Investment Securities (Tables)

12 Months Ended

Dec. 31, 2010

Investment Securities [Abstract]

Amortized Cost And Fair Value Of Available For Sale Debt Securities

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
December 31, 2010
U.S. Treasury and other U.S. government corporations and agencies:
U.S. Treasury and agency obligations	$	697,816	$	14,412	$	(615	)	$	711,613
Mortgage-backed securities		1,614,569		49,783		(1,173	)		1,663,179
Tax-exempt municipal securities		2,439,659		37,294		(43,619	)		2,433,334
Mortgage-backed securities:
Residential		58,017		545		(2,675	)		55,887
Commercial		306,291		14,911		(171	)		321,031
Asset-backed securities		148,068		1,727		(44	)		149,751
Corporate debt securities		2,906,228		139,793		(13,710	)		3,032,311
Redeemable preferred stock		5,333		0		0			5,333
Total debt securities	$	8,175,981	$	258,465	$	(62,007	)	$	8,372,439
December 31, 2009
U.S. Treasury and other U.S. government corporations and agencies:
U.S. Treasury and agency obligations	$	1,005,203	$	6,683	$	(2,534	)	$	1,009,352
Mortgage-backed securities		1,675,667		24,324		(11,328	)		1,688,663
Tax-exempt municipal securities		2,195,077		52,381		(23,417	)		2,224,041
Mortgage-backed securities:
Residential		106,191		220		(10,999	)		95,412
Commercial		285,014		3,252		(8,640	)		279,626
Asset-backed securities		106,471		824		(107	)		107,188
Corporate debt securities		2,043,721		57,173		(21,326	)		2,079,568
Redeemable preferred stock		8,400		4,900		0			13,300
Total debt securities	$	7,425,744	$	149,757	$	(78,351	)	$	7,497,150

Unrealized Loss Position Investments

	Less than 12 months					12 months or more					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
	(in thousands)
December 31, 2010
U.S. Treasury and other U.S. government corporations and agencies:
U.S. Treasury and agency obligations	$	141,766	$	(615	)	$	0	$	0		$	141,766	$	(615	)
Mortgage-backed securities		110,358		(1,054	)		5,557		(119	)		115,915		(1,173	)
Tax-exempt municipal securities		1,168,221		(33,218	)		97,809		(10,401	)		1,266,030		(43,619	)
Mortgage-backed securities:
Residential		0		0			32,671		(2,675	)		32,671		(2,675	)
Commercial		0		0			2,752		(171	)		2,752		(171	)
Asset-backed securities		17,069		(42	)		283		(2	)		17,352		(44	)
Corporate debt securities		383,677		(9,572	)		31,464		(4,138	)		415,141		(13,710	)
Total debt securities	$	1,821,091	$	(44,501	)	$	170,536	$	(17,506	)	$	1,991,627	$	(62,007	)
December 31, 2009
U.S. Treasury and other U.S. government corporations and agencies:
U.S. Treasury and agency obligations	$	301,843	$	(2,425	)	$	2,970	$	(109	)	$	304,813	$	(2,534	)
Mortgage-backed securities		823,365		(11,005	)		6,834		(323	)		830,199		(11,328	)
Tax-exempt municipal securities		598,520		(14,286	)		198,327		(9,131	)		796,847		(23,417	)
Mortgage-backed securities:
Residential		1,771		(5	)		73,178		(10,994	)		74,949		(10,999	)
Commercial		31,941		(359	)		142,944		(8,281	)		174,885		(8,640	)
Asset-backed securities		1,930		(19	)		2,179		(88	)		4,109		(107	)
Corporate debt securities		636,833		(9,354	)		99,830		(11,972	)		736,663		(21,326	)
Total debt securities	$	2,396,203	$	(37,453	)	$	526,262	$	(40,898	)	$	2,922,465	$	(78,351	)

Realized Investment Gains (Losses), Net

	2010			2009			2008
	(in thousands)
Gross realized gains	$	34,815		$	123,361		$	56,879
Gross realized losses		(29,169	)		(103,878	)		(136,296	)
Net realized capital gains (losses)	$	5,646		$	19,483		$	(79,417	)

Investments Classified By Contractual Maturity Date

	Amortized Cost		Fair Value
	(in thousands)
Due within one year	$	299,861	$	301,630
Due after one year through five years		1,936,215		1,991,966
Due after five years through ten years		2,072,510		2,134,576
Due after ten years		1,740,450		1,754,419
Mortgage and asset-backed securities		2,126,945		2,189,848
Total debt securities	$	8,175,981	$	8,372,439