Investments (Tables)

3 Months Ended

Mar. 31, 2017

The following tables provide information relating to investments in fixed maturity and equity securities by sector as of March 31, 2017 and December 31, 2016 (dollars in thousands):



March 31, 2017:	Amortized		Unrealized		Unrealized		Estimated Fair		% of		Other-than- temporary impairments
	Cost		Gains		Losses		Value		Total		in AOCI
Available-for-sale:
Corporate securities	$	19,281,539	$	1,037,337	$	157,423	$	20,161,453	61.8	%	$	—
Canadian and Canadian provincial governments	2,601,403		1,122,418		3,457		3,720,364		11.4		—
Residential mortgage-backed securities	1,281,171		34,382		11,676		1,303,877		4.0		—
Asset-backed securities	1,379,251		14,480		13,141		1,380,590		4.2		275
Commercial mortgage-backed securities	1,272,020		24,353		7,035		1,289,338		3.9		—
U.S. government and agencies	1,522,651		15,135		55,334		1,482,452		4.5		—
State and political subdivisions	566,553		40,471		11,567		595,457		1.8		—
Other foreign government, supranational and foreign government-sponsored enterprises	2,635,979		136,850		11,567		2,761,262		8.4		—
Total fixed maturity securities	$	30,540,567	$	2,425,426	$	271,200	$	32,694,793	100.0	%	$	275
Non-redeemable preferred stock	$	33,656	$	360	$	2,801	$	31,215	28.0	%
Other equity securities	83,473		532		3,604		80,401		72.0
Total equity securities	$	117,129	$	892	$	6,405	$	111,616	100.0	%



December 31, 2016:	Amortized		Unrealized		Unrealized		Estimated Fair		% of		Other-than- temporary impairments
	Cost		Gains		Losses		Value		Total		in AOCI
Available-for-sale:
Corporate securities	$	18,924,711	$	911,618	$	217,245	$	19,619,084	61.1	%	$	—
Canadian and Canadian provincial governments	2,561,605		1,085,982		3,541		3,644,046		11.4		—
Residential mortgage-backed securities	1,258,039		33,917		13,380		1,278,576		4.0		(375		)
Asset-backed securities	1,443,822		9,350		23,828		1,429,344		4.5		275
Commercial mortgage-backed securities	1,342,440		28,973		7,759		1,363,654		4.2		—
U.S. government and agencies	1,518,702		12,644		63,044		1,468,302		4.6		—
State and political subdivisions	566,761		37,499		12,464		591,796		1.8		—
Other foreign government, supranational and foreign government-sponsored enterprises	2,595,707		123,054		19,938		2,698,823		8.4		—
Total fixed maturity securities	$	30,211,787	$	2,243,037	$	361,199	$	32,093,625	100.0	%	$	(100	)
Non-redeemable preferred stock	$	55,812	$	1,648	$	6,337	$	51,123	18.6	%
Other equity securities	229,767		1,792		7,321		224,238		81.4
Total equity securities	$	285,579	$	3,440	$	13,658	$	275,361	100.0	%

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 March 31, 2017 and December 31, 2016 (dollars in thousands):



	March 31, 2017				December 31, 2016
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Fixed maturity securities pledged as collateral	$	183,860	$	189,387	$	207,066	$	210,676
Fixed maturity securities received as collateral	n/a		414,893		n/a		300,925
Assets in trust held to satisfy collateral requirements	12,157,811		13,015,274		12,135,258		12,874,370

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 March 31, 2017 and December 31, 2016 (dollars in thousands).



	March 31, 2017				December 31, 2016
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Fixed maturity securities guaranteed or issued by:
Canadian province of Quebec	$	1,020,682	$	1,644,422	$	1,004,261	$	1,612,957
Canadian province of Ontario	852,739		1,157,169		832,764		1,126,433

Investments Classified By Contractual Maturity Date

The amortized cost and estimated fair value of fixed maturity securities classified as available-for-sale at March 31, 2017 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	$	837,801	$	849,530
Due after one year through five years	6,853,278		7,132,145
Due after five years through ten years	9,113,078		9,548,835
Due after ten years	9,803,968		11,190,478
Asset and mortgage-backed securities	3,932,442		3,973,805
Total	$	30,540,567	$	32,694,793

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 March 31, 2017 and December 31, 2016 (dollars in thousands):



March 31, 2017:			Estimated
	Amortized Cost		Fair Value		% of Total
Finance	$	6,862,721	$	7,103,865	35.2	%
Industrial	10,398,548		10,889,185		54.0
Utility	2,020,270		2,168,403		10.8
Total	$	19,281,539	$	20,161,453	100.0	%

December 31, 2016:			Estimated
	Amortized Cost		Fair Value		% of Total
Finance	$	6,725,199	$	6,888,968	35.2	%
Industrial	10,228,813		10,639,613		54.2
Utility	1,970,699		2,090,503		10.6
Total	$	18,924,711	$	19,619,084	100.0	%

Roll Forward Of Cumulative Credit Loss Component Of Otti Income Loss [Table Text Block]

The following table sets forth the amount of pre-tax credit loss impairments on fixed maturity securities held by the Company as of the dates indicated, for which a portion of the OTTI loss was recognized in AOCI, and the corresponding changes in such amounts (dollars in thousands):



	Three months ended March 31,
	2017			2016
Balance, beginning of period	$	6,013		$	7,284
Credit loss OTTI previously recognized on securities impaired to fair value during the period	(2,336		)	—
Balance, end of period	$	3,677		$	7,284

Investments In Debt And Equity Securities Gross Unrealized Losses Disclosures

The following table presents the total gross unrealized losses for the 1,308 and 1,535 fixed maturity and equity securities as of March 31, 2017 and December 31, 2016, respectively, where the estimated fair value had declined and remained below amortized cost by the indicated amount (dollars in thousands):



	March 31, 2017				December 31, 2016
	Gross Unrealized Losses		% of Total		Gross Unrealized Losses		% of Total
Less than 20%	$	251,640	90.7	%	$	337,831	90.1	%
20% or more for less than six months	4,113		1.5		19,438		5.2
20% or more for six months or greater	21,852		7.8		17,588		4.7
Total	$	277,605	100.0	%	$	374,857	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 1,308 and 1,535 fixed maturity and equity securities that have estimated fair values below amortized cost as of March 31, 2017 and December 31, 2016, 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
March 31, 2017:	Estimated		Unrealized		Estimated		Unrealized		Estimated		Unrealized
	Fair Value		Losses		Fair Value		Losses		Fair Value		Losses
Investment grade securities:
Corporate securities	$	3,658,776	$	89,271	$	412,413	$	33,285	$	4,071,189	$	122,556
Canadian and Canadian provincial governments	137,014		3,457		—		—		137,014		3,457
Residential mortgage-backed securities	467,812		9,394		101,886		2,277		569,698		11,671
Asset-backed securities	381,219		4,213		270,456		8,248		651,675		12,461
Commercial mortgage-backed securities	370,152		6,816		7,398		111		377,550		6,927
U.S. government and agencies	1,122,884		55,334		—		—		1,122,884		55,334
State and political subdivisions	155,720		7,963		13,086		3,604		168,806		11,567
Other foreign government, supranational and foreign government-sponsored enterprises	432,726		9,041		40,431		1,985		473,157		11,026
Total investment grade securities	6,726,303		185,489		845,670		49,510		7,571,973		234,999
Below investment grade securities:
Corporate securities	195,427		3,023		110,909		31,844		306,336		34,867
Residential mortgage-backed securities	—		—		122		5		122		5
Asset-backed securities	—		—		11,463		680		11,463		680
Commercial mortgage-backed securities	1,891		108		—		—		1,891		108
Other foreign government, supranational and foreign government-sponsored enterprises	9,704		84		14,163		457		23,867		541
Total below investment grade securities	207,022		3,215		136,657		32,986		343,679		36,201
Total fixed maturity securities	$	6,933,325	$	188,704	$	982,327	$	82,496	$	7,915,652	$	271,200
Non-redeemable preferred stock	$	—	$	—	$	24,289	$	2,801	$	24,289	$	2,801
Other equity securities	70,591		3,604		—		—		70,591		3,604
Total equity securities	$	70,591	$	3,604	$	24,289	$	2,801	$	94,880	$	6,405



	Less than 12 months				12 months or greater				Total
			Gross				Gross				Gross
December 31, 2016:	Estimated		Unrealized		Estimated		Unrealized		Estimated		Unrealized
	Fair Value		Losses		Fair Value		Losses		Fair Value		Losses
Investment grade securities:
Corporate securities	$	4,661,706	$	124,444	$	549,273	$	43,282	$	5,210,979	$	167,726
Canadian and Canadian provincial governments	101,578		3,541		—		—		101,578		3,541
Residential mortgage-backed securities	490,473		9,733		112,216		3,635		602,689		13,368
Asset-backed securities	563,259		12,010		257,166		9,653		820,425		21,663
Commercial mortgage-backed securities	368,465		6,858		10,853		166		379,318		7,024
U.S. government and agencies	1,056,101		63,044		—		—		1,056,101		63,044
State and political subdivisions	187,194		9,396		13,635		3,068		200,829		12,464
Other foreign government, supranational and foreign government-sponsored enterprises	524,236		13,372		51,097		2,981		575,333		16,353
Total investment grade securities	7,953,012		242,398		994,240		62,785		8,947,252		305,183
Below investment grade securities:
Corporate securities	330,757		7,914		163,152		41,605		493,909		49,519
Residential mortgage-backed securities	—		—		412		12		412		12
Asset-backed securities	5,904		700		12,581		1,465		18,485		2,165
Commercial mortgage-backed securities	5,815		735		—		—		5,815		735
Other foreign government, supranational and foreign government-sponsored enterprises	32,355		1,258		39,763		2,327		72,118		3,585
Total below investment grade securities	374,831		10,607		215,908		45,409		590,739		56,016
Total fixed maturity securities	$	8,327,843	$	253,005	$	1,210,148	$	108,194	$	9,537,991	$	361,199
Non-redeemable preferred stock	$	10,831	$	831	$	21,879	$	5,506	$	32,710	$	6,337
Other equity securities	202,068		7,020		6,751		301		208,819		7,321
Total equity securities	$	212,899	$	7,851	$	28,630	$	5,807	$	241,529	$	13,658

Investment Income

Major categories of investment income, net of related expenses, consist of the following (dollars in thousands):



	Three months ended March 31,
	2017			2016
Fixed maturity securities available-for-sale	$	324,500		$	312,414
Mortgage loans on real estate	44,347			39,792
Policy loans	15,272			16,134
Funds withheld at interest	127,578			55,980
Short-term investments and cash and cash equivalents	1,510			2,191
Other	19,827			8,608
Investment income	533,034			435,119
Investment expense	(18,670		)	(17,853		)
Investment income, net of related expenses	$	514,364		$	417,266

Gain Loss On Investments

Investment related gains (losses), net consist of the following (dollars in thousands):



	Three months ended March 31,
	2017			2016
Fixed maturity and equity securities available for sale:
Other-than-temporary impairment losses on fixed maturity securities recognized in earnings	$	(17,189	)	$	(33,817	)
Gain on investment activity	17,893			27,192
Loss on investment activity	(12,563		)	(11,787		)
Other impairment losses and change in mortgage loan provision	(99		)	(2,060		)
Derivatives and other, net	72,481			(100,414		)
Total investment related gains (losses), net	$	60,523		$	(120,886	)

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 March 31, 2017 and December 31, 2016 (dollars in thousands).



	March 31, 2017				December 31, 2016
	Amortized Cost		Estimated Fair Value		Amortized Cost		Estimated Fair Value
Borrowed securities	$	265,180	$	279,637	$	263,820	$	279,186
Securities lending:
Securities loaned	87,865		88,486		74,389		73,625
Securities received	n/a		94,000		n/a		80,000
Repurchase program/reverse repurchase program:
Securities pledged	480,965		504,645		476,531		499,891
Securities received	n/a		518,358		n/a		515,200

Schedule of Underlying Assets of Repurchase Agreements when Amount of Repurchase Agreements Exceeds 10 Percent of Assets [Table Text Block]

The following table presents information on the Company’s securities lending and repurchase transactions as of March 31, 2017 and December 31, 2016 (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.



	March 31, 2017
	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 securities	$	—	$	—	$	—	$	88,486	$	88,486
Total	$	—	$	—	$	—	$	88,486	$	88,486
Repurchase transactions:
Corporate securities	$	—	$	—	$	2,531	$	172,119	$	174,650
Residential mortgage-backed securities	—		—		—		90,422		90,422
U.S. government and agencies	—		—		30,006		185,811		215,817
Foreign government	—		—		—		20,411		20,411
Other	3,345		—		—		—		3,345
Total	3,345		—		32,537		468,763		504,645
Total borrowings	$	3,345	$	—	$	32,537	$	557,249	$	593,131

Gross amount of recognized liabilities for securities lending and repurchase transactions in preceding table									$	642,874
Amounts related to agreements not included in offsetting disclosure									$	49,743



	December 31, 2016
	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 securities	$	—	$	—	$	4,017	$	69,608	$	73,625
Total	$	—	$	—	$	4,017	$	69,608	$	73,625
Repurchase transactions:
Corporate securities	$	—	$	—	$	3,220	$	166,979	$	170,199
Residential mortgage-backed securities	—		—		—		92,546		92,546
U.S. government and agencies	—		—		—		216,000		216,000
Foreign government	—		—		—		19,900		19,900
Other	1,246		—		—		—		1,246
Total	1,246		—		3,220		495,425		499,891
Total borrowings	$	1,246	$	—	$	7,237	$	565,033	$	573,516

Gross amount of recognized liabilities for securities lending and repurchase transactions in preceding table									$	624,032
Amounts related to agreements not included in offsetting disclosure									$	50,516

Disclosure Of Real Estate Holdings By Property Type [Table Text Block]

he distribution of mortgage loans by property type is as follows as of March 31, 2017 and December 31, 2016 (dollars in thousands):



	March 31, 2017					December 31, 2016
Property type:	Carrying Value			% of Total		Carrying Value			% of Total
Office building	$	1,329,399		34.2	%	$	1,270,113		33.6	%
Retail	1,202,317			31.0		1,179,936			31.2
Industrial	750,978			19.4		713,461			18.8
Apartment	425,614			11.0		447,088			11.8
Other commercial	171,461			4.4		172,609			4.6
Recorded investment	3,879,769			100.0	%	$	3,783,207		100.0	%
Unamortized balance of loan origination fees and expenses	(674		)			—
Valuation allowances	(7,786		)			(7,685		)
Total mortgage loans on real estate	$	3,871,309				$	3,775,522

Mortgage Loans Classified By Contractual Maturity Date [Table Text Block]

he maturities of the mortgage loans as of March 31, 2017 and December 31, 2016 are as follows (dollars in thousands):



	March 31, 2017				December 31, 2016
	Recorded Investment		% of Total		Recorded Investment		% of Total
Due within five years	$	907,453	23.4	%	$	822,073	21.7	%
Due after five years through ten years	2,144,303		55.3		2,099,559		55.5
Due after ten years	828,013		21.3		861,575		22.8
Total	$	3,879,769	100.0	%	$	3,783,207	100.0	%

Mortgage Loan Internal Credit Risk Grade [Table Text Block]

The following tables set forth certain key credit quality indicators of the Company’s recorded investment in mortgage loans as of March 31, 2017 and December 31, 2016 (dollars in thousands):



	Recorded Investment
	Debt Service Ratios
	>1.20x		1.00x - 1.20x		<1.00x		Total		% of Total
March 31, 2017:
Loan-to-Value Ratio
0% - 59.99%	$	1,967,449	$	64,541	$	1,183	$	2,033,173	52.3	%
60% - 69.99%	1,259,650		34,584		—		1,294,234		33.4
70% - 79.99%	368,504		20,734		24,207		413,445		10.7
Greater than 80%	103,896		—		35,021		138,917		3.6
Total	$	3,699,499	$	119,859	$	60,411	$	3,879,769	100.0	%



	Recorded Investment
	Debt Service Ratios
	>1.20x		1.00x - 1.20x		<1.00x		Total		% of Total
December 31, 2016:
Loan-to-Value Ratio
0% - 59.99%	$	1,859,640	$	64,749	$	1,366	$	1,925,755	50.8	%
60% - 69.99%	1,257,788		34,678		—		1,292,466		34.2
70% - 79.99%	370,092		20,869		24,369		415,330		11.0
Greater than 80%	114,297		—		35,359		149,656		4.0
Total	$	3,601,817	$	120,296	$	61,094	$	3,783,207	100.0	%

Recorded Investment And Allowance For Credit Losses

he following table presents the recorded investment in mortgage loans, by method of measuring impairment, and the related valuation allowances as of March 31, 2017 and December 31, 2016 (dollars in thousands):



	March 31, 2017		December 31, 2016
Mortgage loans:
Individually measured for impairment	$	2,099	$	2,216
Collectively measured for impairment	3,877,670		3,780,991
Recorded investment	$	3,879,769	$	3,783,207
Valuation allowances:
Individually measured for impairment	$	—	$	—
Collectively measured for impairment	7,786		7,685
Total valuation allowances	$	7,786	$	7,685

Allowance For Mortgage Loan And Lease Losses Provision For Loss Net

nformation regarding the Company’s loan valuation allowances for mortgage loans for the three months ended March 31, 2017 and 2016 is as follows (dollars in thousands):



	Three months ended March 31,
	2017		2016
Balance, beginning of period	$	7,685	$	6,813
Provision (release)	101		11
Balance, end of period	$	7,786	$	6,824

Impaired Financing Receivables Table

Information regarding the portion of the Company’s mortgage loans that were impaired as of March 31, 2017 and December 31, 2016 is as follows (dollars in thousands):



	Unpaid Principal Balance		Recorded Investment		Related Allowance		Carrying Value
March 31, 2017:
Impaired mortgage loans with no valuation allowance recorded	$	2,641	$	2,099	$	—	$	2,099
Impaired mortgage loans with valuation allowance recorded	—		—		—		—
Total impaired mortgage loans	$	2,641	$	2,099	$	—	$	2,099
December 31, 2016:
Impaired mortgage loans with no valuation allowance recorded	$	2,758	$	2,216	$	—	$	2,216
Impaired mortgage loans with valuation allowance recorded	—		—		—		—
Total impaired mortgage loans	$	2,758	$	2,216	$	—	$	2,216

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 March 31,
	2017				2016
	Average Recorded Investment⁽¹⁾		Interest Income		Average Recorded Investment⁽¹⁾		Interest Income
Impaired mortgage loans with no valuation allowance recorded	$	2,157	$	33	$	2,421	$	12
Impaired mortgage loans with valuation allowance recorded	—		—		10,918		144
Total impaired mortgage loans	$	2,157	$	33	$	13,339	$	156

(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]

arrying values of these assets as of March 31, 2017 and December 31, 2016 are as follows (dollars in thousands):



	March 31, 2017		December 31, 2016
Equity securities	$	111,616	$	275,361
Limited partnership interests and real estate joint ventures	706,143		687,522
Derivatives	170,183		229,108
FVO contractholder-directed unit-linked investments	193,600		190,120
Other	247,633		209,829
Total other invested assets	$	1,429,175	$	1,591,940