Investments

The following table presents (losses) gains due to changes in fair value of investments that are measured at fair value pursuant to application of the fair value option:



	Year Ended December 31,
	2013			2012		2011
	(Amounts in thousands)
Fixed maturity securities	$	(100,703	)	$	36,317	$	62,149
Equity securities	56,822			9,158		(30,879		)
Short-term investments	(156		)	34		19
Total	$	(44,037	)	$	45,509	$	31,289

A summary of net realized investment (losses) gains is as follows:



	Year Ended December 31,
	2013			2012			2011
	(Amounts in thousands)
Net realized (losses) gains from investments and other liabilities:
Fixed maturity securities	$	(95,225	)	$	47,707		$	54,112
Equity securities	80,910			16,679			(4,854		)
Short-term investments	(1,059		)	(686		)	139
Total return swap	2,176			0			0
Options	1,776			2,680			9,000
Total	$	(11,422	)	$	66,380		$	58,397

Gross gains and losses realized on the sales of investments, excluding options, are shown below:



	Year Ended December 31,
	2013								2012								2011
	(Amounts in thousands)
	Gross Realized Gains		Gross Realized Losses			Net			Gross Realized Gains		Gross Realized Losses			Net			Gross Realized Gains		Gross Realized Losses			Net
Fixed maturity securities	$	9,320	$	(3,842	)	$	5,478		$	11,473	$	(83	)	$	11,390		$	2,675	$	(10,712	)	$	(8,037	)
Equity securities	82,385		(58,297		)	24,088			19,538		(12,017		)	7,521			41,872		(15,847		)	26,025
Short-term investments	0		(903		)	(903		)	2		(722		)	(720		)	120		0			120

Contractual Maturity

At December 31, 2013, fixed maturity holdings rated below investment grade and non-rated comprised 1.5% of total investments at fair value. Additionally, the Company owns securities that are credit enhanced by financial guarantors that are subject to uncertainty related to market perception of the guarantors’ ability to perform. Determining the estimated fair value of municipal bonds could become more difficult should markets for these securities become illiquid. The estimated fair values at December 31, 2013 by contractual maturity are shown below. Expected maturities will differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.



	Estimated Fair Value
	(Amounts in thousands)
Fixed maturity securities:
Due in one year or less	$	59,117
Due after one year through five years	336,590
Due after five years through ten years	564,076
Due after ten years	1,600,870
Total	$	2,560,653

Investment Income

A summary of net investment income is shown in the following table:



	Year Ended December 31,
	2013			2012			2011
	(Amounts in thousands)
Fixed maturity securities	$	107,926		$	117,557		$	130,895
Equity securities	18,249			15,831			10,869
Short-term investments	2,702			2,073			1,747
Total investment income	$	128,877		$	135,461		$	143,511
Less: investment expense	(4,339		)	(3,565		)	(2,564		)
Net investment income	$	124,538		$	131,896		$	140,947