Investments (Tables)

12 Months Ended

Dec. 31, 2013

Investments [Abstract]

Schedule of trading securities

Securities accounted for at fair value with changes in fair value recognized in the consolidated income statements by category are as follows:

	December 31, 2013				December 31, 2012
	Fair Value		Amortized Cost		Fair Value		Amortized Cost
U.S. Government and Government agencies	$	1,676,788	$	1,684,832	$	1,865,913	$	1,854,198
Non-U.S. Government and Government agencies	191,776		197,082		261,627		253,657
States, municipalities and political subdivisions	231,555		234,406		40,444		39,342
Corporate debt:
Financial institutions	958,794		943,518		866,140		835,587
Industrials	1,174,047		1,165,448		1,153,909		1,139,706
Utilities	69,426		69,658		69,153		67,463
Mortgage-backed	1,292,502		1,267,863		1,958,373		1,877,854
Asset-backed	505,910		502,543		410,895		405,622
Total fixed maturity investments, trading	$	6,100,798	$	6,065,350	$	6,626,454	$	6,473,429

	December 31, 2013				December 31, 2012
	Fair Value		Cost		Fair Value		Cost
Equity securities	$	699,846	$	647,301	$	523,949	$	480,312
Other invested assets	764,081		658,683		655,888		606,521
	$	1,463,927	$	1,305,984	$	1,179,837	$	1,086,833

Schedule of other invested assets

Details regarding the carrying value, redemption characteristics and unfunded investment commitments of the other invested assets portfolio as of December 31, 2013 and 2012 were as follows:

Fund Type	Carrying Value as of December 31, 2013		Investments with Redemption Restrictions		Estimated Remaining Restriction Period	Investments without Redemption Restrictions		Redemption Frequency(1)	Redemption Notice Period(1)	Unfunded Commitments
Private equity (primary and secondary)	$	144,422	$	144,422	2 - 9 Years	$	—			$	263,519
Mezzanine debt	64,627		64,627		8 - 9 Years	—				198,756
Distressed	7,776		7,776		4 Years	—				5,249
Total private equity	216,825		216,825			—				467,524
Distressed	151,227		151,227		1 - 2 Years	—				—
Equity long/short	99,365		—			99,365		Quarterly	30 -60 Days	—
Multi-strategy	136,958		—			136,958		Quarterly	45 -90 Days	—
Event driven	14,018		—			14,018		Annual	60 Days	—
Relative value credit	113,730		—			113,730		Quarterly	60 Days	—
Total hedge funds	515,298		151,227			364,071				—
High yield loan fund	31,958		—			31,958		Monthly	30 days	—
Total other invested assets at fair value	764,081		368,052			396,029				467,524
Other private securities	147,311		—			147,311				—
Total other invested assets	$	911,392	$	368,052		$	543,340			$	467,524

Fund Type	Carrying Value as of December 31, 2012		Investments with Redemption Restrictions		Estimated Remaining Restriction Period	Investments without Redemption Restrictions		Redemption Frequency(1)	Redemption Notice Period(1)	Unfunded Commitments
Private equity (primary and secondary)	$	111,879	$	111,879	3 - 10 Years	$	—			$	174,772
Mezzanine debt	29,834		29,834		8 - 9 Years	—				85,850
Distressed	9,296		9,296		4 - 6 Years	—				5,794
Total private equity	151,009		151,009			—				266,416
Distressed	138,213		102,088		1 - 2 Years	36,125		Quarterly	45 - 65 Days	—
Equity long/short	169,845		—			169,845		Quarterly	30 -60 Days	—
Multi-strategy	131,713		—			131,713		Quarterly	45 -90 Days	—
Global macro	19,117		—			19,117		Monthly	3 Days	—
Event driven	45,991		—			45,991		Quarterly	60 Days	—
Total hedge funds	504,879		102,088			402,791				—
Total other invested assets at fair value	655,888		253,097			402,791				266,416
Other private securities	127,646		—			127,646				—
Total other invested assets	$	783,534	$	253,097		$	530,437			$	266,416

(1) The redemption frequency and notice periods only apply to the investments without redemption restrictions.

Schedule of net investment income

	Year Ended December 31,
	2013			2012			2011
Fixed maturity investments	$	130,380		$	157,437		$	194,093
Equity securities	19,076			17,080			12,772
Other invested assets	22,937			6,772			2,316
Cash and cash equivalents	2,010			2,319			963
Expenses	(16,839		)	(16,467		)	(14,196		)
Net investment income	$	157,564		$	167,141		$	195,948

Components of realized gains and losses

	Year Ended December 31,
	2013			2012			2011
Gross realized gains on sale of invested assets	$	213,618		$	183,592		$	154,941
Gross realized losses on sale of invested assets	(106,321		)	(51,702		)	(62,169		)
Net realized and unrealized gains (losses) on derivatives	9,485			(3,608		)	(70,090		)
Mark-to-market gains (losses):
Debt securities, trading	(117,577		)	106,328			(8,078		)
Equity securities, trading	4,288			33,018			775
Other invested assets, trading	56,032			38,808			(5,302		)
Net realized investment gains	$	59,525		$	306,436		$	10,077
Proceeds from sale of available for sale securities	$	—		$	236,336		$	646,479