2%) Interest sensitive contract liabilities- embedded derivatives- variable annuities 210,041 167,925 Discounted cash flow Mortality 0-100% (1%) 0-100% (1%) Lapse 0-25% (5%) 0-25% (5%) Withdrawal 0-7% (5%) 0-7% (5%) CVA 0-5% (1%) 0-5% (1%) Long-term volatility 0-27% (12%) 0-27% (13%) Mortality swaps 853 369 Discounted cash flow Mortality 0-100% (1%) 0-100% (1%)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The reconciliations for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) are as follows (dollars in thousands): For the three months ended September 30, 2019: Fixed maturity securities - available-for-sale Corporate Canadian government RMBS ABS Fair value, beginning of period $ 1,644,364 $ 671,027 $ 16,032 $ 110,322 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses 318 3,713 (113 ) 3 Included in other comprehensive income 17,090 16,103 150 (51 ) Purchases (1) 214,025 — — 10,764 Sales (1) (34,363 ) — — — Settlements (1) (63,216 ) — (2,370 ) (17,929 ) Transfers into Level 3 27,042 — 15,421 — Transfers out of Level 3 — — (6,040 ) — Fair value, end of period $ 1,805,260 $ 690,843 $ 23,080 $ 103,109 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ 344 $ 3,713 $ (113 ) $ 3 For the three months ended September 30, 2019 (continued): Fixed maturity securities available-for-sale CMBS U.S. government State Other foreign government Equity securities Fair value, beginning of period $ 19 $ 17,406 $ 9,855 $ 15,686 $ 44,807 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — (90 ) 6 — — Investment related gains (losses), net — — — — 2,737 Included in other comprehensive income (975 ) 79 132 457 — Purchases (1) 1,155 104 — — 821 Sales (1) — — — — (880 ) Settlements (1) (3 ) (358 ) (40 ) — — Transfers into Level 3 29,772 — — — — Fair value, end of period $ 29,968 $ 17,141 $ 9,953 $ 16,143 $ 47,485 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ (90 ) $ 6 $ — $ — Investment related gains (losses), net — — — — 2,638 For the three months ended September 30, 2019 (continued): Funds withheld at interest- embedded derivatives Short-term Investments Other assets - longevity swaps Interest sensitive contract liabilities embedded derivatives Other liabilities - mortality swaps Fair value, beginning of period $ 112,767 $ 28,387 $ 51,755 $ (908,491 ) $ (853 ) Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — 133 — — — Investment related gains (losses), net 8,508 — — (42,233 ) — Interest credited — — — (44,972 ) — Included in other comprehensive income — (266 ) (2,198 ) — — Other revenues — — 2,063 — — Purchases (1) — 1,656 — (16,887 ) — Sales (1) — — — — — Settlements (1) — (11 ) — 23,413 — Transfers out of Level 3 — (27,042 ) — — — Fair value, end of period $ 121,275 $ 2,857 $ 51,620 $ (989,170 ) $ (853 ) Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ 133 $ — $ — $ — Investment related gains (losses), net 8,508 — — (44,965 ) — Other revenues — — 2,063 — — Interest credited — — — (68,385 ) — For the nine months ended September 30, 2019: Fixed maturity securities - available-for-sale Corporate Canadian government RMBS ABS Fair value, beginning of period $ 1,330,925 $ 528,124 $ 6,855 $ 95,572 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses 478 10,775 (132 ) 25 Investment related gains (losses), net 15 — — 110 Included in other comprehensive income 53,222 151,944 221 1,972 Purchases (1) 604,897 — 3,018 50,511 Sales (1) (59,000 ) — — — Settlements (1) (166,865 ) — (3,945 ) (45,081 ) Transfers into Level 3 43,083 — 23,103 — Transfers out of Level 3 (1,495 ) — (6,040 ) — Fair value, end of period $ 1,805,260 $ 690,843 $ 23,080 $ 103,109 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ 580 $ 10,775 $ (132 ) $ 24 For the nine months ended September 30, 2019 (continued): Fixed maturity securities available-for-sale CMBS U.S. government State Other foreign government Equity securities Fair value, beginning of period $ 22 $ 18,025 $ 10,202 $ 5,006 $ 33,460 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — (265 ) 16 — — Investment related gains (losses), net — — — — 8,284 Included in other comprehensive income (975 ) 668 164 1,137 — Purchases (1) 1,155 290 — 10,000 6,621 Sales (1) — — — — (880 ) Settlements (1) (6 ) (1,577 ) (429 ) — — Transfers into Level 3 29,772 — — — — Fair value, end of period $ 29,968 $ 17,141 $ 9,953 $ 16,143 $ 47,485 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ (265 ) $ 16 $ — $ — Investment related gains (losses), net — — — — 8,185 For the nine months ended September 30, 2019 (continued): Funds withheld at interest- embedded derivatives Cash equivalents Short-term Investments Other assets - longevity swaps Interest sensitive contract liabilities embedded derivatives Other liabilities - mortality swaps Fair value, beginning of period $ 109,597 $ — $ 2,228 $ 47,789 $ (944,865 ) $ (369 ) Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — — 221 — — — Investment related gains (losses), net 11,678 — 17 — (42,116 ) — Interest credited — — — — (50,361 ) — Included in other comprehensive income — — (134 ) (2,559 ) — — Other revenues — — — 6,390 — (484 ) Purchases (1) — 19 29,664 — (12,904 ) — Sales (1) — — (1,517 ) — — — Settlements (1) — — (558 ) — 61,076 — Transfers out of Level 3 — (19 ) (27,064 ) — — — Fair value, end of period $ 121,275 $ — $ 2,857 $ 51,620 $ (989,170 ) $ (853 ) Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ — $ 221 $ — $ — $ — Investment related gains (losses), net 11,678 — — — (48,041 ) — Other revenues — — — 6,390 — (484 ) Interest credited — — — — (111,436 ) — For the three months ended September 30, 2018: Fixed maturity securities - available-for-sale Corporate Canadian government RMBS ABS Fair value, beginning of period $ 1,367,154 $ 572,698 $ 54,839 $ 70,686 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses (156 ) 3,520 3 20 Investment related gains (losses), net 239 — — 626 Included in other comprehensive income (4,858 ) (27,476 ) (1 ) (130 ) Purchases (1) 123,808 — — 11,099 Sales (1) (62,047 ) — — (462 ) Settlements (1) (101,868 ) — (3 ) (24,166 ) Transfers into Level 3 2,782 — — 64,009 Transfers out of Level 3 (69,119 ) — (54,838 ) (38,915 ) Fair value, end of period $ 1,255,935 $ 548,742 $ — $ 82,767 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ (180 ) $ 3,520 $ — $ 13 Investment related gains (losses), net (1,430 ) — — — For the three months ended September 30, 2018 (continued): Fixed maturity securities available-for-sale CMBS U.S. government State Other foreign government Fair value, beginning of period $ 1,867 $ 20,735 $ 16,505 $ 5,044 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — (107 ) 6 — Included in other comprehensive income 7 (122 ) (544 ) (32 ) Purchases (1) — 120 — — Settlements (1) (1 ) (374 ) (37 ) — Transfers into Level 3 1,752 — 9,859 — Transfers out of Level 3 (1,843 ) — (12,144 ) — Fair value, end of period $ 1,782 $ 20,252 $ 13,645 $ 5,012 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ (107 ) $ 6 $ — For the three months ended September 30, 2018 (continued): Equity securities Funds withheld at interest- embedded derivatives Short-term Investments Other assets - longevity swaps Interest sensitive contract liabilities embedded derivatives Other liabilities - mortality swaps Fair value, beginning of period $ 42,937 $ 144,610 $ 3,217 $ 43,971 $ (928,797 ) $ (782 ) Total gains/losses (realized/unrealized) Included in earnings, net: Investment related gains (losses), net 5,532 (2,081 ) — — 32,133 — Interest credited — — — — (25,348 ) — Included in other comprehensive income — — 47 (307 ) — 1 Other revenues — — — 2,426 — 473 Purchases (1) 863 — 1,721 — (4,231 ) — Sales (1) (5,847 ) — — — — — Settlements (1) — — — — 20,044 — Transfers out of Level 3 — — (2,782 ) — — — Fair value, end of period $ 43,485 $ 142,529 $ 2,203 $ 46,090 $ (906,199 ) $ (308 ) Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment related gains (losses), net $ 2,178 $ (2,081 ) $ — $ — $ 30,433 $ — Other revenues — — — 2,426 — 473 Interest credited — — — — (45,393 ) — For the nine months ended September 30, 2018: Fixed maturity securities - available-for-sale Corporate Canadian government RMBS ABS Fair value, beginning of period $ 1,337,272 $ 593,942 $ 107,882 $ 123,474 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses (822 ) 10,432 (132 ) 202 Investment related gains (losses), net (2,902 ) — 312 1,910 Included in other comprehensive income (35,532 ) (55,632 ) (1,782 ) (821 ) Purchases (1) 379,476 — 45,328 22,099 Sales (1) (79,316 ) — (4,961 ) (462 ) Settlements (1) (245,342 ) — (4,538 ) (46,449 ) Transfers into Level 3 9,948 — 3,031 68,977 Transfers out of Level 3 (106,847 ) — (145,140 ) (86,163 ) Fair value, end of period $ 1,255,935 $ 548,742 $ — $ 82,767 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ (845 ) $ 10,432 $ — $ 187 Investment related gains (losses), net (4,571 ) — — — For the nine months ended September 30, 2018 (continued): Fixed maturity securities available-for-sale CMBS U.S. government State Other foreign government Fair value, beginning of period $ 3,234 $ 22,511 $ 41,203 $ 5,092 Total gains/losses (realized/unrealized) Included in earnings, net: Investment income, net of related expenses — (324 ) 4 — Included in other comprehensive income (56 ) (635 ) 46 (80 ) Purchases (1) — 334 — — Settlements (1) (4 ) (1,634 ) (158 ) — Transfers into Level 3 1,752 — 9,859 — Transfers out of Level 3 (3,144 ) — (37,309 ) — Fair value, end of period $ 1,782 $ 20,252 $ 13,645 $ 5,012 Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment income, net of related expenses $ — $ (325 ) $ 3 $ — For the nine months ended September 30, 2018 (continued): Equity securities Funds withheld at interest- embedded derivatives Short-term Investments Other assets - longevity swaps Interest sensitive contract liabilities embedded derivatives Other liabilities - mortality swaps Fair value, beginning of period $ — $ 122,194 $ 3,096 $ 40,659 $ (1,014,228 ) $ (1,683 ) Total gains/losses (realized/unrealized) Included in earnings, net: Investment related gains (losses), net (2,067 ) 20,335 — — 62,242 — Interest credited — — — — 6,523 — Included in other comprehensive income — — 1 (1,552 ) — 1 Other revenues — — — 6,983 — (326 ) Purchases (1) 13,111 — 2,202 — (16,946 ) — Sales (1) (6,416 ) — — — — — Settlements (1) (48 ) — (314 ) — 56,210 1,700 Transfers into Level 3 38,905 — — — — — Transfers out of Level 3 — — (2,782 ) — — — Fair value, end of period $ 43,485 $ 142,529 $ 2,203 $ 46,090 $ (906,199 ) $ (308 ) Unrealized gains and losses recorded in earnings for the period relating to those Level 3 assets and liabilities that were still held at the end of the period Included in earnings, net: Investment related gains (losses), net $ (5,527 ) $ 20,335 $ — $ — $ 56,808 $ — Other revenues — — — 6,983 — (326 ) Interest credited — — — — (49,688 ) — (1) The amount reported within purchases, sales and settlements is the purchase price (for purchases) and the sales/settlement proceeds (for sales and settlements) based upon the actual date purchased or sold/settled. Items purchased and sold/settled in the same period are excluded from the rollforward. The Company had no issuances during the period.
Fair Value, Assets and Liabilities Measured on Nonrecurring Basis [Table Text Block]	The following table (dollars in thousands) presents information for assets measured at an estimated fair value on a nonrecurring basis during the 2019 and 2018 periods presented and still held at the reporting date (for example, when there is evidence of impairment). The estimated fair values for these assets were determined using significant unobservable inputs (Level 3). Carrying Value After Measurement Investment Related Gains (Losses), Net At September 30, Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 2019 2018 Limited partnership interests (1) $ 17,785 $ 2,246 $ (3,537 ) $ (1,860 ) $ (8,586 ) $ (1,860 ) (1) The impaired limited partnership interests presented above were accounted for using the cost method. Impairments on these cost method investments were recognized at estimated fair value determined using the net asset values of the Company’s ownership interest as provided in the financial statements of the investees. The market for these investments has limited activity and price transparency.
Financial Instruments Carrying Amounts And Estimated Fair Value [Table Text Block]	The following table presents the carrying amounts and estimated fair values of the Company’s financial instruments, which were not measured at fair value on a recurring basis, as of September 30, 2019 and December 31, 2018 (dollars in thousands). For additional information regarding the methods and significant assumptions used by the Company to estimate these fair values, see Note 6 in the Notes to Consolidated Financial Statements included in the Company’s 2018 Annual Report. This table excludes any payables or receivables for collateral under repurchase agreements and other transactions. The estimated fair value of the excluded amount approximates carrying value as they equal the amount of cash collateral received/paid. September 30, 2019: Carrying Value (1) Estimated Fair Value Fair Value Measurement Using: Level 1 Level 2 Level 3 NAV Assets: Mortgage loans on real estate $ 5,647,265 $ 5,936,051 $ — $ — $ 5,936,051 $ — Policy loans 1,289,868 1,289,868 — 1,289,868 — — Funds withheld at interest 5,476,148 5,873,575 — — 5,873,575 — Cash and cash equivalents 1,708,421 1,708,421 1,708,421 — — — Short-term investments 18,373 18,373 18,373 — — — Other invested assets 1,147,167 1,205,284 5,208 82,360 737,064 380,652 Accrued investment income 520,301 520,301 — 520,301 — — Liabilities: Interest-sensitive contract liabilities $ 18,747,630 $ 20,446,240 $ — $ — $ 20,446,240 $ — Long-term debt 3,381,406 3,564,595 — — 3,564,595 — Collateral finance and securitization notes 610,246 561,011 — — 561,011 — December 31, 2018: Carrying Value (1) Estimated Fair Value Fair Value Measurement Using: Level 1 Level 2 Level 3 NAV Assets: Mortgage loans on real estate $ 4,966,298 $ 4,917,416 $ — $ — $ 4,917,416 $ — Policy loans 1,344,980 1,344,980 — 1,344,980 — — Funds withheld at interest 5,655,055 5,802,518 — — 5,802,518 — Cash and cash equivalents 1,404,566 1,404,566 1,404,566 — — — Short-term investments 36,607 36,607 36,607 — — — Other invested assets 945,731 941,449 4,640 83,203 477,214 376,392 Accrued investment income 427,893 427,893 — 427,893 — — Liabilities: Interest-sensitive contract liabilities $ 14,547,436 $ 14,611,011 $ — $ — $ 14,611,011 $ — Long-term debt 2,787,873 2,752,047 — — 2,752,047 — Collateral finance and securitization notes 681,961 626,731 — — 626,731 — (1) Carrying values presented herein may differ from those in the Company’s condensed consolidated balance sheets because certain items within the respective financial statement captions may be measured at fair value on a recurring basis.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Reconciliation Of Revenue From Segments To Consolidated Text Block	Information related to revenues, income (loss) before income taxes and total assets of the Company for each reportable segment are summarized below (dollars in thousands). Three months ended September 30, Nine months ended September 30, Revenues: 2019 2018 2019 2018 U.S. and Latin America: Traditional $ 1,609,866 $ 1,547,790 $ 4,735,208 $ 4,601,631 Financial Solutions 382,672 290,848 938,589 734,148 Total 1,992,538 1,838,638 5,673,797 5,335,779 Canada: Traditional 324,851 295,962 955,326 910,480 Financial Solutions 24,204 12,168 71,707 37,034 Total 349,055 308,130 1,027,033 947,514 Europe, Middle East and Africa: Traditional 378,110 357,059 1,131,615 1,123,379 Financial Solutions 116,800 91,664 340,207 280,482 Total 494,910 448,723 1,471,822 1,403,861 Asia Pacific: Traditional 685,886 578,035 1,992,475 1,763,094 Financial Solutions 45,702 16,167 159,788 54,005 Total 731,588 594,202 2,152,263 1,817,099 Corporate and Other 59,474 37,838 190,089 92,893 Total $ 3,627,565 $ 3,227,531 $ 10,515,004 $ 9,597,146
Reconciliation Of Operating Profit Loss From Segments To Consolidated Text Block	Three months ended September 30, Nine months ended September 30, Income (loss) before income taxes: 2019 2018 2019 2018 U.S. and Latin America: Traditional $ 112,542 $ 116,328 $ 179,371 $ 191,198 Financial Solutions 118,876 87,073 294,171 236,882 Total 231,418 203,401 473,542 428,080 Canada: Traditional 43,684 21,149 140,222 66,661 Financial Solutions 3,108 1,646 8,269 8,381 Total 46,792 22,795 148,491 75,042 Europe, Middle East and Africa: Traditional 25,342 18,370 56,887 40,259 Financial Solutions 61,246 56,205 151,437 160,738 Total 86,588 74,575 208,324 200,997 Asia Pacific: Traditional 21,453 62,007 92,852 143,756 Financial Solutions 1,886 206 9,887 8,365 Total 23,339 62,213 102,739 152,121 Corporate and Other (41,047 ) (40,323 ) (109,365 ) (148,366 ) Total $ 347,090 $ 322,661 $ 823,731 $ 707,874
Reconciliation Of Assets From Segment To Consolidated Text Block	Assets: September 30, 2019 December 31, 2018 U.S. and Latin America: Traditional $ 19,035,387 $ 19,235,781 Financial Solutions 25,522,131 19,870,388 Total 44,557,518 39,106,169 Canada: Traditional 4,248,447 4,200,792 Financial Solutions 81,684 154,000 Total 4,330,131 4,354,792 Europe, Middle East and Africa: Traditional 3,774,565 3,643,174 Financial Solutions 6,094,334 4,737,529 Total 9,868,899 8,380,703 Asia Pacific: Traditional 6,440,974 5,680,978 Financial Solutions 1,671,502 1,180,745 Total 8,112,476 6,861,723 Corporate and Other 8,904,961 5,831,858 Total $ 75,773,985 $ 64,535,245

Commitments, Contingencies an_2

Commitments, Contingencies and Guarantees (Tables)	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block]	The Company’s commitments to fund investments as of September 30, 2019 and December 31, 2018 are presented in the following table (dollars in thousands): September 30, 2019 December 31, 2018 Limited partnership interests and joint ventures $ 619,582 $ 523,903 Commercial mortgage loans 111,110 22,605 Bank loans and private placements 188,648 137,076 Lifetime mortgages 44,910 264,858
Other Commitments [Table Text Block]	The following table presents the maximum potential obligation for these commitments as of September 30, 2019 (dollars in millions): Commitment Period: Maximum Potential Obligation 2023 $ 500.0 2034 2,000.0 2035 1,314.2 2036 2,658.0 2037 5,750.0 2038 1,800.0 2039 1,750.0
Schedule of Guarantor Obligations [Table Text Block]	RGA’s guarantees issued as of September 30, 2019 and December 31, 2018 are reflected in the following table (dollars in thousands): September 30, 2019 December 31, 2018 Treaty guarantees $ 1,764,146 $ 1,392,352 Treaty guarantees, net of assets in trust 902,008 1,291,445 Securities borrowing and repurchase arrangements 273,295 269,980 Financing arrangements 41,246 61,273 Lease obligations — 392

Income Tax (Tables)

Income Tax (Tables)	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	The provision for income tax expense differed from the amounts computed by applying the U.S. federal income tax statutory rate of 21.0% to pre-tax income as a result of the following for the three and nine months ended September 30, 2019 and 2018 , respectively (dollars in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Tax provision at U.S. statutory rate $ 72,889 $ 67,759 $ 172,984 $ 148,654 Increase (decrease) in income taxes resulting from: U.S. Tax Reform provisional adjustments — 664 — (2,685 ) U.S. Tax Reform valuation allowance adjustments — (58,949 ) — (59,139 ) Foreign tax rate differing from U.S. tax rate 84 7,537 1,373 8,795 Differences in tax bases in foreign jurisdictions (9,550 ) (2,371 ) (30,626 ) (9,264 ) Deferred tax valuation allowance 27,721 (5,334 ) 50,607 5,357 Amounts related to tax audit contingencies 3,259 1,851 6,223 650 Corporate rate changes 116 (166 ) (1,621 ) 30 Subpart F (26 ) (99 ) 440 211 Foreign tax credits (651 ) (544 ) (759 ) (1,003 ) Global intangible low-taxed income, net of credit — 7,624 — 11,916 Equity compensation excess benefit (1,034 ) (817 ) (6,189 ) (5,067 ) Return to provision adjustments (8,362 ) 4,213 (4,400 ) 4,108 Other, net (121 ) 94 729 (492 ) Total provision for income taxes $ 84,325 $ 21,462 $ 188,761 $ 102,071 Effective tax rate 24.3 % 6.7 % 22.9 % 14.4 %

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Schedule Of Defined Benefit Plans Disclosures Text Block	The components of net periodic benefit costs, included in other operating expenses on the condensed consolidated statements of income, for the three and nine months ended September 30, 2019 and 2018 were as follows (dollars in thousands): Pension Benefits Other Benefits Three months ended September 30, Three months ended September 30, 2019 2018 2019 2018 Service cost $ 3,158 $ 3,106 $ 461 $ 999 Interest cost 1,662 1,341 827 680 Expected return on plan assets (1,788 ) (1,884 ) — — Amortization of prior service cost (credit) 61 82 (328 ) (328 ) Amortization of prior actuarial losses 1,073 929 29 937 Net periodic benefit cost $ 4,166 $ 3,574 $ 989 $ 2,288 Pension Benefits Other Benefits Nine months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Service cost $ 9,465 $ 9,330 $ 1,975 $ 2,271 Interest cost 4,979 4,028 1,986 1,739 Expected return on plan assets (5,364 ) (5,651 ) — — Amortization of prior service cost (credit) 182 247 (986 ) (986 ) Amortization of prior actuarial losses 3,215 2,792 1,317 1,933 Net periodic benefit cost $ 12,477 $ 10,746 $ 4,292 $ 4,957

Reinsurance (Tables)

Reinsurance (Tables)	9 Months Ended
	Sep. 30, 2019
Retrocession Arrangements And Reinsurance Ceded Receivables [Abstract]
Ceded Credit Risk [Table Text Block]	The following table presents information for the Company’s reinsurance ceded receivable assets, including the respective amount and A.M. Best rating for each reinsurer representing in excess of five percent of the total as of September 30, 2019 or December 31, 2018 (dollars in thousands): September 30, 2019 December 31, 2018 Reinsurer A.M. Best Rating Amount % of Total Amount % of Total Reinsurer A A+ $ 358,845 41.6 % $ 303,036 40.0 % Reinsurer B A+ 201,011 23.3 193,324 25.5 Reinsurer C A 76,807 8.9 69,885 9.2 Reinsurer D A++ 57,247 6.6 36,600 4.8 Reinsurer E A+ 40,816 4.7 40,004 5.3 Other reinsurers 128,301 14.9 114,723 15.2 Total $ 863,027 100.0 % $ 757,572 100.0 %

Policy Claims and Benefits (Tab

Policy Claims and Benefits (Tables)	9 Months Ended
	Sep. 30, 2019
Insurance [Abstract]
Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]	The liability for unpaid claims is reported in future policy benefits and other policy-related balances within the Company’s consolidated balance sheet. Activity associated with unpaid claims is summarized below (dollars in thousands): Nine months ended September 30, 2019 2018 Balance at beginning of year $ 6,584,668 $ 5,896,469 Less: reinsurance recoverable (432,582 ) (455,547 ) Net balance at beginning of year 6,152,086 5,440,922 Incurred: Current year 8,203,842 7,534,297 Prior years 108,023 97,336 Total incurred 8,311,865 7,631,633 Payments: Current year (2,937,099 ) (2,748,547 ) Prior years (4,774,623 ) (4,222,550 ) Total payments (7,711,722 ) (6,971,097 ) Other changes: Interest accretion 19,887 18,550 Foreign exchange adjustments (99,788 ) (153,247 ) Total other changes (79,901 ) (134,697 ) Net balance at end the period 6,672,328 5,966,761 Plus: reinsurance recoverable 508,003 424,545 Balance at end of the period $ 7,180,331 $ 6,391,306

Earnings Per Share (Reconciliat

Earnings Per Share (Reconciliation of the Numerators and Denominators of the Basic and Diluted Per Shares) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net Income (Loss) Available to Common Stockholders, Basic [Abstract]
Net income (numerator for basic and diluted calculations)	$ 262,765	$ 301,199	$ 634,970	$ 605,803
Shares:
Weighted average outstanding shares (denominator for basic calculation)	62,666	63,279	62,701	63,941
Equivalent shares from outstanding stock options	1,123	1,017	1,218	1,189
Denominator for diluted calculation	63,789	64,296	63,919	65,130
Earnings Per Share:
Basic earnings per share	$ 4.19	$ 4.76	$ 10.13	$ 9.47
Diluted earnings per share	$ 4.12	$ 4.68	$ 9.93	$ 9.30

Earnings Per Share (Stock Optio

Earnings Per Share (Stock Options and Performance Shares Excluded From Common Equivalent Shares) (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement, Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	139	227	416	349
Share-based Payment Arrangement [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	258	276	182	256

Equity (Common Stock Changes In

Equity (Common Stock Changes In Number of Shares Issued, Held In Treasury and Outstanding) (Details) - shares		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Common Stock, Shares, Issued		79,137,758			79,137,758
Treasury Stock, Shares, Acquired				(1,800,000)
Common Stock Issuable [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued		79,137,758	79,137,758	79,137,758	79,137,758	79,137,758
Treasury Stock, Shares, Acquired		0	0
Stock Based Compensation Shares	[1]	0	0
Common Stock Held In Treasury [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued		16,528,557	16,186,890	16,186,890	16,323,390	14,685,663
Treasury Stock, Shares, Acquired		(546,614)	(1,750,295)
Stock Based Compensation Shares	[1]	(341,447)	(249,068)
Common Stock Outstanding [Member]
Class of Stock [Line Items]
Common Stock, Shares, Issued		62,609,201	62,950,868	62,950,868	62,814,368	64,452,095
Treasury Stock, Shares, Acquired		(546,614)	(1,750,295)
Stock Based Compensation Shares	[1]	(341,447)	(249,068)
[1]	Represents net shares issued from treasury pursuant to the Company’s equity-based compensation programs.

Equity (Balance of and Changes

Equity (Balance of and Changes in Each Component of AOCI) (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Accumulated other comprehensive income		$ 812,805	$ 3,258,346	$ 812,805	$ 636,763	$ 2,063,631
Other Comprehensive Income (Loss), before Reclassifications, before Tax			3,530,571	(1,666,514)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			(166,803)	83,491
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		0	(87)	(2,020)
Other Comprehensive Income (Loss), Tax			(742,185)	334,770
Accumulated Translation Adjustment [Member]
Accumulated other comprehensive income		(119,298)	(157,174)	(119,298)	(168,698)	(86,350)
Other Comprehensive Income (Loss), before Reclassifications, before Tax			16,155	(24,977)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			0	0
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				(2,573)
Other Comprehensive Income (Loss), Tax			4,631	5,398
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated other comprehensive income	[1]	982,352	3,472,549	982,352	856,159	2,200,661
Other Comprehensive Income (Loss), before Reclassifications, before Tax	[1]		3,526,151	(1,638,146)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	[1]		(170,531)	79,505
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	[1]			0
Other Comprehensive Income (Loss), Tax	[1]		(739,230)	340,332
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated other comprehensive income		$ (50,249)	(57,029)	(50,249)	$ (50,698)	$ (50,680)
Other Comprehensive Income (Loss), before Reclassifications, before Tax			(11,735)	(3,391)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			3,728	3,986
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				0
Other Comprehensive Income (Loss), Tax			$ 1,676	$ (164)
[1]	Includes cash flow hedges of $(47,202) and $8,788 as of September 30, 2019 and December 31, 2018 , respectively, and $29,043 and $2,619 as of September 30, 2018 and December 31, 2017 , respectively. See Note 5 - “Derivative Instruments” for additional information on cash flow hedges.

Equity (Balance of and Change_2

Equity (Balance of and Changes in Each Component of AOCI) (Footnote) (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended		12 Months Ended
		Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				$ 0		$ (87)	$ (2,020)
Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		$ (47,202)	$ (14,862)	$ 29,043	$ 22,656	$ (47,202)	29,043	$ 8,788	$ 2,619
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Derivative Instruments, Gain (Loss) [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification							(2,573)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Derivative Instruments, Gain (Loss) [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	[1]						0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Derivative Instruments, Gain (Loss) [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification							$ 0
[1]	Includes cash flow hedges of $(47,202) and $8,788 as of September 30, 2019 and December 31, 2018 , respectively, and $29,043 and $2,619 as of September 30, 2018 and December 31, 2017 , respectively. See Note 5 - “Derivative Instruments” for additional information on cash flow hedges.

Equity (Schedule of Reclassific

Equity (Schedule of Reclassifications out of AOCI) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Investment related gains (losses), net		$ 57,323	$ (9,312)	$ 87,036	$ (17,004)
Investment income		678,805	572,742	1,842,760	1,617,132
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest		347,090	322,661	823,731	707,874
Income Tax Expense (Benefit)		(84,325)	(21,462)	(188,761)	(102,071)
Net income		262,765	301,199	634,970	605,803
Unrealized Appreciation Depreciation Of Investments [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest		72,029	(25,858)	170,531	(79,505)
Income Tax Expense (Benefit)		(14,808)	5,355	(35,087)	16,978
Net income		57,221	(20,503)	135,444	(62,527)
Unrealized Appreciation Depreciation Of Investments [Member] | Unrealized Gains Losses On Available For Sale Securities [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Investment related gains (losses), net		50,537	(21,249)	70,513	(60,347)
Unrealized Appreciation Depreciation Of Investments [Member] | Interest Rate Swap [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[1]	255	234	1,107	(108)
Unrealized Appreciation Depreciation Of Investments [Member] | Currency Swap [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[1]	(38)	50	(19)	270
Unrealized Appreciation Depreciation Of Investments [Member] | DAC Attributed To Unrealized Gains Losses [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Deferred policy acquisition costs attributed to unrealized gains and losses	[2]	21,275	(4,893)	(98,930)	(19,320)
Amortization Of Unrealized Pension And Postretirement Benefits [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest		(835)	(1,620)	(3,728)	(3,986)
Income Tax Expense (Benefit)		175	340	783	837
Net income		(660)	(1,280)	(2,945)	(3,149)
Amounts Reclassified From AOCI [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net income		56,561	(21,783)	132,499	(65,676)
Prior Service Cost [Member] | Amortization Of Unrealized Pension And Postretirement Benefits [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Prior service cost	[3]	267	246	804	739
Actuarial Gains Losses [Member] | Amortization Of Unrealized Pension And Postretirement Benefits [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Actuarial gains/(losses)	[3]	$ (1,102)	$ (1,866)	$ 4,532	$ (4,725)
[1]	See Note 5 - “Derivative Instruments” for additional information on cash flow hedges.
[2]	This AOCI component is included in the computation of the deferred policy acquisition cost. See Note 8 – “Deferred Policy Acquisition Costs” of the 2018 Annual Report for additional details.
[3]	This AOCI component is included in the computation of the net periodic pension cost. See Note 10 – “Employee Benefit Plans” for additional details.

Equity (Narrative) (Details)

Equity (Narrative) (Details) - USD ($) $ in Thousands, shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Equity, Class of Treasury Stock [Line Items]
Treasury Stock, Shares, Acquired				1.8
Treasury Stock, Value, Acquired, Cost Method	$ (30,487)	$ (108,804)	$ (98,231)	$ (273,873)
Stock Repurchase Program, Authorized Amount	$ 400,000		$ 400,000
RGA Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Treasury Stock, Shares, Acquired			0.5
Treasury Stock, Value, Acquired, Cost Method			$ 79,800	$ 258,500

Equity Based Compensation (Narr

Equity Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement [Abstract]
Equity compensation expense	$ 29.3	$ 28.4
Stock appreciation rights granted	200,000
Stock appreciation rights granted, weighted average exercise price (per share)	$ 145.25
Performance contingent units	100,000
Shares Granted To Non Employee Directors	8,472
Options exercisable (shares)	1,400,000
Options exercisable, weighted average price (per share)	$ 76.08
Options, remaining term	4 years 1 month 6 days
Compensation cost not yet recognized	$ 26.5
Period for recognition	10 months 24 days

Investments (Investments in Fix

Investments (Investments in Fixed Maturity Securities Available-for-Sale by Sector) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 44,860,441	$ 38,882,168
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	4,723,069	1,858,668
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	102,243	748,490
Estimated Fair Value	$ 49,481,267	$ 39,992,346
% of Total	100.00%	100.00%
Other-than-temporary impairments in AOCI	$ 275	$ 275
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	28,154,301	24,006,407
Estimated Fair Value	$ 30,353,219	$ 23,982,119
% of Total	100.00%	100.00%
Corporate Debt Securities [Member] | Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 28,154,301	$ 24,006,407
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	2,277,070	530,804
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	78,152	555,092
Estimated Fair Value	$ 30,353,219	$ 23,982,119
% of Total	61.30%	59.90%
Other-than-temporary impairments in AOCI	$ 0	$ 0
Canadian and Canadian provincial governments | Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,962,729	2,768,466
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	1,670,680	1,126,227
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	190	2,308
Estimated Fair Value	$ 4,633,219	$ 3,892,385
% of Total	9.40%	9.70%
Other-than-temporary impairments in AOCI	$ 0	$ 0
Residential mortgage-backed securities | Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,360,691	1,872,236
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	81,367	22,267
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	2,216	25,282
Estimated Fair Value	$ 2,439,842	$ 1,869,221
% of Total	4.90%	4.70%
Other-than-temporary impairments in AOCI	$ 0	$ 0
Asset-backed securities | Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,809,008	2,171,254
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	27,621	10,779
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	13,994	32,829
Estimated Fair Value	$ 2,822,635	$ 2,149,204
% of Total	5.70%	5.40%
Other-than-temporary impairments in AOCI	$ 275	$ 275
Commercial Mortgage Backed Securities [Member] | Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,698,334	1,428,115
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	84,345	9,153
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	461	18,234
Estimated Fair Value	$ 1,782,218	$ 1,419,034
% of Total	3.60%	3.50%
Other-than-temporary impairments in AOCI	$ 0	$ 0
US Treasury and Government [Member] | Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,570,540	2,233,537
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	98,193	10,204
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	228	57,867
Estimated Fair Value	$ 1,668,505	$ 2,185,874
% of Total	3.40%	5.50%
Other-than-temporary impairments in AOCI	$ 0	$ 0
US States and Political Subdivisions Debt Securities [Member] | Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,078,019	721,290
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	113,684	39,914
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	1,600	9,010
Estimated Fair Value	$ 1,190,103	$ 752,194
% of Total	2.40%	1.90%
Other-than-temporary impairments in AOCI	$ 0	$ 0
Debt Security, Government, Non-US [Member] | Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,226,819	3,680,863
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	370,109	109,320
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	5,402	47,868
Estimated Fair Value	$ 4,591,526	$ 3,742,315
% of Total	9.30%	9.40%
Other-than-temporary impairments in AOCI	$ 0	$ 0

Investments (Fixed Maturity Sec

Investments (Fixed Maturity Securities Pledged And Received As Collateral) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Document Period End Date	Sep. 30, 2019
Collateral Fixed Maturity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 95,387	$ 80,891
Available-for-sale Securities	99,393	83,950
Collateral Received Fixed Maturity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	696,435	616,584
Reported Value Measurement [Member]
Debt Securities, Available-for-sale [Line Items]
Assets Held-in-trust	26,332,915	20,072,735
Estimate of Fair Value Measurement [Member]
Debt Securities, Available-for-sale [Line Items]
Assets Held-in-trust	$ 28,368,125	$ 20,366,170

Investments (Exposure To Concen

Investments (Exposure To Concentrations Of Credit Risk) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Document Period End Date	Sep. 30, 2019
Canadian Province Of Quebec Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	$ 981,279	$ 913,642
Available-for-sale Securities	1,371,571	1,187,526
Canadian Province Of Ontario Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Amortized Cost Basis	1,167,744	1,091,018
Available-for-sale Securities	$ 2,153,434	$ 1,757,087

Investments (Amortized Cost and

Investments (Amortized Cost and Fair Value of Fixed Maturities by Contractual Maturities) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Available For Sale Securities Debt Maturities Amortized Cost
Due in one year or less	$ 1,538,152
Due after one year through five years	8,318,044
Due after five year through ten years	9,485,912
Due after ten years	18,650,300
Asset and mortgage-backed securities	6,868,033
Total	44,860,441	$ 38,882,168
Available For Sale Securities Debt Maturities Fair Value
Due in one year or less	1,547,966
Due after one year through five years	8,656,979
Due after five year through ten years	10,275,538
Due after ten years	21,956,089
Asset and mortgage-backed securities	7,044,695
Total	$ 49,481,267	$ 39,992,346

Investments (Amortized Cost a_2

Investments (Amortized Cost and Fair Value of Fixed Maturity Holdings by Industry Type) (Details) - Corporate Debt Securities [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 28,154,301	$ 24,006,407
Estimated Fair Value	$ 30,353,219	$ 23,982,119
% of Total	100.00%	100.00%
Financial Services Sector [Member]
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 10,604,290	$ 8,793,742
Estimated Fair Value	$ 11,327,324	$ 8,730,568
% of Total	37.30%	36.30%
Commercial and Industrial Sector [Member]
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 14,099,496	$ 12,336,857
Estimated Fair Value	$ 15,213,256	$ 12,342,111
% of Total	50.10%	51.60%
Utility Sector [Member]
Corporate Securities by Investment Sector And Credit Rating [Line Items]
Amortized Cost	$ 3,450,515	$ 2,875,808
Estimated Fair Value	$ 3,812,639	$ 2,909,440
% of Total	12.60%	12.10%

Investments (Fair Value Below A

Investments (Fair Value Below Amortized Cost of Gross Unrealized Losses for Fixed Maturity Securities) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Gross unrealized losses with number of securities [Line Items]
Document Period End Date	Sep. 30, 2019
Gross Unrealized Losses	$ 102,243	$ 748,490
% of Total	100.00%	100.00%
Less than 20%
Gross unrealized losses with number of securities [Line Items]
Gross Unrealized Losses	$ 75,658	$ 721,015
% of Total	74.00%	96.30%
20% or more for less than six months
Gross unrealized losses with number of securities [Line Items]
Gross Unrealized Losses	$ 10,064	$ 21,336
% of Total	9.80%	2.90%
20% or more for six months or greater
Gross unrealized losses with number of securities [Line Items]
Gross Unrealized Losses	$ 16,521	$ 6,139
% of Total	16.20%	0.80%

Investments (Fair Value and Los

Investments (Fair Value and Losses by Investment Category and Length of Time in a Loss Position) (Details) - Fixed maturity securities - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	$ 3,039,667	$ 12,073,860
Gross Unrealized Losses - Less than 12 months	60,114	408,581
Estimated Fair Value - 12 months or greater	1,251,213	7,226,996
Gross Unrealized Losses - 12 months or greater	42,129	339,909
Estimated Fair Value	4,290,880	19,300,856
Gross Unrealized Losses	102,243	748,490
Non-investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	220,064	884,847
Gross Unrealized Losses - Less than 12 months	24,862	48,368
Estimated Fair Value - 12 months or greater	136,782	133,897
Gross Unrealized Losses - 12 months or greater	17,305	15,297
Estimated Fair Value	356,846	1,018,744
Gross Unrealized Losses	42,167	63,665
Investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	2,819,603	11,189,013
Gross Unrealized Losses - Less than 12 months	35,252	360,213
Estimated Fair Value - 12 months or greater	1,114,431	7,093,099
Gross Unrealized Losses - 12 months or greater	24,824	324,612
Estimated Fair Value	3,934,034	18,282,112
Gross Unrealized Losses	60,076	684,825
Corporate Debt Securities [Member] | Non-investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	206,108	755,679
Gross Unrealized Losses - Less than 12 months	24,561	42,760
Estimated Fair Value - 12 months or greater	122,670	122,559
Gross Unrealized Losses - 12 months or greater	16,417	14,646
Estimated Fair Value	328,778	878,238
Gross Unrealized Losses	40,978	57,406
Corporate Debt Securities [Member] | Investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	1,570,113	8,505,371
Gross Unrealized Losses - Less than 12 months	25,598	302,604
Estimated Fair Value - 12 months or greater	410,462	3,611,266
Gross Unrealized Losses - 12 months or greater	11,576	195,082
Estimated Fair Value	1,980,575	12,116,637
Gross Unrealized Losses	37,174	497,686
Canadian and Canadian provincial governments | Non-investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months		443
Gross Unrealized Losses - Less than 12 months		34
Estimated Fair Value - 12 months or greater		1,770
Gross Unrealized Losses - 12 months or greater		243
Estimated Fair Value		2,213
Gross Unrealized Losses		277
Canadian and Canadian provincial governments | Investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	867	25,169
Gross Unrealized Losses - Less than 12 months	10	419
Estimated Fair Value - 12 months or greater	17,509	131,806
Gross Unrealized Losses - 12 months or greater	180	1,612
Estimated Fair Value	18,376	156,975
Gross Unrealized Losses	190	2,031
Residential mortgage-backed securities | Non-investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	0	0
Gross Unrealized Losses - Less than 12 months	0	0
Estimated Fair Value - 12 months or greater	939	1,026
Gross Unrealized Losses - 12 months or greater	11	34
Estimated Fair Value	939	1,026
Gross Unrealized Losses	11	34
Residential mortgage-backed securities | Investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	222,644	269,558
Gross Unrealized Losses - Less than 12 months	987	2,488
Estimated Fair Value - 12 months or greater	116,037	836,741
Gross Unrealized Losses - 12 months or greater	1,218	22,760
Estimated Fair Value	338,681	1,106,299
Gross Unrealized Losses	2,205	25,248
Asset-backed securities | Non-investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months		0
Gross Unrealized Losses - Less than 12 months		0
Estimated Fair Value - 12 months or greater		1,063
Gross Unrealized Losses - 12 months or greater		35
Estimated Fair Value		1,063
Gross Unrealized Losses		35
Asset-backed securities | Investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	765,223	1,102,677
Gross Unrealized Losses - Less than 12 months	4,861	24,271
Estimated Fair Value - 12 months or greater	413,297	381,609
Gross Unrealized Losses - 12 months or greater	9,133	8,523
Estimated Fair Value	1,178,520	1,484,286
Gross Unrealized Losses	13,994	32,794
Commercial mortgage-backed securities | Non-investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	1,042
Gross Unrealized Losses - Less than 12 months	11
Estimated Fair Value - 12 months or greater	0
Gross Unrealized Losses - 12 months or greater	0
Commercial mortgage-backed securities | Investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	48,699	384,259
Gross Unrealized Losses - Less than 12 months	218	4,304
Estimated Fair Value - 12 months or greater	32,638	414,719
Gross Unrealized Losses - 12 months or greater	232	13,930
Estimated Fair Value	81,337	798,978
Gross Unrealized Losses	450	18,234
US Government Agencies Debt Securities [Member] | Investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	2,758	8,616
Gross Unrealized Losses - Less than 12 months	7	80
Estimated Fair Value - 12 months or greater	65,220	1,086,694
Gross Unrealized Losses - 12 months or greater	221	57,787
Estimated Fair Value	67,978	1,095,310
Gross Unrealized Losses	228	57,867
US States and Political Subdivisions Debt Securities [Member] | Investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	11,129	103,504
Gross Unrealized Losses - Less than 12 months	97	1,538
Estimated Fair Value - 12 months or greater	13,838	157,330
Gross Unrealized Losses - 12 months or greater	1,503	7,472
Estimated Fair Value	24,967	260,834
Gross Unrealized Losses	1,600	9,010
Debt Security, Government, Non-US [Member] | Non-investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	12,914	128,725
Gross Unrealized Losses - Less than 12 months	290	5,574
Estimated Fair Value - 12 months or greater	13,173	7,479
Gross Unrealized Losses - 12 months or greater	877	339
Estimated Fair Value	26,087	136,204
Gross Unrealized Losses	1,167	5,913
Debt Security, Government, Non-US [Member] | Investment grade securities
Estimated Fair Values And Gross Unrealized Losses, OTTI Impairment Losses Reported In AOCI [Line Items]
Estimated Fair Value - Less than 12 months	198,170	789,859
Gross Unrealized Losses - Less than 12 months	3,474	24,509
Estimated Fair Value - 12 months or greater	45,430	472,934
Gross Unrealized Losses - 12 months or greater	761	17,446
Estimated Fair Value	243,600	1,262,793
Gross Unrealized Losses	$ 4,235	$ 41,955

Investments (Investment Income

Investments (Investment Income Net of Related Expenses) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	$ 702,416	$ 596,035	$ 1,912,026	$ 1,684,151
Investment expense	(23,611)	(23,293)	(69,266)	(67,019)
Investment income, net of related expenses	678,805	572,742	1,842,760	1,617,132
Available-for-sale Securities [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	464,431	378,669	1,307,359	1,121,496
Equity securities
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	1,709	1,319	3,600	3,710
Mortgage Loans on Real Estate [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	67,071	54,424	187,142	155,083
Policy loans
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	14,580	14,730	43,083	44,285
Funds withheld at interest
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	81,862	108,232	209,568	270,094
Short-term Investments [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	6,152	3,067	20,517	9,276
Other invested assets
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	$ 66,611	$ 35,594	$ 140,757	$ 80,207

Investments (Investment Related

Investments (Investment Related Gains (Losses) Net) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Investments [Abstract]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	$ (8,539)	$ (10,705)	$ (17,992)	$ (14,055)
Investment Gains And Losses [Abstract]
Gain on investment activity	(67,980)	(20,040)	(116,409)	(52,146)
Available-for-sale Securities, Realized Losses, Excluding Other than Temporary Impairments	(12,996)	(37,880)	(38,589)	(94,194)
Available-for-sale Equity Securities, Gross Unrealized Gain	432	3,932	506	4,429
Available-for-sale Equity Securities, Gross Unrealized Loss	0	(174)	(1)	(1,124)
Gain (Loss) on Sale of Equity Investments	3,396	3,539	9,813	(7,564)
Other impairment losses and change in mortgage loan provision	(4,030)	(6,566)	(11,498)	(8,235)
Derivatives and other, net	2,541	7,797	10,396	37,538
Total investment related gains (losses), net	$ 48,784	$ (20,017)	$ 69,044	$ (31,059)

Investments (Borrowed Securitie

Investments (Borrowed Securities Repurchased Securities And Repurchased Reversed Repurchased Securities) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Document Period End Date	Sep. 30, 2019
Securities Loaned, Fair Value of Collateral	$ 104,191	$ 102,618
Securities Received as Collateral	107,000	112,000
Securities for Reverse Repurchase Agreements	610,701	554,806
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities	624,348	530,932
Reported Value Measurement [Member]
Debt Securities, Available-for-sale [Line Items]
Securities Borrowed	335,408	335,781
Securities Loaned, Fair Value of Collateral	97,606	101,981
Estimate of Fair Value Measurement [Member]
Debt Securities, Available-for-sale [Line Items]
Securities Borrowed	372,617	366,663
Securities for Reverse Repurchase Agreements	$ 644,471	$ 554,589

Investments (Securities Pledged

Investments (Securities Pledged as Collateral Related to Repurchase Reverse Repurchase Program) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Assets Sold under Agreements to Repurchase [Line Items]
Document Period End Date	Sep. 30, 2019
Securities Loaned, Fair Value of Collateral	$ 104,191	$ 102,618
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	644,471	554,589
Obligation to Return Securities Received as Collateral	748,662	657,207
Securities Sold under Agreements to Repurchase, Gross Including Not Subject to Master Netting Arrangement	758,883	671,492
SecuredBorrowingsGrossDifferenceAmount	10,221	14,285
Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0	0
Obligation to Return Securities Received as Collateral	0	0
Maturity up to 30 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0	0
Obligation to Return Securities Received as Collateral	0	0
Maturity 30 to 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	66,264	0
Obligation to Return Securities Received as Collateral	66,264	0
Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	578,207	554,589
Obligation to Return Securities Received as Collateral	682,398	657,207
Corporate Debt Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Fair Value of Collateral	104,191	102,618
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	324,033	254,151
Corporate Debt Securities [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Fair Value of Collateral	0	0
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0	0
Corporate Debt Securities [Member] | Maturity up to 30 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Fair Value of Collateral	0	0
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0	0
Corporate Debt Securities [Member] | Maturity 30 to 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Fair Value of Collateral	0	0
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0	0
Corporate Debt Securities [Member] | Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Loaned, Fair Value of Collateral	104,191	102,618
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	324,033	254,151
US Government Agencies Debt Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement		221,572
US Government Agencies Debt Securities [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement		0
US Government Agencies Debt Securities [Member] | Maturity up to 30 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement		0
US Government Agencies Debt Securities [Member] | Maturity 30 to 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement		0
US Government Agencies Debt Securities [Member] | Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement		221,572
US Treasury and Government [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	208,388
US Treasury and Government [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0
US Treasury and Government [Member] | Maturity up to 30 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0
US Treasury and Government [Member] | Maturity 30 to 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	66,264
US Treasury and Government [Member] | Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	142,124
Debt Security, Government, Non-US [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	112,050	78,866
Debt Security, Government, Non-US [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0	0
Debt Security, Government, Non-US [Member] | Maturity up to 30 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0	0
Debt Security, Government, Non-US [Member] | Maturity 30 to 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0	0
Debt Security, Government, Non-US [Member] | Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	112,050	$ 78,866
Other Debt Obligations [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0
Other Debt Obligations [Member] | Maturity Overnight [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0
Other Debt Obligations [Member] | Maturity up to 30 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0
Other Debt Obligations [Member] | Maturity 30 to 90 Days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	0
Other Debt Obligations [Member] | Maturity over 90 days [Member]
Assets Sold under Agreements to Repurchase [Line Items]
FinancialAssetsSoldUnderAgreementsToRepurchaseGrossIncludingNotSubjectToMasterNettingArrangement	$ 0

Investments (Mortgage Loans by

Investments (Mortgage Loans by Property Type) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Recorded investment	$ 5,667,354		$ 4,983,354
Percentage of total	100.00%		100.00%
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	$ (8,314)		$ (5,770)
Allowance for Loan and Lease Losses, Real Estate	(11,775)	$ (11,692)	(11,286)	$ (10,366)	$ (9,706)	$ (9,384)
Mortgage loans on real estate (net of allowances of $11,775 and $11,286)	5,647,265		4,966,298
Apartment
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Recorded investment	$ 748,392		$ 571,291
Percentage of total	13.20%		11.50%
Retail
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Recorded investment	$ 1,645,521		$ 1,432,394
Percentage of total	29.00%		28.70%
Office building
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Recorded investment	$ 1,787,871		$ 1,725,748
Percentage of total	31.60%		34.60%
Industrial
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Recorded investment	$ 1,137,598		$ 961,924
Percentage of total	20.10%		19.30%
Other commercial
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Recorded investment	$ 347,972		$ 291,997
Percentage of total	6.10%		5.90%

Investments (Mortgage Loans b_2

Investments (Mortgage Loans by Maturity Date) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Document Period End Date	Sep. 30, 2019
Financing Receivable, before Allowance for Credit Loss	$ 5,667,354	$ 4,983,354
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	100.00%	100.00%
Due within five years
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 1,750,771	$ 1,425,598
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	30.90%	28.60%
Due after five years through ten years
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 3,001,527	$ 2,686,264
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	53.00%	53.90%
Due after ten years
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 915,056	$ 871,492
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	16.10%	17.50%

Investments (Mortgage Loans b_3

Investments (Mortgage Loans by Credit Quality Indicator) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 5,667,354	$ 4,983,354
Loans Receivable, Gross, Commercial, Construction	$ 21,434	$ 32,620
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	100.00%	100.00%
LTV 0 to 59 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 3,038,993	$ 2,523,670
Loans Receivable, Gross, Commercial, Construction	$ 21,434	$ 13,691
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	53.60%	50.60%
LTV 60 To 69 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 2,011,116	$ 1,749,331
Loans Receivable, Gross, Commercial, Construction	$ 0	$ 18,929
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	35.50%	35.10%
LTV 70 To 79 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 428,185	$ 517,147
Loans Receivable, Gross, Commercial, Construction	$ 0	$ 0
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	7.60%	10.40%
Debt-to-Value Ratio, 80 to 100 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 189,060	$ 193,206
Loans Receivable, Gross, Commercial, Construction	$ 0	$ 0
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	3.30%	3.90%
Debt Service Coverage Ratio Range One [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 5,314,858	$ 4,561,177
Debt Service Coverage Ratio Range One [Member] | LTV 0 to 59 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	2,912,673	2,410,556
Debt Service Coverage Ratio Range One [Member] | LTV 60 To 69 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	1,889,981	1,618,374
Debt Service Coverage Ratio Range One [Member] | LTV 70 To 79 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	395,599	414,269
Debt Service Coverage Ratio Range One [Member] | Debt-to-Value Ratio, 80 to 100 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	116,605	117,978
Debt Service Coverage Ratio Range Two [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	224,855	233,260
Debt Service Coverage Ratio Range Two [Member] | LTV 0 to 59 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	91,954	61,246
Debt Service Coverage Ratio Range Two [Member] | LTV 60 To 69 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	83,814	73,908
Debt Service Coverage Ratio Range Two [Member] | LTV 70 To 79 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	0	48,438
Debt Service Coverage Ratio Range Two [Member] | Debt-to-Value Ratio, 80 to 100 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	49,087	49,668
Debt Service Coverage Ratio Range Three [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	106,207	156,297
Debt Service Coverage Ratio Range Three [Member] | LTV 0 to 59 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	12,932	38,177
Debt Service Coverage Ratio Range Three [Member] | LTV 60 To 69 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	37,321	38,120
Debt Service Coverage Ratio Range Three [Member] | LTV 70 To 79 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	32,586	54,440
Debt Service Coverage Ratio Range Three [Member] | Debt-to-Value Ratio, 80 to 100 Percent [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans Receivable, Gross, Commercial, Real Estate	$ 23,368	$ 25,560

Investments (Age Analysis of Pa

Investments (Age Analysis of Past Due Recorded Investments) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Document Period End Date	Sep. 30, 2019
Financing Receivable, Past Due	$ 21,065	$ 0
Financing Receivable, Not Past Due	5,646,289	4,983,354
Loans Receivable, Gross, Commercial, Real Estate	5,667,354	4,983,354
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	$ 21,065	$ 0

Investments (Mortgage Loans b_4

Investments (Mortgage Loans by Method of Evaluation and Related Valuation Allowances) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Loss [Line Items]
Document Period End Date	Sep. 30, 2019
Mortgage Loans:
Total mortgage loans	$ 5,667,354	$ 4,983,354
Mortgage Loans on Real Estate, Commercial and Consumer, Net, (Investment Based Operations Presentation) [Abstract]
Mortgage loans on real estate (net of valuation allowances)	5,647,265	4,966,298
Commercial Real Estate Portfolio Segment [Member]
Mortgage Loans:
Evaluated individually for credit losses	17,016	30,635
Evaluated collectively for credit losses	5,650,338	4,952,719
Total mortgage loans	5,667,354	4,983,354
Valuation Allowances:
Specific for credit losses	0	0
Non-specifically identified credit losses	11,775	11,286
Total valuation allowances	$ 11,775	$ 11,286

Investments (Loan Valuation All

Investments (Loan Valuation Allowance for Mortgage Loans) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Allowance For Loan And Lease Losses Roll Forward
Balance, Beginning of Period	$ 11,692	$ 9,706	$ 11,286	$ 9,384
Provision (release)	88	656	485	986
Allowance for Loan and Lease Losses, Foreign Currency Translation	(5)	4	4	(4)
Balance, End of Period	$ 11,775	$ 10,366	$ 11,775	$ 10,366

Investments (Impaired Mortgage

Investments (Impaired Mortgage Loans) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019		Sep. 30, 2018	Dec. 31, 2018
Financing Receivable Impaired [Line Items]
Unpaid Principal Balance		$ 17,017		$ 17,017			$ 30,660
Recorded Investment		17,016		17,016			30,635
Related Allowance		0		0			0
Carrying Value		17,016		17,016			30,635
Average Investment	[1]	17,015	$ 30,641	20,436		$ 22,641
Interest Income		170	346	669		650
Impaired mortgage loans with valuation allowance recorded
Financing Receivable Impaired [Line Items]
Unpaid Principal Balance		0		0			0
Recorded Investment		0		0			0
Related Allowance		0		0			0
Carrying Value		0		0			0
Average Investment	[1]	0	0			0
Interest Income		0	0	0	[1]	0
Impaired mortgage loans with no valuation allowance recorded
Financing Receivable Impaired [Line Items]
Unpaid Principal Balance		17,017		17,017			30,660
Recorded Investment		17,016		17,016			30,635
Related Allowance		0		0			0
Carrying Value		17,016		17,016			$ 30,635
Average Investment	[1]	17,015	30,641	20,436		22,641
Interest Income		$ 170	$ 346	$ 669		$ 650
[1]	Average recorded investment represents the average loan balances as of the beginning of period and all subsequent quarterly end of period balances.

Investments (Other Invested Ass

Investments (Other Invested Assets) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Document Period End Date	Sep. 30, 2019
Other invested assets	$ 2,215,275	$ 1,915,297
Equity Release Mortgages [Member]
Other invested assets	669,981	475,905
Limited Partner [Member]
Other invested assets	1,059,025	965,094
Derivatives
Other invested assets	142,099	180,699
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Other invested assets	252,277	197,770
Other
Other invested assets	$ 91,893	$ 95,829

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Investment Narrative [Line Items]
Document Period End Date			Sep. 30, 2019
Funds Held Under Reinsurance Agreements Asset Specific Client	$ 3,600,000		$ 3,600,000
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held	3,700		3,700
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash	27,500		27,500		$ 28,600
Net Amount Assets Liabilities From Repurchase Reverse Repurchase Agreements	500		500		$ 400
Proceeds From Sale Of Available For Sale Securities Sold At Loss	1,313,700	$ 1,345,300	3,026,500	$ 3,783,300
Available-for-sale Securities, Realized Losses, Excluding Other than Temporary Impairments	$ 12,996	37,880	$ 38,589	94,194
Policy Loans Percent Of Total Investments	2.00%		2.00%		2.50%
Mortgage Loan Percent Of Cash And Invested Assets	8.80%		8.80%		9.10%
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	856		856		3,109
Securities As Percentage Of Consolidated Stockholder Equity	10.00%		10.00%
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	100.00%		100.00%		100.00%
Funds Withheld At Interest Percent Of Total Investments	8.70%		8.70%		10.60%
Funds withheld at interest	$ 5,614,363		$ 5,614,363		$ 5,761,471
Other Invested Assets Percent Of Cash And Invested Assets	3.40%		3.40%		3.50%
ProceedsFromSaleOfAvailableForSaleEquitySecuritiesSoldAtLoss				31,500
Available-for-sale Equity Securities, Gross Unrealized Loss	$ 0	$ 174	$ 1	$ 1,124
CALIFORNIA
Investment Narrative [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	17.00%		17.00%
TEXAS
Investment Narrative [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	12.90%		12.90%
WASHINGTON
Investment Narrative [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	7.40%		7.40%
CANADA
Investment Narrative [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	2.90%		2.90%
UNITED KINGDOM
Investment Narrative [Line Items]
Mortgage Loans On Real Estate Commercial And Consumer Net Percentage Of Total	0.50%		0.50%

Derivative Instruments (Gross N

Derivative Instruments (Gross Notional Amount and Fair Value of Derivatives Contracts) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Document Period End Date	Sep. 30, 2019
Notional Amount	$ 20,355,622	$ 19,884,691
Carrying Value / Fair Value of Assets	358,455	356,666
Derivative Liability, Fair Value, Gross Liability	1,080,720	990,895
Not Designated as Hedging Instrument
Derivative [Line Items]
Notional Amount	18,528,881	18,044,033
Carrying Value / Fair Value of Assets	288,630	254,381
Derivative Liability, Fair Value, Gross Liability	1,038,638	963,638
Not Designated as Hedging Instrument | Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount	929,963	1,040,588
Carrying Value / Fair Value of Assets	84,306	47,652
Derivative Liability, Fair Value, Gross Liability	2,778	961
Not Designated as Hedging Instrument | Financial Futures
Derivative [Line Items]
Notional Amount	361,030	325,620
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument | Foreign Currency Forwards
Derivative [Line Items]
Notional Amount	125,000	25,000
Carrying Value / Fair Value of Assets	337	0
Derivative Liability, Fair Value, Gross Liability	0	234
Not Designated as Hedging Instrument | Consumer Price Index Swap [Member]
Derivative [Line Items]
Notional Amount	422,068	385,580
Carrying Value / Fair Value of Assets	360	0
Derivative Liability, Fair Value, Gross Liability	33,245	11,384
Not Designated as Hedging Instrument | Credit Default Swaps
Derivative [Line Items]
Notional Amount	1,337,800	1,338,300
Carrying Value / Fair Value of Assets	5,888	6,003
Derivative Liability, Fair Value, Gross Liability	139	1,166
Not Designated as Hedging Instrument | Equity Options
Derivative [Line Items]
Notional Amount	386,536	439,158
Carrying Value / Fair Value of Assets	24,844	42,836
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument | Longevity Swap [Member]
Derivative [Line Items]
Notional Amount	871,920	917,360
Carrying Value / Fair Value of Assets	51,620	47,789
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument | Mortality Swap [Member]
Derivative [Line Items]
Notional Amount	25,000	25,000
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Fair Value, Gross Liability	853	369
Not Designated as Hedging Instrument | Currency Swap [Member]
Derivative [Line Items]
Notional Amount	149,698	149,698
Carrying Value / Fair Value of Assets	0	504
Derivative Liability, Fair Value, Gross Liability	12,454	4,659
Not Designated as Hedging Instrument | Embedded Derivatives In Modified Coinsurance Or Funds Withheld Arrangements
Derivative [Line Items]
Notional Amount	0	0
Carrying Value / Fair Value of Assets	121,275	109,597
Derivative Liability, Fair Value, Gross Liability	0	0
Not Designated as Hedging Instrument | Embedded Derivatives In Indexed Annuity [Member]
Derivative [Line Items]
Notional Amount	0	0
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Fair Value, Gross Liability	779,128	776,940
Not Designated as Hedging Instrument | Embedded Derivatives In Variable Annuity [Member]
Derivative [Line Items]
Notional Amount	0	0
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Fair Value, Gross Liability	210,041	167,925
Not Designated as Hedging Instrument | Synthetic Guaranteed Investment Contracts
Derivative [Line Items]
Notional Amount	13,919,866	13,397,729
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Fair Value, Gross Liability	0	0
Designated As Hedging Instrument
Derivative [Line Items]
Notional Amount	1,826,741	1,840,658
Carrying Value / Fair Value of Assets	69,825	102,285
Derivative Liability, Fair Value, Gross Liability	42,082	27,257
Designated As Hedging Instrument | Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount	435,000	435,000
Carrying Value / Fair Value of Assets	0	0
Derivative Liability, Fair Value, Gross Liability	34,467	27,257
Designated As Hedging Instrument | Foreign Currency Forwards
Derivative [Line Items]
Notional Amount	1,025,548	911,197
Carrying Value / Fair Value of Assets	43,441	50,974
Derivative Liability, Fair Value, Gross Liability	0	0
Designated As Hedging Instrument | Currency Swap [Member]
Derivative [Line Items]
Notional Amount	366,193	494,461
Carrying Value / Fair Value of Assets	26,384	51,311
Derivative Liability, Fair Value, Gross Liability	$ 7,615	$ 0

Derivative Instruments Derivati

Derivative Instruments Derivative Instruments (Fair Value Hedge Attributable to Foreign Currency) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments	$ (5,995)	$ (2,258)	$ (10,422)	$ (5,284)
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	$ 4,088	$ 2,832	$ 4,503	$ 9,666

Derivative Instruments (Current

Derivative Instruments (Current Period Cash Flow Hedges in AOCI (loss) before Taxes) (Details) - Cash Flow Hedging [Member] - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 47,202	$ 14,862	$ (29,043)	$ (22,656)	$ 47,202	$ (29,043)	$ (8,788)	$ (2,619)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	(32,123)		6,671		(54,902)	26,586
Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	38		(50)		19	(270)
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ (255)		$ (234)		$ (1,107)	$ 108

Derivative Instruments (Cash Fl

Derivative Instruments (Cash Flow Hedges) (Details) - Cash Flow Hedging [Member] - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	$ (32,123)		$ 6,671		$ (54,902)	$ 26,586
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(47,202)	$ (14,862)	29,043	$ 22,656	(47,202)	29,043	$ 8,788	$ 2,619
Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(38)		50		(19)	270
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	255		234		1,107	(108)
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	(24,846)		7,490		(46,816)	27,217
Interest Rate Swap [Member] | Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0		0		0	0
Interest Rate Swap [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	255		234		1,107	(108)
Currency Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	(7,277)		(819)		(8,086)	(631)
Currency Swap [Member] | Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	(38)		50		(19)	270
Currency Swap [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 0		$ 0		$ 0	$ 0

Derivative Instruments (Hedges

Derivative Instruments (Hedges of Net Investments in Foreign Operations) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivatives, Fair Value [Line Items]
Net Derivatives Gains (Losses) Deferred in AOCI	[1]	$ 20,357	$ (17,439)	$ (13,232)	$ 22,862
Currency Swap [Member]
Derivatives, Fair Value [Line Items]
Net Derivatives Gains (Losses) Deferred in AOCI	[1]	3,930	(5,877)	(5,563)	11,125
Foreign Exchange Forward [Member]
Derivatives, Fair Value [Line Items]
Net Derivatives Gains (Losses) Deferred in AOCI	[1]	$ 16,427	$ (11,562)	$ (7,669)	$ 11,737
[1]	There were no sales or substantial liquidations of net investments in foreign operations that would have required the reclassification of gains or losses from accumulated other comprehensive income (loss) into investment income during the periods presented.

Derivative Instruments (Non Hed

Derivative Instruments (Non Hedging Derivatives and Embedded Derivatives Effect on Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	$ 48,784	$ (20,017)	$ 69,044	$ (31,059)
Policy acquisition costs and other insurance expenses	(321,855)	(310,639)	(894,081)	(987,817)
Interest credited	226,262	143,292	517,293	333,068
Other revenues	90,335	112,764	291,960	272,020
Gain Loss On Investments Related To Change In Fair Value Of Derivatives Excluding Embedded Derivatives	36,259	(25,258)	38,497	(58,883)
Not Designated as Hedging Instrument
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(42,438)	(20,553)	(42,302)	30,217
Not Designated as Hedging Instrument | Interest Rate Swap [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	38,701	(12,228)	96,079	(47,399)
Not Designated as Hedging Instrument | Financial Futures
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	322	(6,544)	(29,641)	(7,312)
Not Designated as Hedging Instrument | Currency Swap [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	867	0	(4,790)	0
Not Designated as Hedging Instrument | Foreign Currency Forwards
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	337	(58)	571	3
Not Designated as Hedging Instrument | Consumer Price Index Swap [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	(8,235)	(4,223)	(23,898)	(996)
Not Designated as Hedging Instrument | Credit Default Swaps
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	1,961	4,689	21,539	5,371
Not Designated as Hedging Instrument | Equity Options
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	243	(9,793)	(27,269)	(15,207)
Not Designated as Hedging Instrument | Longevity Swap [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Other revenues	2,063	2,426	6,390	6,983
Not Designated as Hedging Instrument | Mortality Swap [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Other revenues	0	473	(484)	(326)
Not Designated as Hedging Instrument | Embedded Derivatives In Modified Coinsurance Or Funds Withheld Arrangements
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	8,508	(2,081)	11,678	20,335
Not Designated as Hedging Instrument | Embedded Derivatives In Indexed Annuity [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Interest credited	(44,972)	25,347	(50,361)	(6,523)
Not Designated as Hedging Instrument | Embedded Derivatives In Variable Annuity [Member]
Income Affect Of Non Hedging Derivatives [Line Items]
Total investment related gains (losses), net	$ (42,233)	$ 32,133	$ (42,116)	$ 62,242

Derivative Instruments (Exposur

Derivative Instruments (Exposure from Credit Derivatives by Rating of the Underlying Credits) (Details) - USD ($) $ in Thousands		9 Months Ended		12 Months Ended
		Sep. 30, 2019		Dec. 31, 2018
Credit Derivatives [Line Items]
Document Period End Date		Sep. 30, 2019
Credit Derivative Current Fair Value	[1]	$ 5,749		$ 4,837
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]	$ 1,337,800		$ 1,338,300
Derivative Average Remaining Maturity	[1],[3]	3 years 10 months 24 days		4 years 8 months 12 days
Standard Poors AAA To A Minus Ratings [Member] | Single Name Credit Default Swaps [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]	$ 1,018		$ 1,953
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]	$ 117,500		$ 152,000
Derivative Average Remaining Maturity	[1],[3]	1 year 7 months 6 days		2 years 2 months 12 days
Standard Poors AAA To A Minus Ratings [Member] | Credit Default Swaps Referencing Indices [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]	$ 342		$ 0
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]	$ 240,000		$ 0
Derivative Average Remaining Maturity	[1],[3]	10 years 2 months 12 days		0 years
Standard Poors AAA To A Minus Ratings [Member] | Credit Default Subtotal [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]	$ 1,360		$ 1,953
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]	$ 357,500		$ 152,000
Derivative Average Remaining Maturity	[1],[3]	7 years 4 months 24 days		2 years 2 months 12 days
Standard Poors BBB Rating [Member] | Single Name Credit Default Swaps [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]	$ 4,103		$ 2,930
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]	$ 337,700		$ 353,700
Derivative Average Remaining Maturity	[1],[3]	2 years		2 years 2 months 12 days
Standard Poors BBB Rating [Member] | Credit Default Swaps Referencing Indices [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]	$ 111		$ (76)
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]	$ 632,600		$ 817,600
Derivative Average Remaining Maturity	[1],[3]	2 years 10 months 24 days		6 years 4 months 24 days
Standard Poors BBB Rating [Member] | Credit Default Subtotal [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]	$ 4,214		$ 2,854
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]	$ 970,300		$ 1,171,300
Derivative Average Remaining Maturity	[1],[3]	2 years 7 months 6 days		5 years 1 month 6 days
Standard & Poor's, BB Rating [Member]
Credit Derivatives [Line Items]
Derivative Average Remaining Maturity	[1]	2 years 8 months 12 days	[3]	8 months 12 days	[2]
Standard & Poor's, BB Rating [Member] | Single Name Credit Default Swaps [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]	$ 175		$ 30
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]	10,000		15,000
Standard & Poor's, BB Rating [Member] | Credit Default Subtotal [Member]
Credit Derivatives [Line Items]
Credit Derivative Current Fair Value	[1]	175		30
Maximum Potential Future Exposure on Credit Risk Derivatives	[1],[2]	$ 10,000		$ 15,000
[1]	The rating agency designations are based on ratings from Standard and Poor’s (“S&P”).
[2]	Assumes the value of the referenced credit obligations is zero.
[3]	The weighted average years to maturity of the credit default swaps is calculated based on weighted average notional amounts.

Derivative Instruments (Derivat

Derivative Instruments (Derivative Instruments Offsetting Balance Sheet) (Details) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Derivative Assets [Abstract]
Derivative Fair Value Of Free Standing Derivative Asset		$ 237,180	$ 247,069
Gross Amounts Offset in the Balance Sheet		(43,461)	(18,581)
Net Amounts Presented in the Balance Sheet		193,719	228,488
Derivative Asset, Fair Value of Collateral	[1]	0	0
Gross Amounts Not Offset in the Balance Sheet - Cash Collateral Pledged/Received		(205,890)	(235,611)
Net Amount		(12,171)	(7,123)
Derivative Liabilities [Abstract]
Derivative Fair Value Of Free Standing Derivative Liability		91,551	46,030
Gross Amounts Offset in the Balance Sheet		(43,461)	(18,581)
Net Amounts Presented in the Balance Sheet		48,090	27,449
Gross Amounts Not Offset in the Balance Sheet - Financial Instruments	[1]	(81,090)	(71,376)
Gross Amounts Not Offset in the Balance Sheet - Cash Collateral Pledged/Received		(60,080)	(24,080)
Net Amount		$ (93,080)	$ (68,007)
[1]	Includes initial margin posted to a central clearing partner.

Derivative Instruments (Narrati

Derivative Instruments (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Cumulative Foreign Currency Translation Gain Loss Recorded In Accumulated Other Comprehensive Income Loss For Terminated Net Investment In Foreign Operations Hedges	$ 187.8	$ 201
Investment Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	0.1
Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ (0.8)

Fair Value of Assets and Liab_3

Fair Value of Assets and Liabilities Fair Value of Assets and Liabilities (Balances of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	$ 49,481,267	$ 39,992,346
Equity Method Investments, Fair Value Disclosure	134,453	82,197
Funds withheld at interest embedded derivatives	121,275	109,597
Cash and cash equivalents	927,175	485,167
Short-term investments	89,130	105,991
Investments, Fair Value Disclosure	394,376	378,469
Other Assets, Fair Value Disclosure	51,620	47,789
Assets, Fair Value Disclosure	51,199,296	41,201,556
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	989,170	944,865
Liabilities Fair Value Disclosure
Financial Liabilities Fair Value Disclosure	1,037,260	972,314
Interest Rate Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	73,085	37,976
Liabilities Fair Value Disclosure
Other liabilities	(26,024)	(18,542)
Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	(12,454)
Foreign Currency Forwards
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	43,654	50,740
Liabilities Fair Value Disclosure
Other liabilities	124
Consumer Price Index Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	(32,885)	(11,384)
Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	252,277	197,770
Credit Default Swaps
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	(7,174)	4,466
Liabilities Fair Value Disclosure
Other liabilities	12,923	371
Equity Option [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	6,150	36,206
Liabilities Fair Value Disclosure
Other liabilities	18,694	6,630
Currency Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	26,384	51,311
Liabilities Fair Value Disclosure
Other liabilities	(7,615)	(4,155)
Mortality Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	(853)	(369)
Corporate Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	30,353,219	23,982,119
Canadian and Canadian provincial governments
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	4,633,219	3,892,385
Residential mortgage-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	2,439,842	1,869,221
Asset-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	2,822,635	2,149,204
Assets, Fair Value Disclosure	102,027	77,842
Commercial Mortgage Backed Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,782,218	1,419,034
US Government Agencies Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,668,505	2,185,874
Assets, Fair Value Disclosure	17,141	18,025
US States and Political Subdivisions Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,190,103	752,194
Debt Security, Government, Non-US [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	4,591,526	3,742,315
Fair Value Inputs Level 1 Member
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,541,294	2,067,529
Equity Method Investments, Fair Value Disclosure	86,968	48,737
Funds withheld at interest embedded derivatives	0	0
Cash and cash equivalents	922,291	473,509
Short-term investments	17,375	4,989
Investments, Fair Value Disclosure	197,195	196,781
Other Assets, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	2,765,123	2,791,545
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	0	0
Liabilities Fair Value Disclosure
Financial Liabilities Fair Value Disclosure	0	0
Fair Value Inputs Level 1 Member | Interest Rate Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 1 Member | Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	0
Fair Value Inputs Level 1 Member | Foreign Currency Forwards
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Liabilities Fair Value Disclosure
Other liabilities	0
Fair Value Inputs Level 1 Member | Consumer Price Index Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 1 Member | Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	197,195	196,781
Fair Value Inputs Level 1 Member | Credit Default Swaps
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 1 Member | Equity Option [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 1 Member | Currency Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 1 Member | Mortality Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 1 Member | Corporate Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0	0
Fair Value Inputs Level 1 Member | Canadian and Canadian provincial governments
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0	0
Fair Value Inputs Level 1 Member | Residential mortgage-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0	0
Fair Value Inputs Level 1 Member | Asset-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0	0
Fair Value Inputs Level 1 Member | Commercial Mortgage Backed Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0	0
Fair Value Inputs Level 1 Member | US Government Agencies Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,541,294	2,067,529
Fair Value Inputs Level 1 Member | US States and Political Subdivisions Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0	0
Fair Value Inputs Level 1 Member | Debt Security, Government, Non-US [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	0	0
Fair Value Inputs Level 2 Member
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	45,244,476	35,930,086
Equity Method Investments, Fair Value Disclosure	0	0
Funds withheld at interest embedded derivatives	0	0
Cash and cash equivalents	4,884	11,658
Short-term investments	68,898	98,774
Investments, Fair Value Disclosure	197,181	181,688
Other Assets, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	45,515,439	36,222,206
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	0	0
Liabilities Fair Value Disclosure
Financial Liabilities Fair Value Disclosure	47,237	27,080
Fair Value Inputs Level 2 Member | Interest Rate Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	73,085	37,976
Liabilities Fair Value Disclosure
Other liabilities	(26,024)	(18,542)
Fair Value Inputs Level 2 Member | Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	(12,454)
Fair Value Inputs Level 2 Member | Foreign Currency Forwards
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	43,654	50,740
Liabilities Fair Value Disclosure
Other liabilities	124
Fair Value Inputs Level 2 Member | Consumer Price Index Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	(32,885)	(11,384)
Fair Value Inputs Level 2 Member | Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	55,082	989
Fair Value Inputs Level 2 Member | Credit Default Swaps
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	(7,174)	4,466
Liabilities Fair Value Disclosure
Other liabilities	12,923	371
Fair Value Inputs Level 2 Member | Equity Option [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	6,150	36,206
Liabilities Fair Value Disclosure
Other liabilities	18,694	6,630
Fair Value Inputs Level 2 Member | Currency Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	26,384	51,311
Liabilities Fair Value Disclosure
Other liabilities	(7,615)	(4,155)
Fair Value Inputs Level 2 Member | Mortality Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 2 Member | Corporate Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	28,547,959	22,651,194
Fair Value Inputs Level 2 Member | Canadian and Canadian provincial governments
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	3,942,376	3,364,261
Fair Value Inputs Level 2 Member | Residential mortgage-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	2,416,762	1,862,366
Fair Value Inputs Level 2 Member | Asset-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	2,719,526	2,053,632
Fair Value Inputs Level 2 Member | Commercial Mortgage Backed Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,752,250	1,419,012
Fair Value Inputs Level 2 Member | US Government Agencies Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	110,070	100,320
Fair Value Inputs Level 2 Member | US States and Political Subdivisions Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,180,150	741,992
Fair Value Inputs Level 2 Member | Debt Security, Government, Non-US [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	4,575,383	3,737,309
Fair Value Inputs Level 3 Member
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	2,695,497	1,994,731
Equity Method Investments, Fair Value Disclosure	47,485	33,460
Funds withheld at interest embedded derivatives	121,275	109,597
Cash and cash equivalents	0	0
Short-term investments	2,857	2,228
Investments, Fair Value Disclosure	0	0
Other Assets, Fair Value Disclosure	51,620	47,789
Assets, Fair Value Disclosure	2,918,734	2,187,805
Fair Value Measured On Recurring Basis Guaranteed Interest Contracts Embedded Derivatives	989,170	944,865
Liabilities Fair Value Disclosure
Financial Liabilities Fair Value Disclosure	990,023	945,234
Fair Value Inputs Level 3 Member | Interest Rate Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 3 Member | Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	0
Fair Value Inputs Level 3 Member | Foreign Currency Forwards
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Liabilities Fair Value Disclosure
Other liabilities	0
Fair Value Inputs Level 3 Member | Consumer Price Index Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 3 Member | Fair Value Option Contractholder Directed Unit Linked Investments [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Fair Value Inputs Level 3 Member | Credit Default Swaps
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 3 Member | Equity Option [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 3 Member | Currency Swap [Member]
Assets Fair Value Disclosure
Investments, Fair Value Disclosure	0	0
Liabilities Fair Value Disclosure
Other liabilities	0	0
Fair Value Inputs Level 3 Member | Mortality Swap [Member]
Liabilities Fair Value Disclosure
Other liabilities	(853)	(369)
Fair Value Inputs Level 3 Member | Corporate Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	1,805,260	1,330,925
Fair Value Inputs Level 3 Member | Canadian and Canadian provincial governments
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	690,843	528,124
Fair Value Inputs Level 3 Member | Residential mortgage-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	23,080	6,855
Fair Value Inputs Level 3 Member | Asset-backed securities
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	103,109	95,572
Fair Value Inputs Level 3 Member | Commercial Mortgage Backed Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	29,968	22
Fair Value Inputs Level 3 Member | US Government Agencies Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	17,141	18,025
Fair Value Inputs Level 3 Member | US States and Political Subdivisions Debt Securities [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	9,953	10,202
Fair Value Inputs Level 3 Member | Debt Security, Government, Non-US [Member]
Assets Fair Value Disclosure
Fixed maturity securities, available-for-sale	$ 16,143	$ 5,006

Fair Value of Assets and Liab_4

Fair Value of Assets and Liabilities Fair Value of Assets and Liabilities (Quantitative Information for Level 3 Inputs) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Document Period End Date	Sep. 30, 2019
Assets, Fair Value Disclosure	$ 51,199,296	$ 41,201,556
Corporate Debt Securities [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 888,946	$ 642,647
Corporate Debt Securities [Member] | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.01	0.01
Corporate Debt Securities [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.05	0.05
Corporate Debt Securities [Member] | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0	0
Asset-backed securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 102,027	$ 77,842
Asset-backed securities | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.01	0.01
Asset-backed securities | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.04	0.01
Asset-backed securities | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0	0
Longevity Swap [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 51,620	$ 47,789
US Government Agencies Debt Securities [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 17,141	$ 18,025
US Government Agencies Debt Securities [Member] | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.01	0.01
US Government Agencies Debt Securities [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.01	0.01
US Government Agencies Debt Securities [Member] | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0	0
Debt Security, Corporate, Non-US [Member] | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.01	0.01
Debt Security, Corporate, Non-US [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.01	0.01
Debt Security, Corporate, Non-US [Member] | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0	0.01
Foreign Government Debt [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 16,143	$ 5,006
Equity securities | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 30,681	$ 25,007
Equity securities | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity Securities, FV-NI, Measurement Input	0.04	0.04
Equity securities | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity Securities, FV-NI, Measurement Input	0.04	0.04
Equity securities | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity Securities, FV-NI, Measurement Input	0.04	0.04
Funds Withheld At Interest Embedded Derivatives [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value Disclosure	$ 121,275	$ 109,597
Embedded Derivatives In Indexed Annuity [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 779,128	$ 776,940
Embedded Derivatives In Indexed Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.02	0.02
Embedded Derivatives In Indexed Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.04	0.04
Embedded Derivatives In Indexed Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.02	0.02
Embedded Derivatives In Variable Annuity [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 210,041	$ 167,925
Mortality Swap [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 853	$ 369
Measurement Input, Mortality Rate [Member] | Longevity Swap [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.02	0.02
Measurement Input, Mortality Rate [Member] | Longevity Swap [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	1	1
Measurement Input, Mortality Rate [Member] | Longevity Swap [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0	0
Measurement Input, Mortality Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0.02	0.02
Measurement Input, Mortality Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	1	1
Measurement Input, Mortality Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0	0
Measurement Input, Mortality Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.02	0.02
Measurement Input, Mortality Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	1	1
Measurement Input, Mortality Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0	0
Measurement Input, Mortality Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.01	0.01
Measurement Input, Mortality Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	1	1
Measurement Input, Mortality Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0	0
Measurement Input, Mortality Rate [Member] | Mortality Swap [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.01	0.01
Measurement Input, Mortality Rate [Member] | Mortality Swap [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	1	1
Measurement Input, Mortality Rate [Member] | Mortality Swap [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0	0
Measurement Input, Lapse Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0.12	0.10
Measurement Input, Lapse Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0.35	0.35
Measurement Input, Lapse Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0	0
Measurement Input, Lapse Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.12	0.10
Measurement Input, Lapse Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.35	0.35
Measurement Input, Lapse Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0	0
Measurement Input, Lapse Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.05	0.05
Measurement Input, Lapse Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.25	0.25
Measurement Input, Lapse Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0	0
Measurement Input, Withdrawal Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0.03	0.03
Measurement Input, Withdrawal Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0.05	0.05
Measurement Input, Withdrawal Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0	0
Measurement Input, Withdrawal Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.03	0.03
Measurement Input, Withdrawal Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.05	0.05
Measurement Input, Withdrawal Rate [Member] | Embedded Derivatives In Indexed Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0	0
Measurement Input, Withdrawal Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.05	0.05
Measurement Input, Withdrawal Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.07	0.07
Measurement Input, Withdrawal Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0	0
Measurement Input, Counterparty Credit Risk [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0.01	0.01
Measurement Input, Counterparty Credit Risk [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0.05	0.05
Measurement Input, Counterparty Credit Risk [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0	0
Measurement Input, Counterparty Credit Risk [Member] | Embedded Derivatives In Variable Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.01	0.01
Measurement Input, Counterparty Credit Risk [Member] | Embedded Derivatives In Variable Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.05	0.05
Measurement Input, Counterparty Credit Risk [Member] | Embedded Derivatives In Variable Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0	0
Measurement Input, Long-term Revenue Growth Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.12	0.13
Measurement Input, Long-term Revenue Growth Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0.27	0.27
Measurement Input, Long-term Revenue Growth Rate [Member] | Embedded Derivatives In Variable Annuity [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Liability, Measurement Input	0	0
Measurement Input Crediting Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Weighted Average [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0.02	0.02
Measurement Input Crediting Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Maximum [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0.04	0.04
Measurement Input Crediting Rate [Member] | Funds Withheld At Interest Embedded Derivatives [Member] | Minimum [Member] | Valuation, Income Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Embedded Derivative Asset, Measurement Input	0.02	0.02
Measurement Input, EBITDA Multiple [Member] | Corporate Debt Securities [Member] | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	5.8	6.5
Measurement Input, EBITDA Multiple [Member] | Corporate Debt Securities [Member] | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	6.1	7.5
Measurement Input, EBITDA Multiple [Member] | Corporate Debt Securities [Member] | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	5.2	5.9
Measurement Input, EBITDA Multiple [Member] | Equity securities | Weighted Average [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity Securities, FV-NI, Measurement Input	7.9	7.9
Measurement Input, EBITDA Multiple [Member] | Equity securities | Maximum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity Securities, FV-NI, Measurement Input	9.3	12.3
Measurement Input, EBITDA Multiple [Member] | Equity securities | Minimum [Member] | Valuation, Market Approach [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Equity Securities, FV-NI, Measurement Input	6.9	6.9
Measurement Input Mortality Improvement [Member] | Longevity Swap [Member] | Weighted Average [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.03	0.03
Measurement Input Mortality Improvement [Member] | Longevity Swap [Member] | Maximum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	0.10	0.10
Measurement Input Mortality Improvement [Member] | Longevity Swap [Member] | Minimum [Member] | Valuation Technique, Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Instrument, Measurement Input	(0.10)	(0.10)

Fair Value of Assets and Liab_5

Fair Value of Assets and Liabilities Fair Value of Assets and Liabilities (Changes in Level 3 Assets and Liabilities) (Details) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018		Jun. 30, 2018	Sep. 30, 2019		Sep. 30, 2018
Corporate Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		$ 1,644,364	$ 1,367,154			$ 1,330,925		$ 1,337,272
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		17,090	(4,858)			53,222		(35,532)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	214,025	123,808			604,897		379,476
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	(34,363)	(62,047)			(59,000)		(79,316)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	(63,216)	(101,868)			(166,865)		(245,342)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		27,042	2,782			43,083		9,948
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	(69,119)			1,495		(106,847)
Fair Value, end of period		1,805,260	1,255,935		$ 1,367,154	1,805,260		1,255,935
Corporate Debt Securities [Member] | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		318	(156)			478		(822)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		344	(180)			580		(845)
Corporate Debt Securities [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings			239			15		(2,902)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)			(1,430)					(4,571)
Canadian Provincial Governments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		671,027	572,698			528,124		593,942
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		16,103	(27,476)			151,944		(55,632)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	0			0		0
Fair Value, end of period		690,843	548,742		572,698	690,843		548,742
Canadian Provincial Governments [Member] | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		3,713	3,520			10,775		10,432
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		3,713	3,520			10,775		10,432
Canadian Provincial Governments [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings			0			0		0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)			0					0
Residential mortgage-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		16,032	54,839			6,855		107,882
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		150	(1)			221		(1,782)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	0	0			3,018		45,328
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	0	0			0		(4,961)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	(2,370)	(3)			(3,945)		(4,538)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		15,421	0			23,103		3,031
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		(6,040)	(54,838)			6,040		(145,140)
Fair Value, end of period		23,080	0		54,839	23,080		0
Residential mortgage-backed securities | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		(113)	3			(132)		(132)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		(113)	0			(132)		0
Residential mortgage-backed securities | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings			0			0		312
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)			0					0
Asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		110,322	70,686			95,572		123,474
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		(51)	(130)			1,972		(821)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	10,764	11,099			50,511		22,099
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	0	(462)			0		(462)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	(17,929)	(24,166)			(45,081)		(46,449)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0	64,009			0		68,977
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	(38,915)			0		(86,163)
Fair Value, end of period		103,109	82,767		70,686	103,109		82,767
Asset-backed securities | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		3	20			25		202
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		3	13			24		187
Asset-backed securities | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings			626			110		1,910
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)			0					0
US States and Political Subdivisions Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		9,855	16,505			10,202		41,203
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		132			(544)	164		46
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	0			0	0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	0				0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	(40)			(37)	(429)		(158)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0			9,859	0		9,859
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3					12,144			37,309
Fair Value, end of period		9,953	13,645		16,505	9,953		13,645
US States and Political Subdivisions Debt Securities [Member] | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		6			6	16		4
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		6			6	16		3
US States and Political Subdivisions Debt Securities [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0				0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0				0
Debt Security, Government, Non-US [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		15,686	5,044			5,006		5,092
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		457			(32)	1,137		(80)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	0			0	10,000		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	0				0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	0			0	0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0			0	0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3					0			0
Fair Value, end of period		16,143	5,012		5,044	16,143		5,012
Debt Security, Government, Non-US [Member] | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0			0	0		0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0			0	0		0
Debt Security, Government, Non-US [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0				0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0				0
US Government Agencies Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		17,406	20,735			18,025		22,511
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		79			(122)	668		(635)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	104			120	290		334
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]					0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	(358)			(374)	(1,577)		(1,634)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3					0			0
Fair Value, end of period		17,141	20,252		20,735	17,141		20,252
US Government Agencies Debt Securities [Member] | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		(90)			(107)	(265)		(324)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		(90)			(107)	(265)		(325)
US Government Agencies Debt Securities [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0				0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0				0
Commercial Mortgage Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		19	1,867			22		3,234
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		(975)			7	(975)		(56)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	1,155			0	1,155		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	0				0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	(3)			(1)	(6)		(4)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		29,772			1,752	29,772		1,752
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3					1,843			3,144
Fair Value, end of period		29,968	1,782		1,867	29,968		1,782
Commercial Mortgage Backed Securities [Member] | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0			0	0		0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0			0	0		0
Commercial Mortgage Backed Securities [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0				0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0				0
US Treasury and Government [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0			0	0		0
Funds Withheld At Interest Embedded Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		112,767	144,610			109,597		122,194
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3								0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	0			0		0
Fair Value, end of period		121,275	142,529		144,610	121,275		142,529
Funds Withheld At Interest Embedded Derivatives [Member] | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0				0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0				0
Funds Withheld At Interest Embedded Derivatives [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		8,508	(2,081)			11,678		20,335
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		8,508	(2,081)			11,678		20,335
Funds Withheld At Interest Embedded Derivatives [Member] | Interest Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0	0			0		0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0	0			0		0
Funds Withheld At Interest Embedded Derivatives [Member] | Other Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0	0			0		0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0	0			0		0
Longevity Swap [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		51,755	43,971			47,789		40,659
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		(2,198)	(307)			(2,559)		(1,552)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3								0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		0	0			0		0
Fair Value, end of period		51,620	46,090		43,971	51,620		46,090
Longevity Swap [Member] | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0				0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0				0
Longevity Swap [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0	0			0		0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0	0			0		0
Longevity Swap [Member] | Interest Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0	0			0		0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0	0			0		0
Longevity Swap [Member] | Other Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		2,063	2,426			6,390		6,983
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		2,063	2,426			6,390		6,983
Interest Sensitive Contract Liabilities Embedded Derivatives [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3								0
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		908,491	(928,797)			(944,865)		(1,014,228)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)		0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases	[1]	16,887	(4,231)			(12,904)		(16,946)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	[1]	23,413	20,044			61,076		56,210
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3		0	0			0		0
Fair Value, end of period		(989,170)	(906,199)		(928,797)	(989,170)		(906,199)
Interest Sensitive Contract Liabilities Embedded Derivatives [Member] | Investment Income [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings		0				0
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)		0				0
Interest Sensitive Contract Liabilities Embedded Derivatives [Member] | Gain (Loss) on Investments [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings		42,233	(32,133)			42,116		(62,242)
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)		44,965	(30,433)			48,041		(56,808)
Interest Sensitive Contract Liabilities Embedded Derivatives [Member] | Interest Income [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings		44,972	(25,348)			(50,361)		6,523
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)		68,385	45,393			111,436		49,688
Interest Sensitive Contract Liabilities Embedded Derivatives [Member] | Other Income [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings		0	0			0		0
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)		0	0			0		0
Mortality Swap [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3								0
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		853	782			369		1,683
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)		0	1			0		1
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases	[1]	0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	[1]	0	0			0		1,700
Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3		0	0			0		0
Fair Value, end of period		(853)	(308)		782	(853)		(308)
Mortality Swap [Member] | Investment Income [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings		0				0
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)		0				0
Mortality Swap [Member] | Gain (Loss) on Investments [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings		0	0			0		0
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)		0	0			0		0
Mortality Swap [Member] | Interest Income [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings		0	0			0		0
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)		0	0			0		0
Mortality Swap [Member] | Other Income [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings		0	(473)			484		326
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss)		0	473			(484)		(326)
Cash and Cash Equivalents [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period						0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)						0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]					19
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]					0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]					0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3						19
Fair Value, end of period		0				0
Cash and Cash Equivalents [Member] | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings						0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)						0
Cash and Cash Equivalents [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings						0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)						0
Cash and Cash Equivalents [Member] | Interest Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings						0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)						0
Cash and Cash Equivalents [Member] | Other Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings						0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)						0
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		44,807	42,937			33,460		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		0	0			0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	821	863			6,621		13,111
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales		880	5,847	[1]		880	[1]	6,416	[1]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	0	0			0		48
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3		0				0		38,905
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3			0					0
Fair Value, end of period		47,485	43,485		42,937	47,485		43,485
Equity securities | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0				0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0				0
Equity securities | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		2,737	5,532			8,284		(2,067)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		2,638	2,178			8,185		(5,527)
Equity securities | Interest Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings			0					0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)			0					0
Equity securities | Other Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period								0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings			0					0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)			0
Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period		28,387	3,217			2,228		3,096
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)		(266)	47			(134)		1
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	[1]	1,656	1,721			29,664		2,202
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales	[1]	0	0			(1,517)		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	[1]	(11)	0			(558)		(314)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3								0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3		27,042	2,782			27,064		2,782
Fair Value, end of period		2,857	2,203		$ 3,217	2,857		2,203
Short-term Investments [Member] | Investment Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		133				221
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		133				221
Short-term Investments [Member] | Gain (Loss) on Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0	0			17		0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0	0			0		0
Short-term Investments [Member] | Interest Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0	0			0		0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		0	0			0		0
Short-term Investments [Member] | Other Income [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings		0	0			0		0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)		$ 0	$ 0			$ 0		$ 0
[1]	The amount reported within purchases, sales and settlements is the purchase price (for purchases) and the sales/settlement proceeds (for sales and settlements) based upon the actual date purchased or sold/settled. Items purchased and sold/settled in the same period are excluded from the rollforward. The Company had no issuances during the period.

Fair Value of Assets and Liab_6

Fair Value of Assets and Liabilities Fair Value of Assets and Liabilities (Fair Value Assets Measured on Non-Recurring Basis) (Details) - Partnership Interest [Member] - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assets Carrying Value Prior To Impairment	[1]	$ 17,785	$ 2,246	$ 17,785	$ 2,246
Fair Value Assets Gains Losses	[1]	$ (3,537)	$ (1,860)	$ (8,586)	$ (1,860)
[1]	The impaired limited partnership interests presented above were accounted for using the cost method. Impairments on these cost method investments were recognized at estimated fair value determined using the net asset values of the Company’s ownership interest as provided in the financial statements of the investees. The market for these investments has limited activity and price transparency.

Fair Value of Assets and Liab_7

Fair Value of Assets and Liabilities Fair Value of Assets and Liabilities (Financial Instruments where Carrying Amounts and Fair Values May Differ) (Details) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Assets
Mortgage loans on real estate (net of valuation allowances)		$ 5,647,265	$ 4,966,298
Policy loans		1,289,868	1,344,980
Funds withheld at interest		5,614,363	5,761,471
Cash and cash equivalents		2,635,596	1,889,733	$ 1,730,489	$ 1,303,524
Short-term investments		107,503	142,598
Other invested assets		2,215,275	1,915,297
Accrued investment income		520,301	427,893
Liabilities
Interest-sensitive contract liabilities		22,345,126	18,004,526
Long-term debt		3,381,406	2,787,873
Collateral finance and securitization notes		610,246	681,961
Reported Value Measurement [Member]
Assets
Mortgage loans on real estate (net of valuation allowances)	[1]	5,647,265	4,966,298
Policy loans	[1]	1,289,868	1,344,980
Funds withheld at interest	[1]	5,476,148	5,655,055
Cash and cash equivalents	[1]	1,708,421	1,404,566
Short-term investments	[1]	18,373	36,607
Other invested assets	[1]	1,147,167	945,731
Accrued investment income	[1]	520,301	427,893
Liabilities
Interest-sensitive contract liabilities	[1]	18,747,630	14,547,436
Long-term debt	[1]	3,381,406
Debt, Long-term and Short-term, Combined Amount	[1]		2,787,873
Collateral finance and securitization notes	[1]	610,246	681,961
Estimate of Fair Value Measurement [Member]
Assets
Mortgage loans on real estate (net of valuation allowances)		5,936,051	4,917,416
Policy loans		1,289,868	1,344,980
Funds withheld at interest		5,873,575	5,802,518
Cash and cash equivalents		1,708,421	1,404,566
Short-term investments		18,373	36,607
Other invested assets		1,205,284	941,449
Accrued investment income		520,301	427,893
Liabilities
Interest-sensitive contract liabilities		20,446,240	14,611,011
Long-term Debt, Fair Value		3,564,595
Debt, Long-term and Short-term, Combined Amount			2,752,047
Collateral finance and securitization notes		561,011	626,731
Estimate of Fair Value Measurement [Member] | Fair Value Inputs Level 1 Member
Assets
Mortgage loans on real estate (net of valuation allowances)		0	0
Policy loans		0	0
Funds withheld at interest		0	0
Cash and cash equivalents		1,708,421	1,404,566
Short-term investments		18,373	36,607
Other invested assets		5,208	4,640
Accrued investment income		0	0
Liabilities
Interest-sensitive contract liabilities		0	0
Long-term Debt, Fair Value		0
Debt, Long-term and Short-term, Combined Amount			0
Collateral finance and securitization notes		0	0
Estimate of Fair Value Measurement [Member] | Fair Value Inputs Level 2 Member
Assets
Mortgage loans on real estate (net of valuation allowances)		0	0
Policy loans		1,289,868	1,344,980
Funds withheld at interest		0	0
Cash and cash equivalents		0	0
Short-term investments		0	0
Other invested assets		82,360	83,203
Accrued investment income		520,301	427,893
Liabilities
Interest-sensitive contract liabilities		0	0
Long-term Debt, Fair Value		0
Debt, Long-term and Short-term, Combined Amount			0
Collateral finance and securitization notes		0	0
Estimate of Fair Value Measurement [Member] | Fair Value Inputs Level 3 Member
Assets
Mortgage loans on real estate (net of valuation allowances)		5,936,051	4,917,416
Policy loans		0	0
Funds withheld at interest		5,873,575	5,802,518
Cash and cash equivalents		0	0
Short-term investments		0	0
Other invested assets		737,064	477,214
Accrued investment income		0	0
Liabilities
Interest-sensitive contract liabilities		20,446,240	14,611,011
Long-term Debt, Fair Value		3,564,595
Debt, Long-term and Short-term, Combined Amount			2,752,047
Collateral finance and securitization notes		561,011	626,731
Estimate of Fair Value Measurement [Member] | Fair Value Measured at Net Asset Value Per Share [Member]
Assets
Mortgage loans on real estate (net of valuation allowances)		0	0
Policy loans		0	0
Funds withheld at interest		0	0
Cash and cash equivalents		0	0
Short-term investments		0	0
Other invested assets		380,652	376,392
Accrued investment income		0	0
Liabilities
Interest-sensitive contract liabilities		0	0
Long-term Debt, Fair Value		0
Debt, Long-term and Short-term, Combined Amount			0
Collateral finance and securitization notes		$ 0	$ 0
[1]	Carrying values presented herein may differ from those in the Company’s condensed consolidated balance sheets because certain items within the respective financial statement captions may be measured at fair value on a recurring basis.

Fair Value of Assets and Liab_8

Fair Value of Assets and Liabilities Fair Value of Assets and Liabilities (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Sep. 30, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Document Period End Date		Sep. 30, 2019
Equity securities
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	$ 0	$ 0	$ 38,905

Segment Information (Total Reve

Segment Information (Total Revenues of Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 3,627,565	$ 3,227,531	$ 10,515,004	$ 9,597,146
Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,992,538	1,838,638	5,673,797	5,335,779
CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	349,055	308,130	1,027,033	947,514
EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	494,910	448,723	1,471,822	1,403,861
Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	731,588	594,202	2,152,263	1,817,099
Corporate and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	59,474	37,838	190,089	92,893
Life Insurance Product Line [Member] | Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,609,866	1,547,790	4,735,208	4,601,631
Life Insurance Product Line [Member] | CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	324,851	295,962	955,326	910,480
Life Insurance Product Line [Member] | EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	378,110	357,059	1,131,615	1,123,379
Life Insurance Product Line [Member] | Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	685,886	578,035	1,992,475	1,763,094
Nontraditional Long-Duration Contracts [Member] | Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	382,672	290,848	938,589	734,148
Nontraditional Long-Duration Contracts [Member] | CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	24,204	12,168	71,707	37,034
Nontraditional Long-Duration Contracts [Member] | EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	116,800	91,664	340,207	280,482
Nontraditional Long-Duration Contracts [Member] | Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 45,702	$ 16,167	$ 159,788	$ 54,005

Segment Information (Income Los

Segment Information (Income Loss Before Provision for Income Tax of Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	$ 347,090	$ 322,661	$ 823,731	$ 707,874
Americas [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	231,418	203,401	473,542	428,080
CANADA
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	46,792	22,795	148,491	75,042
EMEA [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	86,588	74,575	208,324	200,997
Asia Pacific [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	23,339	62,213	102,739	152,121
Corporate and Other [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	(41,047)	(40,323)	(109,365)	(148,366)
Life Insurance Product Line [Member] | Americas [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	112,542	116,328	179,371	191,198
Life Insurance Product Line [Member] | CANADA
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	43,684	21,149	140,222	66,661
Life Insurance Product Line [Member] | EMEA [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	25,342	18,370	56,887	40,259
Life Insurance Product Line [Member] | Asia Pacific [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	21,453	62,007	92,852	143,756
Nontraditional Long-Duration Contracts [Member] | Americas [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	118,876	87,073	294,171	236,882
Nontraditional Long-Duration Contracts [Member] | CANADA
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	3,108	1,646	8,269	8,381
Nontraditional Long-Duration Contracts [Member] | EMEA [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	61,246	56,205	151,437	160,738
Nontraditional Long-Duration Contracts [Member] | Asia Pacific [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	$ 1,886	$ 206	$ 9,887	$ 8,365

Segment Information (Total Asse

Segment Information (Total Assets of Reportable Segments) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 75,773,985	$ 64,535,245
Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	44,557,518	39,106,169
CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	4,330,131	4,354,792
EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	9,868,899	8,380,703
Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	8,112,476	6,861,723
Corporate and Other [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	8,904,961	5,831,858
Life Insurance Product Line [Member] | Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	19,035,387	19,235,781
Life Insurance Product Line [Member] | CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	4,248,447	4,200,792
Life Insurance Product Line [Member] | EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,774,565	3,643,174
Life Insurance Product Line [Member] | Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	6,440,974	5,680,978
Nontraditional Long-Duration Contracts [Member] | Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	25,522,131	19,870,388
Nontraditional Long-Duration Contracts [Member] | CANADA
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	81,684	154,000
Nontraditional Long-Duration Contracts [Member] | EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	6,094,334	4,737,529
Nontraditional Long-Duration Contracts [Member] | Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 1,671,502	$ 1,180,745

Commitments, Contingencies an_3

Commitments, Contingencies and Guarantees (Commitments to Fund Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Limited Partner [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 619,582	$ 523,903
Commercial Loan [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	111,110	22,605
Bank Loans [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	188,648	137,076
Equity Release Mortgages [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Fair Value Disclosure, Off-balance Sheet Risks, Face Amount, Liability	$ 44,910	$ 264,858

Commitments, Contingencies an_4

Commitments, Contingencies and Guarantees (Maximum Potential Obligation) (Details) $ in Millions	Sep. 30, 2019USD ($)
Commitment Period Two Thousand Twenty Three [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 500
Commitment Period Two Thousand Thirty Four [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	2,000
Commitment Period Two Thousand Thirty Five [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	1,314.2
Commitment Period Two Thousand Thirty Six [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	2,658
Commitment Period Two Thousand Thirty Seven [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	5,750
Commitment Period Two Thousand Thirty Eight [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	1,800
Commitment Period Two Thousand Thirty Nine [Member]
Other Commitments [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 1,750

Commitments, Contingencies an_5

Commitments, Contingencies and Guarantees (Guarantees Issued) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Insurance Treaty Guarantee [Member]
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$ 1,764,146	$ 1,392,352
Insurance Treaty Guarantee Net Of Assets Held In Trust [Member]
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	902,008	1,291,445
Guarantee Of Borrowed Securities [Member]
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	273,295	269,980
Product Financing Arrangement [Member]
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	41,246	61,273
Guarantee Of Lease Obligations [Member]
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$ 0	$ 392

Income Tax (Provision for Incom

Income Tax (Provision for Income Tax Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount	$ 72,889	$ 67,759	$ 172,984	$ 148,654
Tax Adjustments, Settlements, and Unusual Provisions	0	664	0	(2,685)
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	0	(58,949)	0	(59,139)
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	84	7,537	1,373	8,795
Income Tax Reconciliation Foreign Income Tax Basis Differential	(9,550)	(2,371)	(30,626)	(9,264)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount	27,721	(5,334)	50,607	5,357
Effective Income Tax Rate Reconciliation, Tax Contingency, Domestic, Amount	3,259	1,851	6,223	650
Income Tax Reconciliation Change In Foreign Enacted Tax Rate	116	(166)	(1,621)	30
Income Tax Reconciliation SubpartF	(26)	(99)	440	211
Effective Income Tax Rate Reconciliation, Tax Credit, Foreign, Amount	(651)	(544)	(759)	(1,003)
Effective Income Tax Rate Reconciliation Global Intangible Low Taxed Income	0	7,624	0	11,916
Effective Income Tax Rate Reconciliation, Equity in Earnings (Losses) of Unconsolidated Subsidiary, Amount	1,034	817	6,189	5,067
Effective Income Tax Rate Reconciliation, Prior Year Income Taxes, Amount	(8,362)	4,213	(4,400)	4,108
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	(121)	94	729	(492)
Income Tax Expense (Benefit)	$ 84,325	$ 21,462	$ 188,761	$ 102,071
Effective Income Tax Rate Reconciliation, Percent	24.30%	6.70%	22.90%	14.40%

Income Tax Income Tax (Narrativ

Income Tax Income Tax (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax [Abstract]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 0	$ 58,949	$ 0	$ 59,139

Employee Benefit Plans (Defined

Employee Benefit Plans (Defined Benefit Plans Disclosure) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,158	$ 3,106	$ 9,465	$ 9,330
Interest cost	1,662	1,341	4,979	4,028
Expected return on plan assets	(1,788)	(1,884)	(5,364)	(5,651)
Amortization of prior service cost	61	82	182	247
Amortization of prior actuarial loss	1,073	929	3,215	2,792
Total	4,166	3,574	12,477	10,746
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	461	999	1,975	2,271
Interest cost	827	680	1,986	1,739
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	(328)	(328)	(986)	(986)
Amortization of prior actuarial loss	29	937	1,317	1,933
Total	$ 989	$ 2,288	$ 4,292	$ 4,957

Reinsurance (Ceded Reinsurance

Reinsurance (Ceded Reinsurance Receivable Assets) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Ceded Credit Risk [Line Items]
Reinsurance ceded receivables	$ 863,027	$ 757,572
Reinsurance Recoverables, Percentage of Total	100.00%	100.00%
Other Reinsurers [Member]
Ceded Credit Risk [Line Items]
Reinsurance ceded receivables	$ 128,301	$ 114,723
Reinsurance Recoverables, Percentage of Total	14.90%	15.20%
AM Best, A+ Rating [Member] | Reinsurer A [Member]
Ceded Credit Risk [Line Items]
Reinsurance ceded receivables	$ 358,845	$ 303,036
Reinsurance Recoverables, Percentage of Total	41.60%	40.00%
AM Best, A+ Rating [Member] | Reinsurer B [Member]
Ceded Credit Risk [Line Items]
Reinsurance ceded receivables	$ 201,011	$ 193,324
Reinsurance Recoverables, Percentage of Total	23.30%	25.50%
AM Best, A+ Rating [Member] | Reinsurer E [Member]
Ceded Credit Risk [Line Items]
Reinsurance ceded receivables	$ 40,816	$ 40,004
Reinsurance Recoverables, Percentage of Total	4.70%	5.30%
AM Best, A Rating [Member] | Reinsurer C [Member]
Ceded Credit Risk [Line Items]
Reinsurance ceded receivables	$ 76,807	$ 69,885
Reinsurance Recoverables, Percentage of Total	8.90%	9.20%
AM Best, A++ Rating [Member] | Reinsurer D [Member]
Ceded Credit Risk [Line Items]
Reinsurance ceded receivables	$ 57,247	$ 36,600
Reinsurance Recoverables, Percentage of Total	6.60%	4.80%

Reinsurance (Narrative) (Detail

Reinsurance (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Ceded Credit Risk [Line Items]
Reinsurance Claims Recoverables	$ 189.9	$ 242.8
Claims Recoverable From Retrocessionaires Past Due	$ 15.6	$ 17.4
AM Best, A- Rating [Member]
Ceded Credit Risk [Line Items]
Ceded Credit Risk, Disclosure	“A- (excellent)”	“A- (excellent)”

Policy Claims and Benefits (Det

Policy Claims and Benefits (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Liability for Claims and Claims Adjustment Expense	$ 6,584,668	$ 5,896,469
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	(432,582)	(455,547)
Liability For Unpaid Claims And Claims Adjustment Expense Net Of Recoverable	6,152,086	5,440,922
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims [Abstract]
Current Year Claims and Claims Adjustment Expense	8,203,842	7,534,297
Prior Year Claims and Claims Adjustment Expense	108,023	97,336
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims	8,311,865	7,631,633
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid [Abstract]
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Current Year	(2,937,099)	(2,748,547)
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid, Prior Years	(4,774,623)	(4,222,550)
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid	(7,711,722)	(6,971,097)
Liability for Unpaid Claims and Claims Adjustment Expense, Interest Accretion	19,887	18,550
Liability for Unpaid Claims and Claims Adjustment Expense, Foreign Currency Translation Gain (Loss)	(99,788)	(153,247)
Liability for Unpaid Claims and Claims Adjustment Expense, Adjustments	(79,901)	(134,697)
Liability For Unpaid Claims And Claims Adjustment Expense Net Of Recoverable	6,672,328	5,966,761
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments	508,003	424,545
Liability for Claims and Claims Adjustment Expense	$ 7,180,331	$ 6,391,306

Financing Activities (Details)

Financing Activities (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	May 15, 2029
Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Issuance Date	May 15, 2019
Debt Instrument, Interest Rate, Stated Percentage	3.90%
Debt Instrument, Face Amount	$ 600
Long-term Debt, Gross	593.8
Debt Issuance Costs, Net	$ 4.8
Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.45%
Debt Instrument, Face Amount	$ 400

New Accounting Standards New Ac

New Accounting Standards New Accounting Standards (Narrative) (Details) $ in Millions	Sep. 30, 2019USD ($)
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	$ 55.2