Investments (Tables)

3 Months Ended

Mar. 31, 2012

Investments [Abstract]

Available-For-Sale Investments

The following tables summarize the Company’s available-for-sale investments.

	March 31, 2012
(dollars in thousands)	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Unrealized Other-Than- Temporary Impairment Losses			Estimated Fair Value
Fixed maturities:
U.S. Treasury securities and obligations of U.S. government agencies	$	325,998	$	20,302	$	(222	)	$	—		$	346,078
Obligations of states, municipalities and political subdivisions	2,709,251		208,549		(924		)	—			2,916,876
Foreign governments	576,187		44,863		(331		)	—			620,719
Residential mortgage-backed securities	331,526		23,990		(5		)	(2,258		)	353,253
Asset-backed securities	15,779		688		—			—			16,467
Public utilities	65,294		5,536		—			—			70,830
All other corporate bonds	1,101,738		88,804		(303		)	(6,798		)	1,183,441
Total fixed maturities	5,125,773		392,732		(1,785		)	(9,056		)	5,507,664
Equity securities:
Insurance companies, banks and trusts	417,044		351,298		—			—			768,342
Industrial, consumer and all other	835,170		563,930		(601		)	—			1,398,499
Total equity securities	1,252,214		915,228		(601		)	—			2,166,841
Short-term investments	463,697		4		(7		)	—			463,694
Investments, available-for-sale	$	6,841,684	$	1,307,964	$	(2,393	)	$	(9,056	)	$	8,138,199

	December 31, 2011
(dollars in thousands)	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Unrealized Other-Than- Temporary Impairment Losses			Estimated Fair Value
Fixed maturities:
U.S. Treasury securities and obligations of U.S. government agencies	$	299,413	$	22,789	$	(9	)	$	—		$	322,193
Obligations of states, municipalities and political subdivisions	2,729,838		201,477		(794		)	—			2,930,521
Foreign governments	572,253		45,629		(1,068		)	—			616,814
Residential mortgage-backed securities	366,859		24,601		(18		)	(2,258		)	389,184
Asset-backed securities	16,096		731		(9		)	—			16,818
Public utilities	63,965		5,462		—			—			69,427
All other corporate bonds	1,124,528		78,053		(2,750		)	(6,614		)	1,193,217
Total fixed maturities	5,172,952		378,742		(4,648		)	(8,872		)	5,538,174
Equity securities:
Insurance companies, banks and trusts	389,421		296,648		(1,366		)	—			684,703
Industrial, consumer and all other	766,873		425,131		(2,780		)	—			1,189,224
Total equity securities	1,156,294		721,779		(4,146		)	—			1,873,927
Short-term investments	541,014		4		(4		)	—			541,014
Investments, available-for-sale	$	6,870,260	$	1,100,525	$	(8,798	)	$	(8,872	)	$	7,953,115

Summary Of Gross Unrealized Investment Losses By Length Of Time That Securities Have Continuously Been In An Unrealized Loss Position

The following tables summarize gross unrealized investment losses by the length of time that securities have continuously been in an unrealized loss position.

	March 31, 2012
	Less than 12 months					12 months or longer					Total
(dollars in thousands)	Estimated Fair Value		Gross Unrealized Holding and Other-Than- Temporary Impairment Losses			Estimated Fair Value		Gross Unrealized Holding and Other-Than- Temporary Impairment Losses			Estimated Fair Value		Gross Unrealized Holding and Other-Than- Temporary Impairment Losses
Fixed maturities:
U.S. Treasury securities and obligations of U.S. government agencies	$	78,023	$	(222	)	$	—	$	—		$	78,023	$	(222	)
Obligations of states, municipalities and political subdivisions	12,592		(240		)	16,189		(684		)	28,781		(924		)
Foreign governments	35,520		(331		)	—		—			35,520		(331		)
Residential mortgage-backed securities	551		(2,263		)	—		—			551		(2,263		)
Asset-backed securities	—		—			—		—			—		—
All other corporate bonds	15,137		(6,954		)	5,908		(147		)	21,045		(7,101		)
Total fixed maturities	141,823		(10,010		)	22,097		(831		)	163,920		(10,841		)
Equity securities:
Insurance companies, banks and trusts	—		—			—		—			—		—
Industrial, consumer and all other	32,272		(590		)	99		(11		)	32,371		(601		)
Total equity securities	32,272		(590		)	99		(11		)	32,371		(601		)
Short-term investments	46,995		(7		)	—		—			46,995		(7		)
Total	$	221,090	$	(10,607	)	$	22,196	$	(842	)	$	243,286	$	(11,449	)

	December 31, 2011
	Less than 12 months					12 months or longer					Total
(dollars in thousands)	Estimated Fair Value		Gross Unrealized Holding and Other-Than- Temporary Impairment Losses			Estimated Fair Value		Gross Unrealized Holding and Other-Than- Temporary Impairment Losses			Estimated Fair Value		Gross Unrealized Holding and Other-Than- Temporary Impairment Losses
Fixed maturities:
U.S. Treasury securities and obligations of U.S. government agencies	$	32,384	$	(9	)	$	—	$	—		$	32,384	$	(9	)
Obligations of states, municipalities and political subdivisions	1,016		(2		)	17,261		(792		)	18,277		(794		)
Foreign governments	40,340		(1,068		)	—		—			40,340		(1,068		)
Residential mortgage-backed securities	489		(2,263		)	2,045		(13		)	2,534		(2,276		)
Asset-backed securities	—		—			32		(9		)	32		(9		)
All other corporate bonds	74,812		(7,829		)	7,923		(1,535		)	82,735		(9,364		)
Total fixed maturities	149,041		(11,171		)	27,261		(2,349		)	176,302		(13,520		)
Equity securities:
Insurance companies, banks and trusts	26,514		(1,366		)	—		—			26,514		(1,366		)
Industrial, consumer and all other	70,555		(2,774		)	18,525		(6		)	89,080		(2,780		)
Total equity securities	97,069		(4,140		)	18,525		(6		)	115,594		(4,146		)
Short-term investments	295,991		(4		)	—		—			295,991		(4		)
Total	$	542,101	$	(15,315	)	$	45,786	$	(2,355	)	$	587,887	$	(17,670	)

Schedule Of Amortized Cost And Estimated Fair Value Of Fixed Maturities By Contractual Maturity Date

The amortized cost and estimated fair value of fixed maturities at March 31, 2012 are shown below by contractual maturity.

(dollars in thousands)	Amortized Cost		Estimated Fair Value
Due in one year or less	$	296,224	$	301,089
Due after one year through five years	1,356,224		1,460,975
Due after five years through ten years	1,601,045		1,730,807
Due after ten years	1,524,975		1,645,073
	4,778,468		5,137,944
Residential mortgage-backed securities	331,526		353,253
Asset-backed securities	15,779		16,467
Total fixed maturities	$	5,125,773	$	5,507,664

Summary Of Net Realized Investment Gains And The Change In Net Unrealized Gains On Investments

The following table presents net realized investment gains and the change in net unrealized gains on investments.

	Three Months Ended March 31,
(dollars in thousands)	2012			2011
Realized gains:
Sales of fixed maturities	$	1,859		$	7,988
Sales of equity securities	9,694			2,071
Other	521			1,425
Total realized gains	12,074			11,484
Realized losses:
Sales of fixed maturities	(165		)	(244		)
Other-than-temporary impairments	—			—
Other	—			—
Total realized losses	(165		)	(244		)
Net realized investment gains	$	11,909		$	11,240
Change in net unrealized gains on investments:
Fixed maturities	$	16,669		$	(16,396	)
Equity securities	196,994			36,857
Short-term investments	(3		)	3
Net increase	$	213,660		$	20,464