Summary of Investments (Tables)

6 Months Ended

Jun. 30, 2013

Summary of fixed maturity investments classified as available-for-sale and the non-credit related components of OTTI in AOCI

	June 30, 2013
	Amortized		Gross unrealized		Gross unrealized		Estimated fair value		OTTI (gain) loss
Fixed maturities:	cost		gains		losses		and carrying value		included in AOCI (1)
U.S. government direct obligations and U.S. agencies	$	923,046	$	56,313	$	6,875	$	972,484	$	—
Obligations of U.S. states and their subdivisions	1,731,629		235,248		7,784		1,959,093		—
Foreign government securities	2,698		—		25		2,673		—
Corporate debt securities (2)	10,164,568		618,701		240,214		10,543,055		(2,455		)
Asset-backed securities	1,743,165		120,098		32,660		1,830,603		(78,652		)
Residential mortgage-backed securities	338,222		11,948		2,490		347,680		(214		)
Commercial mortgage-backed securities	593,273		26,092		5,976		613,389		—
Collateralized debt obligations	13,166		14		598		12,582		—
Total fixed maturities	$	15,509,767	$	1,068,414	$	296,622	$	16,281,559	$	(81,321	)

(1) Indicates the amount of any OTTI (gain) loss included in AOCI that is included in gross unrealized gains and losses. OTTI (gain) loss included in AOCI, as presented above, includes both the initial recognition of non-credit losses and the effects of subsequent increases and decreases in estimated fair value for those fixed maturity securities with previous non-credit impairment. The non-credit loss component of OTTI (gain) loss was in an unrealized gain position due to increases in estimated fair value subsequent to initial recognition of non-credit losses on such securities.

(2) Includes perpetual debt investments with amortized cost of $172,054 and estimated fair value of $135,573.

	December 31, 2012
	Amortized		Gross unrealized		Gross unrealized		Estimated fair value		OTTI (gain) loss
Fixed maturities:	cost		gains		losses		and carrying value		included in AOCI (1)
U.S. government direct obligations and U.S. agencies	$	2,735,917	$	101,568	$	3,411	$	2,834,074	$	—
Obligations of U.S. states and their subdivisions	1,676,289		342,445		229		2,018,505		—
Corporate debt securities (2)	9,511,411		974,231		111,551		10,374,091		(2,293		)
Asset-backed securities	1,795,122		120,471		54,454		1,861,139		(66,293		)
Residential mortgage-backed securities	407,715		17,900		30		425,585		(240		)
Commercial mortgage-backed securities	616,011		48,247		1,303		662,955		—
Collateralized debt obligations	13,751		14		1,770		11,995		—
Total fixed maturities	$	16,756,216	$	1,604,876	$	172,748	$	18,188,344	$	(68,826	)

(2) Includes perpetual debt investments with amortized cost of $226,069 and estimated fair value of $153,100.

Schedule of amortized cost and estimated fair value of fixed maturity investments classified as available-for-sale

	June 30, 2013
	Amortized cost		Estimated fair value
Maturing in one year or less	$	815,999	$	849,614
Maturing after one year through five years	3,071,738		3,321,878
Maturing after five years through ten years	3,626,928		3,889,260
Maturing after ten years	4,607,710		4,669,382
Mortgage-backed and asset-backed securities	3,387,392		3,551,425
	$	15,509,767	$	16,281,559

Summary of information regarding the sales of securities classified as available-for-sale

	Three months ended June 30,				Six months ended June 30,
	2013		2012		2013		2012
Proceeds from sales	$	2,059,748	$	964,142	$	5,360,913	$	2,390,054
Gross realized gains from sales	18,191		23,499		51,404		43,505
Gross realized losses from sales	19,636		1,420		26,912		2,901

Schedule of the carrying value of the mortgage loan portfolio by component

	June 30, 2013			December 31, 2012
Principal	$	3,044,912		$	2,866,411
Unamortized premium (discount)	15,884			18,237
Mortgage provision allowance	(2,890		)	(2,890		)
Total mortgage loans	$	3,057,906		$	2,881,758

Schedule of activity in the mortgage provision allowance

	Six months ended June 30, 2013			Year ended December 31, 2012
	Commercial mortgages			Commercial mortgages
Beginning balance	$	2,890		$	21,130
Provision increases	273			1,067
Charge-off	(273		)	(992		)
Recovery	—			(75		)
Provision decreases	—			(18,240		)
Ending balance	$	2,890		$	2,890

Allowance ending balance by basis of impairment method:
Collectively evaluated for impairment	$	2,890		$	2,890

Recorded investment balance in the mortgage loan portfolio, gross of allowance, by basis of impairment method:	$	3,060,796		$	2,884,648
Individually evaluated for impairment	21,167			14,970
Collectively evaluated for impairment	3,039,629			2,869,678

Schedule of unrealized investment losses, including the non-credit-related portion of OTTI losses reported in AOCI, by class of investment

	June 30, 2013
	Less than twelve months				Twelve months or longer				Total
	Estimated		Unrealized		Estimated		Unrealized		Estimated		Unrealized
Fixed maturities:	fair value		loss and OTTI		fair value		loss and OTTI		fair value		loss and OTTI
U.S. government direct obligations and U.S. agencies	$	206,332	$	6,720	$	4,532	$	155	$	210,864	$	6,875
Obligations of U.S. states and their subdivisions	135,157		7,784		—		—		135,157		7,784
Foreign government securities	2,673		25		—		—		2,673		25
Corporate debt securities	2,651,521		173,565		228,995		66,649		2,880,516		240,214
Asset-backed securities	273,746		10,285		354,453		22,375		628,199		32,660
Residential mortgage-backed securities	36,313		2,471		1,104		19		37,417		2,490
Commercial mortgage-backed securities	77,276		5,976		—		—		77,276		5,976
Collateralized debt obligations	—		—		12,550		598		12,550		598
Total fixed maturities	$	3,383,018	$	206,826	$	601,634	$	89,796	$	3,984,652	$	296,622

Total number of securities in an unrealized loss position			354				92				446

	December 31, 2012
	Less than twelve months				Twelve months or longer				Total
	Estimated		Unrealized		Estimated		Unrealized		Estimated		Unrealized
Fixed maturities:	fair value		loss and OTTI		fair value		loss and OTTI		fair value		loss and OTTI
U.S. government direct obligations and U.S. agencies	$	538,612	$	3,270	$	7,252	$	141	$	545,864	$	3,411
Obligations of U.S. states and their subdivisions	25,679		229		—		—		25,679		229
Corporate debt securities	527,280		12,287		291,611		99,264		818,891		111,551
Asset-backed securities	30,810		97		647,715		54,357		678,525		54,454
Residential mortgage-backed securities	9,834		8		1,210		22		11,044		30
Commercial mortgage-backed securities	34,727		169		35,960		1,134		70,687		1,303
Collateralized debt obligations	—		—		11,963		1,770		11,963		1,770
Total fixed maturities	$	1,166,942	$	16,060	$	995,711	$	156,688	$	2,162,653	$	172,748

Total number of securities in an unrealized loss position			85				133				218

Schedule of recorded OTTI on fixed maturity investments

	Three months ended June 30,				Six months ended June 30,
	2013		2012		2013		2012
Beginning balance	$	167,961	$	186,999	$	167,788	$	186,999
Additional credit loss recognized on securities previously impaired	—		—		173		—
Ending balance	$	167,961	$	186,999	$	167,961	$	186,999

- Definition

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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- Definition

Tabular disclosure of the amount of other than temporary impairment (OTTI) related to credit losses recognized in earnings including: (a) the beginning balance of the amount related to credit losses on debt securities held by the investor at the beginning of the period for which a portion of an OTTI was recognized in other comprehensive income; (b) additions for the amount related to the credit loss for which an OTTI was not previously recognized; (c) reductions for securities sold during the period (realized); (d) reductions for securities for which the amount previously recognized in other comprehensive income was recognized in earnings because the investor intends to sell the security or more likely than not will be required to sell the security before recovery of its amortized cost basis; (e) additional increases to the amount related to the credit loss for which an OTTI was previously recognized when the investor does not intend to sell the security and it is not more likely than not that the investor will be required to sell the security before recovery of its amortized cost basis; (f) reductions for increases in cash flows expected to be collected that are recognized over the remaining life of the security; and (g) the ending balance of the amount related to credit losses on debt securities held by the entity at the end of the period for which a portion of an OTTI was recognized in other comprehensive income.

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